INDEX

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Accelerated Design and Construction

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05-0242 - Precast Bridge Deck Solutions for Rapid Rehabilitation of Truss Bridge
Session 706
ABSTRACT The Bridge and Structures Office completed the design for the Lewis and Clark Bridge deck replacement project in October of 2002. This historic bridge, designed by Joseph B. Strauss of Golden Gate Bridge fame, was built in 1930. It spans the Columbia River between Longview, Washington and Rainier, Oregon. The bridge consists of a 2,720-foot (829m) main through-truss section, a 927-foot (283m) deck truss section on the Oregon side, and a 168-foot (51m) deck truss and a 1,507 foot (459m) 12 span rolled-beam section on the Washington side. The bridge could only be closed to traffic at night from 9:30 P.M. to 5:30 A.M. during construction due to traffic constraints. Night closures were limited to 120 days and single-lane closures were limited to 200 days. The WSDOT Bridge Office designed a method to replace the existing concrete deck on the main through-truss and deck trusses, and for widening the existing deck on the rolled beam spans, using precast concrete deck panels. A total of 103 precast panels with a constant width of 36 feet (11.97m) and variable lengths of 25 to 45 feet (7.62 to 13.72m) were placed on the trusses. For the rolled-beam spans 46 precast panels with a constant width of 4 feet (1.22m) and variable lengths of 58 to 70 feet (17.68 to 21.34m) were placed. Construction is complete as of this date. This paper will examine in depth the design, construction and lifting operations involved with the replacement of the existing bridge deck with precast full width panels. The total cost of this project was $27 million.
     Munindra  Talukdar, Washington State Department of Transportation, talukdm@wsdot.wa.gov

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05-0727 - Design and Construction of a Full-Width, Full-Depth Precast Concrete Deck Slab on Steel Girder Bridge
Session 706
The existing West Sandusky Bridge over I-75, located in Findlay, Ohio, is being replaced with a new 170’ span hybrid steel plate girder bridge with concrete deck. In order to minimize closure times on West Sandusky Street, and reduce traffic delays on I-75 during construction, full-width, full-depth precast concrete deck panels will be used for the construction of the bridge deck. During preliminary design, a variety of alternate precast deck slab designs were considered, and a full-width, full-depth precast deck slab was selected as the preferred alternative. The precast deck panels are post-tensioned both longitudinally and transversely to minimize cracking and improve durability. The deck panels are constructed with shear stud pockets to allow for the installation of shear studs after erection and post-tensioning. During detail design, a finite element analysis of the bridge deck was carried out to determine the required level of prestressing in the deck. A time dependent analysis was subsequently carried out to determine the long term creep effects and post-tensioning losses, including the effects of restraint from the steel girders. A sensitivity analysis was carried out to determine the optimum curing time required prior to stressing the longitudinal post-tensioning tendons and grouting the shear pockets. The steel plate girders were designed for the additional long term creep effects due to the post-tensioning of the deck, which imposed additional axial loads and moments on the steel girders.
     Alex Thomas Harrison, CH2M Hill, aharris1@ch2m.com
     Norman David LeBlanc, Totten Sims Hubicki Associates

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05-0881 - Repairing Railway Spur Roadbed Failure Using Geotextile-Encased Columns
Session 534
When a rail bed failure occurs over soft weak soils the repair options are limited to ground improvement techniques or a deep foundation support system. The geotextile encased column method is a new method of embankment support that minimizes post installation settlement as well as reducing the waiting period after installation and before the application of load. The method was developed in Europe for support of high speed rail systems being constructed over compressible peat deposits. Kleinfelder used the GEC method to repair the failure of a rail spur line located on fill over Bay mud in Oakland California. The method consists of an array of closely spaced rock columns installed through a soft weak soil layer. The rock columns are wrapped in a geotextile sock forming a uniformly shaped column. The columns are installed using a steel pipe casing fitted with a trap door on the bottom. The array of rock columns is covered with a layer of geogrid and 24 inches (61mm) of aggregate base to form the rail bed. A load test was performed to measure settlement. It was concluded that the GEC’s are less costly than other methods such as deep mixing or augercast piles with pedestals, GEC’s can be loaded immediately saving delays for curing or preloading, and GEC’s reduce the post installation settlement compared to stone columns.
     Richard Donovan Short, Kleinfelder, Inc., dshort@kleinfelder.com
     Yogesh  Prashar, Kleinfelder, Inc.

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05-2793 - Method for Automated Discontinuity Analysis of Rock Slopes with Three-Dimensional Laser Scanning
Session 632
This paper describes the interim results of a study to characterize discontinuous rock masses using 3D laser scanning data. One of the main advantages of this method is that now an unbiased, rapid and accurate discontinuity analysis can be done. With 3D laser scanning it is now also possible to measure rock faces whose access is restricted or rock slopes along highways or railway lines where working conditions are hazardous. It is also shown that the proposed method will also be cheaper than traditional manual survey and analysis methods. Laser scanning is a relative new surveying technique, which yields a so-called ‘point cloud’ set of data, where every single point represents a point in 3D space of the scanned rock surface. Since the density of the point cloud can be high (in the order of 5 mm to 1 cm), it allows for an accurate re-construction of the original rock surface in the form of a 3D interpolated and meshed surface, using different interpolation techniques. Through geometric analysis of this 3D mesh and plotting of the facet orientations in a polar plot, it is possible to observe clusters, which represent different rock mass discontinuity sets. With fuzzy k-means clustering algorithms individual discontinuity sets can be outlined automatically and the mean orientations of these identified sets can be computed. Assuming a Fisher’s distribution it is subsequently demonstrated that the facet outliers can be removed. Finally, it is shown that discontinuity set spacings can be calculated as well.
     Siefko  Slob, International Institute for Geo-Information Science and Earth Observation, Netherlands, slob@itc.nl
     Bart  Van Knapen, Delft University of Technology, Netherlands
     Robert  Hack, International Institute for Geo-Information Science and Earth Observation, Netherlands
     Alan Keith Turner, Colorado School of Mines
     John  Kemeny, University of Arizona

Bituminous Materials

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05-0286 - Test for the Presence of Asphalt Antistripping Additive
Session 440
A small device available commercially has been developed that uses litmus paper and a spectrophotometer to analyze vapors from hot liquid asphalt binders and mixtures to determine the percentage of antistripping additive present. Approximately 60 five-point additive content-color index count regressions were performed on binders and mixtures to determine how well the device measured additive content. The regressions basically fit the quadratic format that is used by the manufacturer in the recommended calibration process. The regressions were best when the litmus color index count was calculated by subtracting the initial count of the blank strip from the final count after exposure for the mixtures. Changes to the instrument software and testing temperature were necessary as the investigation progressed to accommodate different grades of binders. After the planned testing was completed, some retesting of the binders was performed using modified equipment and procedures. The changes appeared to improve the consistency of the results; therefore, the author believes that additive testing in binders can be determined within +0.2 percent using the modified equipment and procedures. Test results with mixtures were less accurate than for binders; however, if the vapor trap is modified as described, the accuracy for mixtures should be improved substantially. Since the test can be performed quickly, it would be possible to perform multiple tests on a sample. This would increase the confidence of the test results.
     George William Maupin Jr., Virginia Center for Transportation Innovation and Research, Bill.Maupin@VDOT.Virginia.gov

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05-0346 - Use of Accelerated Loading Equipment for Determination of Long-Term Moisture Susceptibility of Hot-Mix Asphalt
Session 561
Stripping of HMA with moisture susceptible aggregates, under high temperature and aircraft loading has been a persistent problem in some areas of the Logan International Airport in Boston, Massachusetts. These problem mixes generally meet the retained tensile strength criteria, after freeze-thaw conditioning. This study was conducted to evaluate the use of accelerated loading equipment for identifying moisture susceptible mixes, and also to evaluate the effect of lime. Mixes with three different aggregates were prepared with PG 76-28 asphalt binder according to specifications. Specimens were conditioned by three different methods, 1) multiple cycles of freeze-thaw, 2) wet trafficking with the Model Mobile Load Simulator (MMLS3) and 3) cycles of stress with the Moisture Induced Stress Tester, (MIST). Thereafter the respective indirect tensile strengths were determined. The results showed that accelerated loading can provide useful information for evaluating resistance of HMA to moisture damage under traffic at high temperature. For mixes to have adequate resistance to moisture damage by volumetric expansion-contraction, acceptable tensile strength tests were needed after at least six freeze-thaw conditioning cycles. The evaluation of resistance to moisture damage under traffic at high temperature using moisture stress conditioning proved very promising. The methods should be investigated further. The use of hydrated lime, improved the resistance of HMA against moisture induced stress damage at high temperatures. On the basis of these conclusions, it is recommended that testing protocols, consisting of both freeze-thaw and accelerated loading/moisture induced stress testing at high temperature, be used for evaluating the most cost-effective anti-stripping agent (liquid or solid).
     Rajib B. Mallick, Worcester Polytechnic Institute, rajib@wpi.edu
     Robert  Pelland, Massachusetts Port Authority
     Frederick  Hugo P.E., University of Stellenbosch, South Africa

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05-0348 - Guidelines for Prime Coat Usage on Low-Volume Roads
Session 336
Prime coat has a purpose in the pavement construction process, yet many times prime is misused or eliminated during the project. While most of the time no harm appears to occur to the roadway and thus may be viewed as acceptable, technical guidance is warranted to assure appropriate usage. The objective of this study was to produce a prime coat guide publication developed for Central Federal Lands Highway Division (CFLHD) project development and field personnel to provide decision-making guidance on how to use, when to keep, and when to eliminate prime coat. The literature search, which focused on handbooks and technical reports, was conducted along with a review of agency construction specifications. A phone survey of current practice of state DOTs from the region was undertaken to provide information on current practice. Finally, a review of the potential harmful and positive environmental effects of the prime coat process, including the various bituminous products used, was undertaken. Based on the information collected, a guideline for project development and field personnel was developed. The guideline provides decision-making guidance on how to use, when to keep, and when to eliminate prime coats.
     Stephen  Cross, Oklahoma State University, steve.cross@okstate.edu
     Michael David Voth, Federal Highway Administration
     Pramed P Shrestha, Oklahoma State University

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05-0389 - Practical Procedure for Developing Dynamic Modulus Master Curves for Pavement Structural Design
Session 813
A dynamic modulus master curve for asphalt concrete is a critical input for flexible pavement design in the Mechanistic-Empirical Pavement Design Guide developed in National Cooperative Highway Research Program (NCHRP) Project 1-37A. The recommended testing to develop the modulus master curve is presented in AASHTO Provisional Standard TP 62-03¡§Standard Method of Test for Determining Dynamic Modulus of Hot-Mix Asphalt Concrete Mixtures.¡¨ It includes testing at least two replicate specimens at five temperatures between 14 and 130 „aF (-10 and 54.4 „aC) and six loading rates between 0.1 and 25 Hz. The master curve and shift factors are then developed from this database of 60 measured moduli using numerical optimization. This testing requires substantial effort, and the data collected at extremely high and low temperatures are highly variable. Additionally, there is much overlap in the measured data, which is not needed when numerical methods are used to perform the time-temperature shifting for the master curve. This paper presents an alternative to the testing sequence specified in AASHTO TP62-03. It requires testing at only three temperatures between 4 and 115 „aF (4 and 46.6 „aC) and four rates of loading between 0.01 and 10 Hz. An analysis of data collected using the two approaches shows that comparable master curves are obtained. This alternative testing sequence can be used in conjunction with the Simple Performance Test System developed in NCHRP Project 9-29 to develop master curves for structural design.
     Ramon  Bonaquist, Advanced Asphalt Technologies, LLC, aatt@erols.com
     Donald Walter Christensen Jr., Advanced Asphalt Technologies, LLC

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05-0483 - Asphalt Mix Design Method for Permeability
Session 561
Because of the observed porosity of new Superpave mixes, the Virginia Transportation Research Council conducted several investigations of permeability. As a result of these investigations and other related national studies, a mix design permeability test method was developed. The method involves testing a group of specimens prepared in the lab at a range of air-void contents and developing a permeability-void regression plot. From the regression, the permeability of pavement can be estimated. The purpose of this project was to compare results between two labs using mixtures from 11 paving projects. There was general agreement between permeability-air voids regressions resulting from the testing for the two labs. In addition, testing of cores from six of the projects indicated that the lab method estimates pavement permeability rather well. Implementation of the test method by the Virginia Department of Transportation is discussed.
     George William Maupin Jr., Virginia Center for Transportation Innovation and Research, Bill.Maupin@VDOT.Virginia.gov

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05-0508 - Field Evaluation of Porous Friction Course for Noise Control
Session 480
In 2003, the Indiana Department of Transportation allowed a test section of Porous Friction Course (PFC) to be placed on I74 east of Indianapolis. This paper summarizes the design, construction and early performance of that surface compared to an adjacent SMA surface and a conventional Superpave HMA surface. All three mixes included steel slag aggregate and a PG76-22 binder. The PFC was designed at 18-22% air voids to provide a permeable surface. Noise measurements were made on all three surfaces using both the pass-by and close-proximity methods. The three surfaces were also evaluated in terms of surface texture using the Circular Texture Meter and friction using the Dynamic Friction Tester and towed friction trailer. Splash and spray were judged qualitatively. The early performance indicates that the PFC produced significantly lower noise levels, higher surface texture and friction, and reduced splash and spray compared to the other two surface types.
     Rebecca S. McDaniel, Purdue University, rsmcdani@purdue.edu
     William D. Thornton, Purdue University

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05-0537 - Establishment of the Precision of a Rapid-Angle Measurement Device for Superpave Gyratory Compactors
Session 602
Superpave hot-mix asphalt (HMA) specimens are compacted in the laboratory using the Superpave gyratory compactor (SGC) through the application of pressure and an applied angle of gyration. The original compaction specification for the SGC requires the angle of gyration to be 22±0.35 mrad (1.25±0.02 degrees), measured externally to the compaction mold. Questions concerning the ability of different compactors to produce HMA specimens of the same mix having the same density led to the development of the Dynamic Angle Validation (DAV) kit, which measures the angle of gyration internally (on the inside of the mold). The DAV procedure requires the use of HMA to measure the internal angle of gyration. Due to practical limitations of performing measurements using HMA and questions concerning the “proper” HMA mix to use in the measurements, a device – the Rapid Angle Measurement (RAM) – was introduced which effectively simulates the load placed on the SGC by a hot-mix asphalt specimen. An interlaboratory study was conducted in accordance with ASTM E691-99 to establish the precision of the internal angle measurement provided by the RAM. A total of eleven RAM units and five SGC models were included in the study. Based on the study data, estimates were developed of both repeatability (within lab) and reproducibility (between lab) for the RAM device for all five SGC models. It is recommended that all devices with the reported ability to measure internal angle of gyration be subjected to a similar interlaboratory study in order to compare devices on an equal basis.
     Kevin D. Hall, University of Arkansas, Fayetteville, kdhall@uark.edu
     Tamara  Easley, Arkansas State Highway and Transportation Department

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05-0891 - Estimating Results of a Proposed Simple Performance Test for Hot-Mix Asphalt from Superpave Gyratory Compactor Results
Session 602
Several approaches were introduced lately to characterize the performance related properties of asphalt mixtures. The majority of the efforts are focused on developing special equipment to test at conditions similar to those acting on the pavements due to moving traffic. Because the Superpave gyratory compactor (SGC) is used routinely for compaction, and because it has components to measure load and densification, this study was intended to use it as a basis for estimating the stability of asphalt mixtures as a surrogate or an estimate for results of the proposed method for the simple performance test. Several asphalt mixtures were produced using four different sources, different asphalt contents, and different gradations. Every mixture was compacted using the SGC. To evaluate if the results from the SGC can be related to rutting of mixtures as measured by the new repeated compression test procedure for rutting measurements recommended by the National Cooperative Highway Research Program project 9-19 and used in the AASHTO 2002 pavement design manual. Densification curves produced by the SGC were used to determine volumetric properties of the mix as well as the calculation of the traffic densification index (TDI), which is the value of the area under the densification curve from 92% density to 98% density, represents the densification experienced by the traffic loading during pavement service life. One more index is calculated, traffic force index (TFI). The TFI is the amount of work done to change the density of the mix from 92% to 98% measured using a special accessory added to the SGC while compaction is taking place called the pressure distributor analyzer (PDA). The results from the mixture rutting tests were used to estimate the rutting rate and the flow number (FN), which is the point at which the mixture starts to exhibit tertiary flow. The flow number, which is considered an important mixture property, is shown to have a strong correlation to the TFI derived from the mixtures resistance behavior measured in the SGC and the PDA. The TFI was found to be strongly correlated to the TDI, giving the opportunity to estimate the mixture resistance to compaction forces using its volumetric behavior. The main finding of the study is that SGC appears to give information that can be used to characterize the stability of the mixtures. Such information could be used as an initial screening criterion to select mixture for various traffic levels.
     Ahmed Fatin Faheem PhD, Temple University, afaheem@temple.edu
     Hussain U. Bahia, University of Wisconsin, Madison
     Hossein  Ajideh, County of Orange

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05-1175 - Performance Evaluation of Hot-Mix Asphalt Using Rotary Loaded-Wheel Testing
Session 641
Permanent deformation and moisture damage (i.e., rutting and stripping) are two predominant hot mix asphalt (HMA) distresses. Rutting can be caused by many factors, including stripping, all of which result in reduced HMA shear strength. Hot mix asphalt stripping evaluation is a source of significant industry discussion and debate. Transportation agencies use a number of methods to evaluate stripping, with many methods customized by agencies depending upon local concerns and environmental conditions. Today, many agencies use some type of loaded wheel testing, with associated mix “pass/fail” criteria, as part of the mix design acceptance procedure. This process is often referred to as “proof” testing and provides a higher confidence that the HMA mix will perform satisfactory during service conditions. A new device, the rotary wheel tester, has been recently developed to conduct rutting and stripping performance evaluation of HMA mixes. This device operates on a similar principle as the Hamburg wheel tester, with the main difference being the specimen is loaded along its diameter instead of from the top. The cost of the rotary wheel tester is less than half that of the Hamburg wheel tester. Testing was conducted to determine if the rotary wheel tester could distinguish between good and poor performing mixes and to determine if PG 76-22 or PG 67-22 plus hydrated lime improves mix performance. Results indicate the rotary wheel tester is an easy to use testing device that appears to provide reasonable prediction of rutting and stripping performance of HMA mixes. It also appears that PG 76-22 asphalt binder improves mix performance to a greater extent than PG 67-22 plus hydrated lime.
     Shane  Buchanan, APAC, Inc., shane.buchanan@oldcastlematerials.com
     Benjamin J. Smith, Brown and Mitchell Inc.

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05-1285 - Predicting Field Permeability from Testing Hot-Mix Asphalt Specimens Produced by Superpave Gyratory Compactor
Session 440
This study was conducted to develop laboratory and field permeability testing procedures for design and quality control of Superpave mixtures in Wisconsin. A total of 16 mixes used on 9 field projects, including fine-graded and coarse-graded mixes, were evaluated. The in-place field permeability was measured by using the NCAT device; field cores were taken for measuring permeability in the laboratory by using the ASTM D5084 method; and laboratory compaction was used to prepare and test samples from loose mixtures recovered from the field. Two compaction procedures, called Method A and Method B were used in this study to produce Superpave Gyratory Compacted (SGC) specimens that have similar thickness, air voids, and aggregate orientation of the field cores. The result indicates that Method B, which is based on using Ndesign gyrations for different sample sizes, can be used to produce samples that give permeability values similar to values measured for field cores. The results of this study also indicate a good relationship between field permeability (using the NCAT device) and lab permeability measured on field cores of fine-graded mixes with amount of passing No. 8 sieve (P8) higher than 45%. However, the relationship between field permeability and lab permeability measured on field cores of coarse-graded mix (P8 lower than 40%) is very poor. It is therefore concluded that the NCAT permeability device could possibly be used in the field for fine-graded mix (with P8 higher than 45%) to measure a permeability index that is related to the true permeability of field cores as measured by the ASTM D5084. However, to measure the field permeability of coarse-graded mix (P8 lower than 40%), an approach to prevent water leakage along the sealant due to rough pavement surface should be established. For coarse graded mixtures, there appears to be no current alternative better than taking field cores and testing them in the laboratory. For estimating permeability during mixture design, a simple method for preparing and testing permeability of SGC specimens and interpolating based on expected field density is introduced. The results represent a good estimate of the expected in-place field permeability.
     Kunnawee  Kanitpong, Asian Institute of Technology, Thailand, kanitpon@ait.ac.th
     Hussain U. Bahia, University of Wisconsin, Madison
     Jeffrey S. Russell, University of Wisconsin, Madison
     Robert  Schmitt, University of Wisconsin, Platteville

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05-1291 - Evaluation of the Gradation Effect on the Dynamic Modulus
Session 813
The importance of aggregate characteristics has been emphasized in the SuperpaveTM asphalt mixture design procedure. However, criteria for guidelines for the selection of suitable aggregate gradations have been neglected other than gradation limits for different nominal maximum size aggregate blends, including the restricted zone. With the move toward mechanistic-empirical pavement design, the dynamic modulus is used to account for mixture properties in the pavement design. It is of significant importance to mix designers to possess a framework for determining how to optimize a mixture for ensure an adequate dynamic modulus. This paper presents the results from a study of the effects of gradation characteristics on the dynamic modulus. Power law-based gradation factors are obtained for 13 different aggregate gradations (coarse- and fine-graded) composed of limestone and granite aggregates. These gradations factors were used to identify and evaluate relationships between the gradation factors and the dynamic modulus at higher temperature (40°C). Subsequently, a tentative framework was established for optimizing mixture gradations for dynamic modulus values. The findings illustrate that gradation factors based on power law parameters can be used to optimize mixture gradations for key mixture properties, such as the dynamic modulus. The results also demonstrate the critical nature of aggregate gradation in achieving desired mixture properties.
     Bjorn  Birgisson, KTH Royal Institute of Technology, Sweden, bjornbir@kth.se
     Guangming  Wang, Quality Engineering Solutions, Inc.

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05-1309 - Evaluation of a Predicted Dynamic Modulus for Florida Mixtures
Session 813
The new 2002 AASHTO Guide for the Design of Pavement Structures is based on mechanistic principles and requires the dynamic modulus as input to compute stress, strain, and rutting and cracking damage in flexible pavements. The 2002 AASHTO Guide has 3 different levels of analysis, which depend on the importance of the pavement structure in question. Dynamic modulus testing is required for Level 1 pavement analysis, whereas the Level 2 and Level 3 pavement analysis requires no laboratory test data. Instead, a predictive dynamic modulus equation is used to generate input values. It is of significant importance to state agencies to understand how well the dynamic modulus for locally available materials compares to the predicted dynamic modulus. This paper presents the results of a study by the Florida Department of Transportation and the University of Florida that focused on the evaluation of the dynamic modulus predictive equation used in the new AASHTO 2002 Guide for mixtures typical to Florida. The resulting research program consisted of dynamic modulus testing of 28 mixtures common to Florida. The results showed that the predictive modulus equation used in the new AASHTO 2002 flexible pavement design guide appeared on the average to work well for Florida mixtures, when used with a multiplier to account for the uniqueness of local mixtures. The results of the study also identified optimal viscosity-temperature relationships that result in the closest correspondence between measured and predicted dynamic modulus values.
     Bjorn  Birgisson, KTH Royal Institute of Technology, Sweden, bjornbir@kth.se
     Gregory Allen Sholar, Florida Department of Transportation
     Guangming  Wang, Quality Engineering Solutions, Inc.

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05-1511 - Maintenance and Rehabilitation of Low-Volume Pavements in Washington State
Session 336
The vast majority of pavements worldwide can be classified as low-volume. Pavement maintenance and rehabilitation practices on these roads are vital to their continued serviceability. Proven successful and efficient strategies are in demand considering that low-volume roads are typically managed by agencies with extremely limited resources. The Washington State Pavement Management System (WSPMS), which has been functioning continuously for over 30 years, provides a rich data set from which to investigate maintenance and rehabilitation practices on low-volume pavements in Washington State. This investigation seeks to determine common maintenance, rehabilitation, design and material characteristics in WSDOT managed low-volume pavements and measures of their success. Records indicate that over two-thirds of WSDOT’s low-volume pavements are bituminous surface treatments, while almost one-third are hot mix asphalt surfaced pavements. These pavements, many of which have lasted in excess of 35 years, are in relatively good condition and are typically subject only to periodic rehabilitation treatments every 8 to 20 years and responsive pothole patching. This evidence suggests that the concept of a long-lasting low-volume pavement is viable and, in fact, already exists. More study is required to determine the physical, construction and preservation principles behind this phenomenon.
     Stephen T. Muench, University of Washington, stmuench@uw.edu
     George C. White, University of Washington
     Joe P. Mahoney, University of Washington
     Nadarajah  Sivaneswaran, Federal Highway Administration
     Linda M. Pierce, Applied Pavement Technology, Inc.

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05-1518 - Investigation of the CoreLok for Maximum, Aggregate, and Bulk Specific Gravity Tests
Session 473
The Florida Department of Transportation uses long established test procedures to determine the maximum specific gravity (Gmm) and bulk specific gravity (Gmb) of asphalt mixtures and bulk specific gravity (Gsb) of aggregates. The CoreLok, a vacuum-sealing device that can be used to determine these properties, was evaluated by the Department for these four test procedures. With respect to the Gmm test procedure, for mixtures containing non-absorptive granites, the CoreLok determined equivalent results compared to the Department’s test procedure. However, for mixtures containing absorptive limestones, the CoreLok determined higher Gmm values compared to the Department’s test procedure. The apparent reason for the discrepancy is because the CoreLok does not determine a saturated surface-dry condition of the sample. With respect to the aggregate specific gravity test procedures, the CoreLok provided equivalent test results to the Department’s test procedure for the non-absorptive fine aggregates only. For the absorptive fine aggregates and all of the coarse aggregates, the CoreLok determined significantly different Gsb test results compared to the Department’s test procedures. The CoreLok may be suitable for determining Gmb for coarse graded compacted specimens with high porosity and air voids. There are concerns with the accuracy of the CoreLok results due to the bridging effect of the plastic bag over the large surface voids and due to the CoreLok’s significant underestimation of the specific gravity of a solid aluminum cylinder.
     Gregory Allen Sholar, Florida Department of Transportation, gregory.sholar@dot.state.fl.us
     Gale C. Page, Florida Department of Transportation
     James A. Musselman, Florida Department of Transportation
     Patrick B Upshaw, Florida Department of Transportation
     Howard L. Moseley, Florida Department of Transportation

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05-1655 - Evaluation of Two Compaction Levels for Designing Stone Matrix Asphalt
Session 641
Current Stone Matrix Asphalt (SMA) design guidelines list two compaction options to design SMA, 50 blows Marshall or 100 Gyrations with the Superpave Gyratory Compactor (SGC). However, some states have found that 100 gyrations with SGC are excessive for their materials. In this study, a lower compaction level of 65 gyrations was used to compare with the standard 100 gyrations to design SMA mixtures. Results showed that mixtures designed by 65 gyrations had an average of 0.7 percent higher optimum asphalt content and 1.5 percent higher VMA than those designed by 100 gyrations. All mixtures designed by 65 gyrations met the minimum asphalt content and VMA requirements for SMA, while only 8 of 15 mixtures designed by 100 gyrations met these two requirements. Compaction at 100 gyrations resulted in an additional 0.62 percent average aggregate breakdown at the critical sieve as compared to 65 gyrations. SMA mixtures designed by 65 gyrations had an average Asphalt Pavement Analyzer (APA) rut depth of 3.9 mm. Thirteen of fifteen mixtures performed well if 5.0 mm is set as maximum allowed rut depth. Based on this study, it was concluded that 65 gyrations can be used to design a more durable SMA mixture, while still maintaining the good rutting resistance that SMA mixtures are noted for. The successful design by 65 gyrations for all five aggregates in this study indicates that a lower design compaction level may allow the use of more aggregate sources for SMA mixtures.
     Hongbin  Xie, National Center for Asphalt Technology, xiehong@auburn.edu
     Donald E. Watson, National Center for Asphalt Technology
     Elton Ray Brown, U.S. Army Engineer Research and Development Center

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05-1766 - Comparison of Thin-Lift Hot-Mix Asphalt Surface Course Mixes in New Jersey
Session 480
The use of thin-lift HMA surface course mixes is starting gaining wide acceptance in the United States as a means of improving both ride quality and safety. These materials are generally classified as having an open-graded/gap-graded aggregate skeleton, nominal aggregate sizes of 12.5mm or less, higher than normal asphalt binder contents, and are placed in thickness’ less than one inch. The use of the thin-lift materials has found to improve wet weather driving conditions, reduce traffic noise associated with the tire/pavement interface, and improve the ride quality measurements. Thin-lift HMA surface course mixes typically found in New Jersey consist of open-graded friction courses (OGFC) and Novachip®, with a few roadway sections using micro-surfacing and stone-mastic asphalt (SMA). Each of these material types were evaluated to provide an assessment of their ride quality and safety. These thin-lift materials were compared to in-service dense-graded asphalt mixes (DGA) and Portland cement concrete (PCC). The PCC had surfaces that consisted on no treatment, transverse tined, and diamond grind. Noise measurements utilizing the Close Proximity method (CPX), wet skid resistance, and ride quality data consisting of RQI and IRI were used to establish “performance” comparisons between the different surface courses. The “performance” information, along with current costs associated with the materials and construction, can provide a means of establishing a cost-effectiveness for utilizing these surface treatments under specific situational conditions.
     Thomas A. Bennert, Rutgers University, bennert@rci.rutgers.edu
     Frank  Fee, Asphalt Pavement Technology, LLC
     Eileen C. Sheehy, New Jersey Department of Transportation
     Andris A. Jumikis PE, New Jersey Department of Transportation
     Robert W. Sauber, Consultant

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05-1951 - Development of Surfacing Criteria for Low-Volume Roads in South Dakota
Session 336
On a daily basis, local road agencies in South Dakota face the challenge of how to cost-effectively maintain low-volume roads. Specifically, agencies are faced with the decision of determining when it is most economical to maintain, upgrade, or downgrade a road’s existing surface. In order to assist decision makers with these types of maintenance and rehabilitation decisions, the South Dakota Department of Transportation (SDDOT) initiated a research study in 2002 to investigate surfacing criteria for low-volume roads (LVR). The overall objective of this research study is to create a process that allows the user to compare the costs associated with different types of roads to provide assistance in deciding which surface type (hot-mix asphalt [HMA], blotter, gravel, or stabilized gravel) is most economical under a specific set of circumstances. In addition to incorporating economic factors into the analysis, the process allows the user to consider other non-economic factors that are more subjective and difficult to quantify. The process used during this study is flexible enough to allow users to consider any combination of agency costs incurred by the agency for maintaining its roads, non-agency (user) cost factors such as vehicle operating costs or crash potential, and non-economic factors such as politics and housing densities. The methodology was created using agency cost and user cost models that were developed based upon specific road section information supplied by various local agencies in South Dakota, average daily traffic (ADT) and crash occurrence information supplied by the SDDOT, information obtained through a literature search, and input from members of the project’s Technical Panel.
     Angela S. Wolters, Applied Pavement Technology, Inc.
     Kathryn A. Zimmerman P.E., Applied Pavement Technology, Inc., kzimmerman@appliedpavement.com
     David L. Huft, South Dakota Department of Transportation
     Paul A. Oien, South Dakota Department of Transportation

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05-1976 - Evaluation of Caltrans Test Method for Measuring Resistance of Compacted Bituminous Mixture to Moisture-Induced Damage
Session 440
This paper presents an evaluation of test results from two round robin tests conducted by the California Department of Transportation (Caltrans) in 2003 using the newly developed test for measuring resistance of compacted bituminous mixture to moisture induced damage (California Test 371) and the development of preliminary precision statements resulting from the round robin tests. The test is a modification of the AASHTO T-283-89 procedure using the recommendations of NCHRP Project 9-13. Twenty laboratories statewide participated in the tests. Thirteen of the laboratories participated twice. The material used in the round robin tests was dense-graded hot-mix asphalt. The loose mixtures were prepared by one laboratory and the same Rice value was provided to all laboratories. The evaluation includes examination of test data outliers, evaluation of means, precision, and test repeatability. The evaluation indicates the following: • The standard deviation of the tensile strength ratio (TSR) values from the two round robin tests falls within the ASTM D 4867 suggested between-laboratory precision criterion. However, the TSR range exceeds the ASTM D2s criterion. • More than half of the participating laboratories met the ASTM D 4867 within-laboratory precision criteria. • For evaluation of test repeatability, data from 11 participating laboratories indicate that nine laboratories achieved the same mean air void content and saturation for both round robin test series. Also, at least 4 of 11 laboratories achieved the same mean tensile strength for both round robin test series. Preliminary precision statements for inclusion in the newly developed test method were developed as below: • Within-Laboratory Precision o Single-operator standard deviation (1s) of tensile strength (unconditioned or conditioned samples) is 74 kPa o D2s range is 210 kPa • Between-Laboratory Precision o Multi-laboratory standard deviation of the TSR is 8% o D2s range is 23% The recommended precision statements developed as a part of this study may be refined as more test data are generated.
     Haiping  Zhou P.E., California Department of Transportation, haiping_zhou@dot.ca.gov

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05-1980 - Comparison of Superpave and Marshall Mix Performance in Alabama
Session 641
The Alabama Department of Transportation specifies the Superpave design system for the majority of its dense-graded HMA mixes. However, there is concern that the number of design gyrations (NDesign) may be too high for specified traffic levels. Mixes designed with an NDesign level too high would be rut resistant, but may be difficult to compact in the field and may suffer from durability problems such as premature cracking and raveling. The objective of this project is to evaluate the performance of Alabama’s mixes designed using Superpave criteria and compare them to the performance of Alabama’s Marshall designed mixes to determine if current NDesign levels should be adjusted. The following conclusions are based on an evaluation of 25 Marshall and Superpave projects placed about the same time and serving under approximately the same traffic conditions. 1. Both Marshall and Superpave mixtures are generally performing quite well with little rutting and cracking after a period of about four years. 2. It is likely that most Marshall and Superpave mixtures will not reach the design air voids of 4.0 percent during the life of the pavement. After four years, the average air voids measured in the wheelpaths was 5.3 percent for Marshall mixes and 5.9 percent for Superpave mixtures. 3. It appears the durability of Superpave mixtures can be improved by increasing the asphalt content without adversely affecting the rutting resistance. However, practitioners are cautioned to closely monitor rutting indicators during mixture design, production, and construction. Keywords: Marshall, Superpave, rutting, cracking, gyratory
     Donald E. Watson, National Center for Asphalt Technology, watsode@auburn.edu
     Elton Ray Brown, U.S. Army Engineer Research and Development Center
     Jason Roox Moore, Auburn University

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05-1981 - Evaluation of Circular Texture Meter for Measuring Surface Texture of Pavements
Session 512
The CT Meter is a laser based device for measuring the mean profile depth (MPD) of a pavement at a static location. Both MPD measurements from the CT Meter and mean texture depth (MTD) measurements from the sand patch test were obtained in five random locations in each of 45 section of the 2000 National Center for Asphalt Technology (NCAT) Test Track. The NCAT Test Track provides a wide range of surface types including: coarse and fine dense graded Superpave mixes, Hveem mixes, Stone Mastic Asphalt (SMA) and Novachip. Testing indicated that CT Meter produced comparable results to the ASTM E965 Sand Patch Test. When open-graded mixtures were excluded, this study indicated that the offset was non-significant between CT Meter and Sand Patch test results. Previously developed equations to predict macrotexture were found to be inadequate for the wide range of mix types and aggregate types found at the NCAT Test Track. An equation was developed to relate fineness modulus to macrotexture. This equation was validated with independent data collected by Virginia Transportation Research Council. Testing conducted as part of a mini round robin indicated that two readings should be averaged to represent a single CT Meter measurement. The within-lab coefficient of variation for the CT Meter is estimated to be 2.3 percent. The between lab coefficient of variation for the CT Meter is estimated to be 4.2 percent. Both estimates are based on the average of two tests being reported as a single measurement. This indicates that the CT Meter is more variable than the sand patch test. However, less technician skill is required to operate the CT Meter.
     Brian D. Prowell, Advanced Materials Services, LLC, Brian@AMSLLC.US
     Doug I. Hanson, No Organization

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05-2069 - Design of a Specific Bituminous Surfacing for the World's Highest Orthotropic Steel Deck Bridge: France's Millau Viaduct
Session 641
This paper presents a rational approach for the performance-based design of bituminous wearing surfacings on orthogonally anisotropic steel bridges. Basically, the behavior of bituminous surfacings on steel orthotropic decks, under heavy truck traffic and environmental conditions, is highly complex. Both the geometry of the structure and the very high flexibility of metallic plates make the deformations and stresses very severe in steel bridge surfacings. In particular, the repeated loading make the fatigue strength be an important parameter for the design of such bituminous wearing courses. In addition, these specific surfacings must also have durability over the expected temperature range, they must be resistant to thermal cracking at low temperatures and to rutting at high temperatures. The technical studies led in parallel to the construction of the Millau Viaduct (France) –the highest bridge in the world– have provided in particular the opportunity of new progress in the development of appropriate laboratory testing equipment and of an original polymer-modified surfacing. A comprehensive research program including both a large laboratory testing campaign and a finite element parametric study was performed in order to develop a handy tool for design of plate surfacings.
     Bernard  Heritier, Appia, France
     Francois  Olard, Eiffage Travaux Publics, France, francois.olard@eiffage.com
     Frédéric  Loup, Appia, France
     Serge  Krafft, Appia, France

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05-2089 - Effect of Construction Quality, Temperature, and Rutting on Initiation of Top-Down Cracking
Session 800
Top-down cracking (TDC) is a flexible pavement distress caused by a number of factors, including, high contact stresses from truck tires, mix design characteristics, (e.g., binder type and aggregate gradation) and poor construction quality, (e.g., segregation and compaction methods). This paper presents the findings of a study seeking to quantify the effect of these factors on TDC. It consists of a laboratory component involving an accelerated Wheel Tracking device and a modeling component involving a 3-D non-linear viscoelastic finite element model. The laboratory component of the study involved 17 asphalt bituminous slabs constructed to simulate the variation in material properties observed in the field as part of an earlier forensic TDC study. The effect of air voids, bitumen content and type, aggregate gradation and segregation on TDC were studied under 3 temperature conditions. Air voids, segregation and binder content were found to have a significant effect on TDC for all the temperatures tested. Modeling the TDC involved laboratory testing to establish the viscoelastic and tensile strength properties of the asphalt mixtures tested. It was found that the rutted surface contributes significantly to TDC initiation.
     Elisabete Fraga Freitas, University of Minho, Portugal, efreitas@civil.uminho.pt
     Paulo Antonio Alves Pereira, University of Minho, Portugal
     Luís Picado Santos, Universidade de Coimbra, Portugal
     A. Thomas Papagiannakis, University of Texas, San Antonio

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05-2112 - Evaluation of Witczak Dynamic Modulus Prediction Model
Session 813
The dynamic modulus |E*| is a fundamental property defining the response of hot mix asphalt (HMA) mixtures in flexible pavement systems and is one of the primary material inputs in the mechanistic-empirical design methodology developed in NCHRP Project 1-37A. An empirical predictive model for estimating |E*| for HMA has been developed based on work by Witczak and co-workers over many years (Andrei et al., 1999). This model relates |E*| to loading rate, temperature-dependent binder viscosity, and mixture volumetric and gradation parameters. The accuracy and robustness of the Witczak |E*| model is evaluated through a set of sensitivity and validation studies. Although the results from the validation study of 26 mixtures suggest that the model may overestimate |E*|, particularly at higher temperatures, the overall findings confirm that the Witczak model can provide sufficiently accurate and robust estimates of |E*| for use in mechanistic-empirical pavement performance prediction and design. Because of the strong dominance of temperature influences over other mixture parameters, however, the model may not be able to make fine distinctions between predicted performance for different mixtures under the same environmental and other conditions. Laboratory testing of |E*| may still be required for this purpose.
     Charles W. Schwartz, University of Maryland, schwartz@umd.edu

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05-2315 - Critical Evaluation of Use of the Procedure of Superpave Volumetric Mixture Design Procedure for Modified Binders
Session 602
This study was conducted to examine the possible interference of modified binders with the standard procedure for volumetric mixture design used in the Superpave system. Sensitivity of volumetric properties and moisture damage performance was evaluated using four binders modified with two different technologies (Polymer and no-additive modifications). The study included three tasks to evaluate effects of compaction temperatures (in the range of 72¡ÆC to 148¡ÆC), effects of vertical pressure (in the range of 200 kPa to 600kPa), and moisture damage according to the AASHTO T283 procedure. The Zero Shear Viscosity concepts were used to estimate mixing and compaction temperatures, compaction energy index was used to study changes in compaction effort, and cohesion and adhesion of binders were measured. The results indicate that temperature effects, within a reasonable range, are somewhat marginal and that unless temperatures are reduced to below 80¡ÆC, the effects on volumetric properties are rather small. It was also found that using a target viscosity of 1.5 Pa¡¤s for mixing and 3.0 Pa¡¤s for compaction can provide very reasonable compaction temperatures, particularly if Zero Shear Viscosity is used. These criteria for temperatures worked well for the grades and type of modification used in the study. The vertical stress used in the gyratory compactor showed very significant effects on volumetric properties. Changing pressure from 600 kPa to 300 kPa resulted in 3.0 to 4.0 % increase in air voids, which is more significant than changing viscosity by more than 10 times. It is therefore postulated that the focus on keeping temperature high during compaction in the lab and in the field could be un-founded. With increasing pressure during compaction in the lab or weight of roller in the field, significant changes in density could be achieved. Moisture damage does not appear to be affected significantly by the variation in binder viscosity profiles for the binders and aggregates used in this study. Because of the limited sample size, more work is needed in this area to study effect of mixing and compaction temperatures on moisture damage.
     Dong-Woo  Cho, University of Wisconsin, Madison, dcho@cae.wisc.edu
     Hussain U. Bahia, University of Wisconsin, Madison
     Nabil  Kamel, Asphalt Research and Technical Services, Inc., Canada

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05-2472 - Control of Superpave Gyratory Compactor’s Internal Angle of Gyration: Experience of the Utah Department of Transportation
Session 602
The State of Utah Department of Transportation (UDOT) started a program to use the Dynamic Angle Validator (DAV) to measure the internal angle of all Superpave gyratory compactors (SGCs) used in construction of hot-mix asphalt in the State. The results show that differences in internal angle exist unless the compactors are calibrated regularly and technicians are trained in laboratory procedures. Once the program was in place, the internal angle of 36 out of 46 SGCs tested was within the limits of 1.16  0.03º. However, seven SGCs, all of one model, had angles between 0.860 and 1.212 degrees with an average angle of 1.026 degrees even after calibration. If the limits are narrowed to 1.16 ± 0.02º, then only 28 out of 46 SGCs (60%) of the SGCs will be within these range The results also show that it is possible to obtain acceptable density values on specimens compacted using machines that have internal angles outside the proposed range. It was concluded that the internal angle limits of 1.16  0.03º are too restrictive for the machines and types of mixes used in the State of Utah. It was recommended that the equipment be calibrated often, that molds be checked for cleanliness and dents, and that temperature measuring devices be verified. In those cases where there are large differences in measured properties of compacted samples even after repeated calibration, the internal angle should be verified since it was noted that external calibration did not always correct the internal angle. This will help reduce conflict between State Labs and consultants.
     Pedro  Romero, University of Utah, romero@civil.utah.edu
     Murari Man Pradhan, Arizona Department of Transportation

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05-2566 - Road to Quiet Neighborhoods in Arizona
Session 480
The Arizona Quiet Pavement Pilot Program (QP3) is a $34 million project implemented to reduce highway related traffic noise. This pilot program represents the first time that pavement surface type has been allowed as a noise mitigation strategy on federally funded projects. The program will overlay most of the Phoenix metropolitan area PCCP with one inch of ARFC. As a condition of using pavement type as a mitigation strategy, ADOT developed a ten-year, $2 million research program to evaluate the efficacy of using ARFC. Historically, pavement surface type was not considered a permanent solution due to the change in acoustic properties with time. This research program will evaluate the change in pavement acoustic properties through three means, (1) conventional roadside testing (eg far field measurements), (2) the use of near field measurements, both Close Proximity (CPX) and Sound Intensity (SI), and (3) far field measurements taken within the surrounding neighborhoods. This paper provides an overview of the program development, presents the research conducted to support the decision to overlay the urban freeway, and the status of current research. Particular emphasis is placed on the development and use of near field measurement systems consisting of CPX and SI Preliminary results from the research to date indicate that the near field measurement systems are providing meaningful assessments of pavement acoustic performance and the SI and CPX methods compare favorably. The overlays placed reduce the near field measurement levels between 6 to 11 dBA. Average reductions of 5 dBA occurred in the neighborhoods.
     Larry A. Scofield, International Grooving and Grinding Association, lscofield@pavement.com
     Paul  Donavan, Illingworth & Rodkin, Inc.

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05-2714 - Laboratory Characterization and Empirical Prediction of Dynamic Modulus of Superpave Mixtures
Session 813
ABSTRACT The Dynamic Modulus |E*| test has been recommended by the National Cooperative Highway Research Program (NCHRP) Project 9-19 to be one of the Simple Performance Tests (SPTs) for performance prediction of asphalt concrete mixtures. This paper presents the results of a comprehensive collaboration study of dynamic modulus testing between two laboratories using two 25-mm Superpave mixtures. Multiple temperature and frequency sweeps were used in the testing. The sensitivity and repeatability of dynamic modulus test results were evaluated based on the test results measured from two laboratories. In addition, two currently most popular dynamic modulus prediction models: Hirsch and Witczak’s models, were employed in this study to predict the dynamic modulus of the two Superpave mixtures considered. The results of this study indicated that the dynamic modulus test generally can have a test variability in terms of the percent coefficient of variation as high as 20 percent among duplicate samples of a mixture. The dynamic modulus values of an asphalt mixture seemed to be sensitive to binder contents in the mixture. At high rutting temperature, both the rutting parameter, |E*|/sinö, and laboratory Hamburg rut tests can predict the rutting potentials of the two mixtures considered in this study consistently. In addition, the variability of dynamic modulus results between two laboratories can be higher than 20 percent. Finally, it was found that both the Witczak’s and the Hirsch models can predict the dynamic modulus values from mixtures properties within a reasonable reliability
     Louay N. Mohammad, Louisiana State University, louaym@lsu.edu
     Zhong  Wu, Louisiana Transportation Research Center
     Leslie Myers McCarthy, Villanova University
     Zhang  Zhongie, Louisiana State University
     Christopher David Abadie, Louisiana Department of Transportation and Development

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05-2725 - Refinement of the Hot-Mix Asphalt Ignition Method for High-Loss Aggregates
Session 473
This study evaluated four methodologies for determining the asphalt content of mixtures containing high loss aggregates in the ignition furnace. The methodologies tested were the standard method using the Thermolyne furnace (control), the Troxler NTO Infrared furnace, the Ontario Method and a Tempyrox glass cleaning oven. Six aggregate sources with high ignition furnace aggregate corrections were obtained from around the country: four dolomites, basalt and a serpentine/chlorite. Calibration factors were determined for each method at optimum asphalt content. Additional samples were then tested at optimum plus 0.5 percent asphalt content and the measured asphalt content calculated using the correction factor determined for that method/aggregate source. The Tempyrox Pyro-Clean furnace, commonly used for cleaning laboratory glassware, produced the lowest aggregate correction factors. The standard method and the Ontario method, both using the Thermolyne ignition furnace produced the smallest bias or error in measured asphalt content. The standard deviation of the corrected asphalt contents for these high loss sources was higher than the within-lab standard deviation reported for AASHTO T308. The only exception was the Alabama source using the standard method. The Ontario Method and Tempyrox Oven generally reduced the variability of asphalt content measurements for high loss aggregates. None of the methods evaluated statistically reduced aggregate breakdown on the NMAS and 4.75 mm sieves. The Ontario method significantly reduced, but did not eliminate aggregate breakdown on the 0.075 mm sieve. The Ontario method is the best method for immediate implementation for determining the asphalt content by the ignition method for high loss aggregates.
     Graham Craft Hurley, Advanced Materials Services, LLC, Graham@amsllc.us
     Brian D. Prowell, Advanced Materials Services, LLC

Concrete Materials

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05-0031 - Mitigating Transverse Cracking in Concrete Bridge Decks
Session 672
Increased transverse cracking has been reported in newly constructed concrete bridge decks in recent years. This is a concern since cracks can cause bar corrosion and concrete deterioration, resulting in decreased service life. This paper presents a summary of the results of investigations conducted by Wilbur Smith Associates for Pennsylvania Department of Transportation (1,2,3,4) to determine the cause of transverse cracking and methods to minimize transverse cracking. The results indicated that thermal shrinkage and drying shrinkage of concrete have a significant role in formation of transverse cracks. Accordingly, practical design and construction procedures were recommended to mitigate formations of transverse cracking in newly constructed bridge decks.
     Khossrow N/A Babaei, A. Morton Thomas & Associates, Inc., kbabaei@amtengineering.com

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05-0162 - Tennessee Evaluation of New Maturity Technology: Laboratory Investigation
Session 508
A project was conducted to evaluate the ability of new maturity technology to predict compressive strength development of Tennessee rigid pavements. The information generated in the project will assist the Tennessee Department of Transportation (TDOT) in making a decision on allowing the new maturity technology to be used in lieu of cylinder compressive strength results for opening new PCC pavements to traffic. In the laboratory portion of the evaluation, one-hundred-twenty (4 groups of 30 each) 6- by 12-inch (152- by 305-mm) cylinders cured at different temperatures were used to validate the maturity relationship over the range of TDOT Portland Cement Concrete (PCC) temperature specifications for curing. The difference between compressive strengths of 6- by 12-inch (152- by 305-mm) cylinders cured in the laboratory at the same maturity index for curing temperatures between 45 and 90°F (7 and 32°C) is in the range of 3.8 to 12.5 percent for maturity indices of 2,400 to 22,000°C-hours. At lower maturity indices, the compressive strength difference in percent was much greater (29.7 to 60.7).
     Lewis Keith Crouch, Tennessee Technological University, lcrouch@tntech.edu

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05-0598 - Properties of Crumb Rubber Concrete
Session 412
Crumb rubber is a material produced by shredding and commutating used tires. There is no doubt that the increasing piles of tires create environmental concerns. The long term goal of this research is to find means to dispose of the crumb rubber in Portland cement concrete and still provide a final product with good engineering properties. The Arizona Department of Transportation and Arizona State University initiated several crumb rubber concrete (CRC) test sections through out Arizona over the past few years. Laboratory tests were conducted to support the knowledge learned in the field, and enhance the understanding of CRC material properties. Concrete laboratory tests included compressive, flexural, indirect tensile strength, thermal coefficient of expansion, and microscopic matrix analysis. The unit weight, compressive and flexural strength decreased as the rubber content in the mix increased. Further investigative efforts determined that the entrapped air, causing excessive reductions in compressive strength, could be substantially reduced by adding a de-airing agent. Higher tensile strains at failure observed from the tests were indicative of more ductile, energy absorbent, mix behavior. The coefficient of thermal expansion tests results indicated that the CRC are more resistant to thermal changes. The CRC specimens tested remained intact after failure, and did not shatter compared to a conventional mix. Such behavior may be beneficial for a structure that requires good impact resistance properties. If no special considerations are made to maintain higher strength values, the use of CRC mixes are recommended in places where high strength concrete is not required.
     Kamil Elias Kaloush, Arizona State University, kaloush@asu.edu
     George  Way, Scottsdale, Arizona
     Han  Zhu, Tian Jin University

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05-0706 - Time-Dependent Compressive Strength Development in Florida Concrete
Session 452
The Florida Department of Transportation (FDOT) specifications contain time dependent concrete compressive strength equations to predict equivalent 28-day strengths based on core strengths at other times. The FDOT models are many years old, and are not likely to represent current FDOT concrete mixes. Compressive strength testing using a typical FDOT concrete mix design at various ages was performed herein in order to develop appropriate strength variation models. Variation in the mixes was achieved through substitution of cement types, slag for fly ash, and coarse aggregate type. Selected existing models from the literature were examined for statistical goodness-of-fit to the test data. The best performing models relating the 28-day compressive strength to strengths at other time periods were recommended.
     Nur  Yazdani P.E., University of Texas, Arlington
     Bryant  McKinnie, No Organization
     Saif Abdullah Haroon, SAIFUL/BOUQUET STRUCTURAL ENGINEERS, INC., sharoon@sbise.com

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05-0713 - Aggregate-Based Modulus of Elasticity for Florida Concrete
Session 412
The current Florida Department of Transportation (FDOT) concrete modulus of elasticity ('E') empirical model is a function of concrete compressive strength and unit weight. Recent testing shows that this model consistently underestimates the 'E' for FDOT concrete. This underestimation may lead to construction problems caused by over-prediction of camber and deflection of concrete structural members. 'E' values were experimentally determined at various concrete ages for the typical concrete mix used in FDOT projects. Regression analyses were used to find the best fit 'E' models to the generated data, and such models were compared with existing 'E' models from the literature. It was found that the aggregate type and specific gravity plays a significant role in influencing concrete 'E'. Best fit 'E' models for FDOT concrete together with suggested modification factors for various aggregate types were recommended.
     Nur  Yazdani P.E., University of Texas, Arlington
     Bryant  McKinnie, No Organization
     Saif Abdullah Haroon, SAIFUL/BOUQUET STRUCTURAL ENGINEERS, INC., sharoon@sbise.com

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05-0756 - Performance and Uniformity of Self-Compacting Concrete
Session 211
Self-compacting concrete (SCC) is an emerging concrete type where its cohesive yet flowable consistency help securing proper placement with good homogeneity. Such concrete can be achieved by adjusting mix proportions and incorporating adequate admixtures such as the viscosity modifying (VM) admixtures with no vibration. Yet, the impact of the mix proportions and the role played by the VM as opposed to superplasticizers (SP) admixtures is not fully understood. There also seems to be no unique means for assessment of such concrete and the correlation between various tests needs further work. This study aims at achieving better understanding of the influence of mix proportions on the properties of SCC. Twenty-six mixtures were prepared with various w/c, fine-to coarse aggregate ratio and admixture dosages. Fresh concrete tests including slump flow, L-box, U-box and hardened concrete tests including hardened density, compressive and flexural strength as well as the Rebound Hammer were performed. The uniformity of SCC properties along column specimens was examined. The results reveal that adjusting mix proportions has a major impact on fresh and hardened properties of SCC. The fresh concrete tests were found to correlate well with one another and the SCC strength was comparable to that of reference concrete made with mechanical vibration. Yet, SCC exhibited remarkable uniformity of properties within the components examined. This work suggests that future studies performed on SCC should involve large-sized specimens in which concrete properties are evaluated in various locations.
     Mohamed Nagib Abou-Zeid, American University in Cairo, Egypt, mnagiba@aucegypt.edu
     Mohamed Samir Roushdy, Al-Kharafi Contracting W.L.L., Kuwait

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05-0861 - Effect of Density and Mixture Proportions on Freeze-Thaw Durability of Roller-Compacted Concrete Pavement
Session 702
Roller-compacted concrete (RCC) is widely used for industrial and heavy duty pavements. It is an economical and durable material for paving and other applications. RCC has relatively high strength and density. Although the strength of RCC has been thoroughly investigated, the freeze-thaw durability of RCC remains a topic of contention. RCC has often performed well in harsh field environments, but it often fails laboratory freeze-thaw durability testing. In this study, 24 specimens were fabricated for freeze-thaw durability testing using a gyratory compactor. Study variables were degree of compaction, amount of water, and water/cement (w/c) ratio (and hence, also, amount of cement). Specimens replicated typical RCC pavement and dam construction. The RCC specimens were subjected to up to 300 cycles of rapid freezing and thawing, and were tested for fundamental transverse frequency and mass loss. Due to the low aspect ratio of the specimens, fundamental transverse frequency testing was not reliable. Several specimens completed the 300 cycles with mass loss of less than 10 %. The freeze-thaw durability of RCC was found to be dependent primarily on the amount of cement paste and w/c ratio, and to a lesser extent on degree of compaction.
     Norbert Joseph Delatte, Cleveland State University, n.delatte@csuohio.edu
     Chris  Storey, University of Alabama, Birmingham

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05-1517 - Formwork Pressure of Self-Consolidating Concrete in Tall Wall Field Applications
Session 211
The growing interest in the use of self-consolidating concrete (SCC) for a wide variety of structural applications has initiated a reexamination of its properties and current construction practices, and how they compare to conventional concrete. One property of interest is the formwork pressure of SCC and how it relates to conventional concrete. This work presents the results from three tall walls (28, 21.7 and 13 ft. tall) cast slowly with SCC, and a 10.6 ft. high column poured quickly using the same concrete as one of the walls. The research demonstrates that pressure of SCC against formwork drops very quickly just after the concrete material is placed. Measurements from the walls poured slowly show that the maximum recorded pressure falls far below the hydrostatic pressure and is closely related to the pouring rate. The experiments also reveal that formwork pressure exerted by SCC can be revitalized if vibrated, even if stiffening is already in progress
     Fernando  Tejeda-Dominguez, University of Illinois, Urbana-Champaign, tejedado@uiuc.edu
     David A. Lange, University of Illinois, Urbana-Champaign
     Matthew D. D'Ambrosia, University of Illinois, Urbana-Champaign

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05-1927 - Comparison of Concrete Strength Development Between Bridge Deck Cores and Concrete Test Cylinders Under Varying Curing Durations
Session 452
With ever increasing traffic flow in urban areas, lane, road, and/or bridge closures have become an inconvenience to road users. As a result, there continues to be pressure to open concrete pavements and bridge decks to full traffic loads earlier. However, the built structure must also remain functional (i.e. durable). Durability of concrete bridge decks has long been associated with good concrete mix designs and adequate curing durations. To better assess the potential of reduced required curing times for bridge decks, the Texas Department of Transportation (TxDOT) has collaborated with Texas Tech University in a research project entitled: “Effects of Wet Mat Curing and Earlier Loading on Long-Term Durability of Bridge Decks.” In addition to required curing times, many bridge decks and concrete pavements across the country are opened to traffic once a desired compressive strength is achieved from a representative field-cast 6-inch diameter test cylinder (1). Thus, concrete strength gain and required curing duration are major factors in determining the minimal amount of time before a concrete deck or pavement can be put into use. The emphasis of this paper is to present a comparison on the effects that different wet mat curing durations have on concrete strength development – both on actual 4-inch diameter bridge deck cores and on 6-inch diameter test cylinders. This comparison is considered a first step in determining the minimum required curing duration for a bridge deck. Additional durability tests are required before allowance to earlier bridge deck loads will be granted.
     Hector  Garcia, Texas Tech University
     Randal Scott Phelan PhD, PE, SE, Buckland & Taylor, scph@b-t.com
     Sanjaya P. Senadheera, Texas Tech University
     Kevin  Pruski P.E., Texas Department of Transportation

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05-2018 - Modulus and Thickness Evaluation for Concrete Pavement by Love- and SH-Wave Measurements
Session 568
Wave propagation techniques have been applied to make reliable measurements of the in situ conditions of Portland cement concrete pavements. The SASW method and the impact-echo method are typical techniques in this category. These methods, based on Rayleigh waves and P waves, respectively, may provide an evaluation of modulus and thickness of the concrete slab, but its accuracy and reliability is dependent upon the factors such as boundary conditions, measurement configuration and assumed Poisson¡¯s ratio. In this research, a new seismic technique is proposed and evaluated for the nondestructive evaluation of modulus and thickness of a concrete pavement. The proposed seismic technique is based on Love and SH waves, unlike the conventional seismic techniques based on Rayleigh and P waves. Love and SH waves are beneficial in that Love-wave velocity is equivalent to the shear-wave velocity of the surface layer and SH waves are not subject to mode conversion after multiple reflections. The proposed method is substantiated by the numerical simulation of the stress-wave propagation based on the forward modeling theory. Case studies are presented to verify the feasibility of the proposed approach. The SASW and the impact-echo testing were performed at the CRCP of the US highway 183 and US 59 in Texas. Love and SH waves were employed in the measurements together with Rayleigh and P waves for comparison. The resonance measurements of the cores taken from the pavement proved that the proposed method can evaluate modulus and thickness of the concrete slab reliably and accurately.
     Sung-Ho  Joh, Chung-Ang University, South Korea, shjoh@cau.ac.kr

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05-2349 - Workability Assessment of Low-Slump Concrete
Session 412
The slump test is the most widely used test for measuring concrete workability. Nevertheless, it is not an adequate tool for assessing “low-slump” concrete workability. In other to better quantify the workability of such concretes, U.S. Army Corps of Engineers (USACE) has developed the Vibrating Slope Apparatus (VSA). This study presents an evaluation of Vibrating Slope Apparatus (VSA). Two test methods were investigated: the original test method created by USACE, i.e., concrete mass loss under vibration as a function of time, and a method involving initial energy and time/energy to concrete movement.
     Jussara  Tanesi Ph.D., SES Group & Associates, LLC, jussara.tanesi.ctr@dot.gov

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05-2460 - Influence of Cement Composition on Expansions Observed in Standard and Modified ASTM C1260 Test Procedures
Session 510
This paper presents the results of a lab study conducted to determine the influence of cement composition on the expansions observed in standard and modified ASTM C 1260 tests. Also, the effectiveness of selected mitigation measures for alkali-silica reactivity using a modified ASTM C 1260 test was studied. Two different cements with substantially different alkali levels were used in combination with a Class F fly ash and a Class C fly ash. Results obtained from testing 89 different sources of fine aggregate were analyzed. The results from this study indicate that cement composition has a distinct influence on the expansion levels observed in the ASTM C 1260 study. For a majority of aggregates tested in this study (88%), the use of a specific cement, that is low in its alkali content, resulted in higher expansion than a cement that had relatively higher alkali content, regardless of the level of reactivity of the aggregate in the standard ASTM C 1260 tests. Class F fly ash was found to be more effective compared to Class C fly ash in reducing the expansions in the modified ASTM C 1260 tests. However, the cement used in the mixture influenced the percent reduction in expansion offered by both Class F fly ash and Class C fly ash. The use of low-alkali cement with Class F and Class C fly ashes yielded larger reductions in percent expansion in the modified ASTM C 1260 test. Keywords: ASTM C 1260 test, alkali-silica reaction, ASR, fly ash, mitigation measures
     Prasada Rao  Rangaraju, Clemson University, prangar@clemson.edu
     Ketan Ramakant Sompura, Clemson University

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05-2602 - Properties of Latex-Modified Concrete Under Different Curing Conditions
Session 508
For many decades, Latex-Modified Concrete (LMC) overlays have been successfully used in the United State and have provided protection for many bridge decks and their steel reinforcement. LMC remains one of the most desirable rehabilitation materials for concrete bridge decks because it is easier to place and requires minimal curing. Nonetheless, as the case with any other cement-based material, LMC overlays are sustable to plastic shrinkage and delamination, which are often solved by proper curing and surface preparation. Despite their success stories, many questions have been raised regarding the best practices for placing LMC overlays and the proper curing and placement conditions. The current curing practice for LMC in most States simply follows the recommendation by the latex manufacturer because there is very little information on the proper curing methods. There is a need to establish detailed technical specifications regarding the proper curing and placement conditions that will provide durable LMC overlays. This paper provides an in-depth study of the effect of curing methods on the mechanical properties and durability of LMC. Four different curing methods were studied: 1) dry curing, 2) 3 days moist curing, 3) 7 days moist curing, and 4) compound curing. Results show that extending the moist curing duration to 7 days moist curing significantly improves both the mechanical properties and durability of LMC.
     Hani H. Nassif, Rutgers University, nassif@rutgers.edu
     Nakin  Suksawang, Florida Institute of Technology
     Amer  Mohammed, Rutgers University

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05-2637 - Effect of Curing Temperature on Hardened Concrete Properties: Mixtures of Ground Granulated Blast Furnace Slag, Fly Ash, or a Combination of Both
Session 508
Often concrete is not mixed or placed in ideal conditions. Particularly in winter or summer months, the fresh concrete temperature is quite different than concrete mixed in laboratory conditions. This paper examines the influence of supplementary cementitious materials on the strength development of concrete subjected to different curing regimens. The supplementary cementitious materials used in the research program were ground granulated blast furnace slag (GGBFS), fly ash, and a combination of both materials. The three curing regimens employed were; hot weather curing, standard curing, and cold weather curing. Test results show that the addition of GGBFS at a relatively low replacement rate can improve the hardened properties for each curing regimens. This improvement was noticeable not only at later ages, but at early ages too. Mixtures containing both materials (GGBFS and fly ash) performed as well and in most cases better than mixtures containing only portland cement at all curing regimens.
     W. Micah Hale, University of Arkansas, Fayetteville, micah@uark.edu
     Thomas D. Bush, Frankfurt Short Bruza Associates
     Bruce W. Russell, Oklahoma State University
     Seamus F. Freyne Ph.D., Manhattan College

Construction

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05-0025 - Reliability of Piezocone Penetration Test Methods for Estimating the Coefficient of Consolidation of Cohesive Soils
Session 260
This paper presents the evaluation of the current PCPT interpretation methods for their capability to reasonably estimate the vertical coefficient of consolidation (cv) of cohesive soils utilizing the piezocone dissipation tests. The PCPT methods included in this evaluation are: Teh and Houlsby (1), Levadoux and Baligh (2), Robertson and Campanella (3), Teh (4), Senneset et al. (5) (two methods), and Jones and Rust (6). To achieve this goal, six sites in Louisiana were selected for this study. In each site, in-situ PCPT tests were performed and soundings of cone tip resistance (qc), sleeve friction (fs), and pore pressures at different locations (u1 and u2) were recorded. Piezocone dissipation tests were also conducted at different penetration depths. High quality shelby tube samples were collected close to the PCPT tests and used to carry out a comprehensive laboratory-testing program. The vertical coefficient of consolidation (cv), predicted using the different interpretation methods, were compared with the reference values determined from the oedometer laboratory tests. The results of this research study showed that the Teh and Houlsby (1) and Teh (4) methods can estimate cv better than the other prediction methods.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens

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05-0037 - Application of Dynamic Cone Penetrometer in Pavement Construction Control
Session 260
This paper presents the results of a comprehensive testing program that was conducted to evaluate the potential use of the Dynamic Cone Pentrometer (DCP) device in the quality control/quality assurance (QC/QA) procedure during the construction of pavement layers and embankments. The laboratory tests were conducted on different materials prepared inside two test boxes 1.5m x 0.9m x 0.9m (5ft x 3ft x 3ft) located at Louisiana Transportation Research Center (LTRC). The field tests were conducted on different highway sections in Louisiana. In addition, nine test sections were constructed and tested at the Pavement Research facility (PRF) site of the LTRC. In all laboratory and field tests, DCP tests were conducted in companion with the Plate Load Test (PLT). In addition, Falling Weight Deflectometer (FWD) tests were conducted on the field sections. CBR laboratory tests were also performed on samples collected from the tested sections. Regression analysis was carried out on the collected data to correlate the DCP-PR with the three reference tests used in this study (PLT, FWD and CBR). Further field tests were conducted to verify the developed regression models. The results of these tests indicated that the developed models yielded good predictions of the measured FWD moduli and CBR values. This suggests that these models can be used to reliably evaluate the stiffness/strength of different pavement materials.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens
     Khalid A. Alshibli, University of Tennessee, Knoxville
     Ekram  Seyman, Louisiana State University

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05-0242 - Precast Bridge Deck Solutions for Rapid Rehabilitation of Truss Bridge
Session 706
ABSTRACT The Bridge and Structures Office completed the design for the Lewis and Clark Bridge deck replacement project in October of 2002. This historic bridge, designed by Joseph B. Strauss of Golden Gate Bridge fame, was built in 1930. It spans the Columbia River between Longview, Washington and Rainier, Oregon. The bridge consists of a 2,720-foot (829m) main through-truss section, a 927-foot (283m) deck truss section on the Oregon side, and a 168-foot (51m) deck truss and a 1,507 foot (459m) 12 span rolled-beam section on the Washington side. The bridge could only be closed to traffic at night from 9:30 P.M. to 5:30 A.M. during construction due to traffic constraints. Night closures were limited to 120 days and single-lane closures were limited to 200 days. The WSDOT Bridge Office designed a method to replace the existing concrete deck on the main through-truss and deck trusses, and for widening the existing deck on the rolled beam spans, using precast concrete deck panels. A total of 103 precast panels with a constant width of 36 feet (11.97m) and variable lengths of 25 to 45 feet (7.62 to 13.72m) were placed on the trusses. For the rolled-beam spans 46 precast panels with a constant width of 4 feet (1.22m) and variable lengths of 58 to 70 feet (17.68 to 21.34m) were placed. Construction is complete as of this date. This paper will examine in depth the design, construction and lifting operations involved with the replacement of the existing bridge deck with precast full width panels. The total cost of this project was $27 million.
     Munindra  Talukdar, Washington State Department of Transportation, talukdm@wsdot.wa.gov

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05-0281 - Simplified Laboratory Assessment of Subgrade Performance Parameters for Mechanistic Design of Pavement Foundations
Session 260
With the increasing agenda for sustainability, the UK is attempting to move away from the empirical design of pavement foundations to develop a performance specification approach to facilitate analytical design. For analytical design the measurement of the subgrade performance parameters of stiffness and resistance to permanent deformation are required. These parameters ideally need to be assessed concurrently under loading and environmental conditions similar to those the materials will experience in the field. To date, measurement of these parameters is largely confined to research laboratories using cyclic triaxial testing with on sample strain measurement. This apparatus is considered too complicated for routine commercial use, hence this potentially limits the implementation of laboratory performance evaluation for pavement foundation design. A previous program of cyclic triaxial testing on clay subgrades indicated a series of useful correlations between strength and permanent deformation behavior (via a threshold stress), and material stiffness at this threshold. This paper reviews the previous work and utilizing these correlations presents data from tests on three different clay materials performed to develop simplified equipment and procedures for the routine measurement of the required design parameters. It is shown that simple monotonic tests can measure a subgrade stiffness for a simplified performance based design. It re-evaluates the previous data (in the light of the recent work) to show a boundary correlation that may allow a shear strength based parameter to control (in design) the onset of permanent deformation, and details how long-term subgrade water content changes can be accommodated.
     Matthew William Frost, Loughborough University, United Kingdom, m.w.frost@lboro.ac.uk
     Paul  Edwards, Scott Wilson Pavement Engineering Ltd., United Kingdom
     Paul Richard Fleming, Loughborough University, United Kingdom
     Stuart John Arnold, Ramboll Whitbybird

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05-0727 - Design and Construction of a Full-Width, Full-Depth Precast Concrete Deck Slab on Steel Girder Bridge
Session 706
The existing West Sandusky Bridge over I-75, located in Findlay, Ohio, is being replaced with a new 170’ span hybrid steel plate girder bridge with concrete deck. In order to minimize closure times on West Sandusky Street, and reduce traffic delays on I-75 during construction, full-width, full-depth precast concrete deck panels will be used for the construction of the bridge deck. During preliminary design, a variety of alternate precast deck slab designs were considered, and a full-width, full-depth precast deck slab was selected as the preferred alternative. The precast deck panels are post-tensioned both longitudinally and transversely to minimize cracking and improve durability. The deck panels are constructed with shear stud pockets to allow for the installation of shear studs after erection and post-tensioning. During detail design, a finite element analysis of the bridge deck was carried out to determine the required level of prestressing in the deck. A time dependent analysis was subsequently carried out to determine the long term creep effects and post-tensioning losses, including the effects of restraint from the steel girders. A sensitivity analysis was carried out to determine the optimum curing time required prior to stressing the longitudinal post-tensioning tendons and grouting the shear pockets. The steel plate girders were designed for the additional long term creep effects due to the post-tensioning of the deck, which imposed additional axial loads and moments on the steel girders.
     Alex Thomas Harrison, CH2M Hill, aharris1@ch2m.com
     Norman David LeBlanc, Totten Sims Hubicki Associates

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05-0903 - Development of a Test Method to Measure the Quality of Milling Operations in Asphalt Pavements
Session 527
Cold milling operations have been utilized for over two decades in Indiana but little attention was given to the “quality” of the operations. Several alternatives for evaluating surface macrotexture were considered as a quality measure. ASTM E 965-96 was selected as the best existing procedure on which to base evaluation of milled surfaces. The Indiana DOT developed test method ITM 812-03T to make the ASTM procedures workable for milled surfaces. The initial quality of Hot Mix Asphalt (HMA) construction directly affects the return on investment with the long-term performance and the service life of a transportation facility. The initial quality of construction is directly dependent upon the quality of the aggregates and binders and the production and laydown operations. Construction factors affect the initial quality including surface preparation procedures that is the removal of distressed materials (cold milling) to develop a stable working platform on which Hot Mix Asphalt materials can be placed. The Indiana Hot Mix Asphalt contractors were experiencing numerous problems meeting the volumetric and density quality requirements on highway construction projects. A significant number of HMA mixtures were either being accepted with partial payment or replaced prior to being accepted. Investigation of the problem included observing the contractor’s Certified HMA Plant Production operations, mixture components (i.e., aggregates, binders, etc), mixture transportation, laydown and compaction, and also mixture sampling procedures. It was discovered that more problems existed when cold milling of the existing surface was included in the project. A solution to the noted issues resulted in the development of improved milling design and construction requirements, which includes quality measurements techniques for the milling operations. Key Words: Cold Milling, HMA, Hot Mix Asphalt, Quality, Macrotexture, Milling
     Victor Lee Gallivan, Gallivan Consulting, Inc., Lee@GallivanConsultingInc.com
     Joseph F. Gundersen, Indiana Department of Transportation

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05-0937 - Improving Construction Communication
Session 608
This study examines data collected from ADOT customers during the State Route 51 (SR 51) project. During the $75 million project, approximately 10 miles of SR 51 between Interstate 10 and State Route 101 were renovated to include new high occupancy vehicle (HOV) lanes and rubberized asphalt. Communication was measured by customer (e.g., motorists as well as local residents and businesses) utilization of four direct communication channels (e.g., construction signage) and four indirect communication channels (e.g., television programming). Satisfaction was measured by a composite score based on customer satisfaction with traffic, dust, noise, signage, and information during the construction process. Almost all respondents relied upon at least one channel for construction communication and almost 80% of respondents reported using between one and three channels. The most frequently utilized channel was construction signs (55.9%) and the least frequently utilized channel was e-mail alerts (1.5%). Less than 4% of the respondents did not utilize any communication channel. Direct communication channels resulted in higher customer satisfaction than did indirect communication channels. Construction bulletins contributed the most to customer satisfaction, followed by the project web site. Neither television nor radio contributed to customer satisfaction. As sources of project communication, neighbors and friends had a strong but negative effect on customer satisfaction.
     John  Semmens, Arizona Department of Transportation, jsemmens@azdot.gov
     Robert S Done Ph.D., University of Arizona

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05-1186 - Experimental Investigations of the Effects of Multiple Heat Straightening Repair on the Structural Properties of Bridge Steels
Session 479
Experimental investigations were conducted to evaluate the effects of multiple damage-heat straightening repair cycles, i.e., multiple cycles of damage followed by heat straightening repair on the fundamental structural properties of typical bridge steels ASTM A36, A588, and A7. The damage and repair parameters considered in the study are the damage strain , the restraining stress , and number of multiple damage-repair cycles (Nr). The effects of these parameters are evaluated on the following structural properties: (a) elastic modulus, (b) yield stress, (c) ultimate stress, (d) percent elongation, (e) surface hardness, and (e) fracture toughness. A total of seventy-five laboratory-scale specimens made from A36, A588, or A7 steel were subjected to multiple damage-repair cycles, and their effects on the structural properties were evaluated. The results from the experimental investigations indicate that multiple damage-repair cycles have a small influence (± 15%) on the elastic modulus, yield stress, and ultimate stress. However, the percent elongation and fracture toughness of the damaged-repaired steel are influenced significantly. Based on reductions in the percent elongation and fracture toughness, it is recommended that A7 and A36 steel be limited to three damage-heat straightening repair cycles. A588 steel can be subjected up to five damage-heat straightening repair cycles.
     Keith Joseph Kowalkowski Ph.D, Ruby and Associates, P.C., kowalkowski@rubyusa.com
     Amit Hariom Varma, Purdue University

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05-1194 - Revising Specification Limits of Existing Quality Assurance Specification
Session 364
The results of a study to evaluate the existing SCDOT hot mix asphalt Quality Assurance specification are presented. When the existing specification was developed, assumed values were used for the standard deviations needed to establish the specification limits. Acceptance test results from 39 different projects were analyzed to determine standard deviation values that were being obtained for asphalt content, air voids, VMA, and density. For each project, standard deviation values were calculated for each lot, and these were then pooled to obtain a typical value for the project. The project values were then used to establish a typical process standard deviation value for each of the four acceptance characteristics. All of these standard deviation values proved to be smaller than those initially assumed, and resulted in the SCDOT narrowing the specification limits for each of the acceptance characteristics. The project standard deviation values justified that these changes were made to reflect the actual variability that was present, and not simply to tighten the specifications.
     James L. Burati Jr, Clemson University, jlbrt@clemson.edu

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05-1453 - Initial Ride Quality of Hot-Mix Asphalt Pavements
Session 527
Ride quality assessed with an inertial profiler on flexible pavement was used to provide initial information on the following key issues: repeatability associated with IRI values for a wide range of hot mix asphalt (HMA) material variables, timing of acceptance testing for initial ride quality, IRI changes with type of roadway, influence of stops and starts in the paving operation on ride quality, identification of “bump”, and effect of grinding on IRI. IRI was calculated for 25-foot intervals instead of the standard 0.1 mi (528 feet) for all testing in order to highlight local anomalies such as bumps due to paving stoppages. Results indicate that the standard deviation of three replicate passes with an inertial profiler is 5 in/mi (includes 46 HMA mixes). IRI measurements with time suggest that initial acceptance testing can be conducted within 7 days, thereby allowing more flexibility in scheduling by the agency. Limited traffic also slightly reduces the IRI values, which is to the contractor’s advantage. IRI values are defined for two-lane county roads, medium to high traffic facilities. Separate IRI ranges are suggested for each of these categories based on the type of HMA construction: new, repair and overlay, and mill and overlay. These ranges are set for best and good practices (continuous paving, no stoppages; consistent supply of trucks, very short stops). IRI values greater than 125 in/mi in any given 25-foot interval indicate a bump; bumps can be ground so that these areas have IRI values of less than 100 in/mi.
     Mary  Stroup-Gardiner, Gardiner Technical Services, LLC, marystroupgardiner@outlook.com
     Alan  Carter, Universite du Quebec, Canada
     Priyabrata (Thomas)  Das, Auburn University
     Brian  Bowman, Auburn University

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05-1518 - Investigation of the CoreLok for Maximum, Aggregate, and Bulk Specific Gravity Tests
Session 473
The Florida Department of Transportation uses long established test procedures to determine the maximum specific gravity (Gmm) and bulk specific gravity (Gmb) of asphalt mixtures and bulk specific gravity (Gsb) of aggregates. The CoreLok, a vacuum-sealing device that can be used to determine these properties, was evaluated by the Department for these four test procedures. With respect to the Gmm test procedure, for mixtures containing non-absorptive granites, the CoreLok determined equivalent results compared to the Department’s test procedure. However, for mixtures containing absorptive limestones, the CoreLok determined higher Gmm values compared to the Department’s test procedure. The apparent reason for the discrepancy is because the CoreLok does not determine a saturated surface-dry condition of the sample. With respect to the aggregate specific gravity test procedures, the CoreLok provided equivalent test results to the Department’s test procedure for the non-absorptive fine aggregates only. For the absorptive fine aggregates and all of the coarse aggregates, the CoreLok determined significantly different Gsb test results compared to the Department’s test procedures. The CoreLok may be suitable for determining Gmb for coarse graded compacted specimens with high porosity and air voids. There are concerns with the accuracy of the CoreLok results due to the bridging effect of the plastic bag over the large surface voids and due to the CoreLok’s significant underestimation of the specific gravity of a solid aluminum cylinder.
     Gregory Allen Sholar, Florida Department of Transportation, gregory.sholar@dot.state.fl.us
     Gale C. Page, Florida Department of Transportation
     James A. Musselman, Florida Department of Transportation
     Patrick B Upshaw, Florida Department of Transportation
     Howard L. Moseley, Florida Department of Transportation

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05-1816 - International Construction Management Practices: Report of FHWA-AASHTO Scan Tour
Session 565
In May of 2004, a U.S. panel of federal, state, and private sector professionals traveled to Canada and Europe to learn from their significant experience by conducting a scan of “Construction Management Practices for Effective Project Delivery, Contract Compliance and Quality Assurance.” The purpose of this research was to review and document international policies, practices and technologies for potential application in the U.S. The team conducted meetings and site visits with government agencies, academia, and private sector organizations involved in construction management efforts. The research team observed construction management methods that promote alignment of team goals, integrated use of risk analysis techniques, strategic use of alternative delivery methods, procurement systems that set a framework for success, contract payment methods that support alignment and trust, a delegation of traditional highway agency functions to promote efficiency, a philosophy of network management, and a greater partnership between public and private agencies. The team is offering a challenge to public and private highway construction professionals to change the current construction management practices that create adversarial relationships. The team recommends construction management practices that better align project team goals to customer goals. Specifically, the team is recommending that state develop rigorous risk assessment and allocation techniques, strategically apply alternative delivery methods, enhance qualification rating processes, use qualifications in procurement, apply alternate bids/designs in procurement, conduct more detailed pre-proposal meetings, apply more contractor quality management, use appropriate alternative payment methods, and ultimately work toward more warranties and life cycle responsibility in projects.
     Keith R. Molenaar PhD, University of Colorado, Boulder, molenaar@colorado.edu

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05-2128 - Risks with Multiple Pay Factor Acceptance Plans
Session 364
It is rare that a state highway agency (SHA) uses only a single quality characteristic to determine the pay factor for a lot. This paper deals with two specific types of risk associated with the use of multiple quality characteristics: remove and replace provisions; and the effect on pay factor determination if the quality characteristics are correlated. First, computer simulation studies showed that typical acceptance plan provisions that call for lot removal and replacement at a given quality level, such as 60 PWL or 50 PWL, can place much greater risk on the contractor when they apply to multiple characteristics. An approach to correct his problem was developed. Next, a total of 1,742 sets of asphalt content (AC), air voids (AV), and VMA test results were analyzed for correlations. VMA was shown to be positively correlated with both AV and AC. Additional simulation studies showed that while this correlation does not affect the long-term average pay factor for a lot, it will increase the variability in the individual lot composite pay factors. The positive correlation also has the effect of increasing the weighting of AV and AC in the composite pay equation. The use of multiple quality characteristics for determining the pay factor for a lot introduces sources of risk that are not present when only one characteristic is used. Any SHA that uses multiple pay factors should consider performing the types of remove and replace and correlation analyses presented in this paper.
     James L. Burati Jr, Clemson University, jlbrt@clemson.edu

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05-2612 - Evaluation of Dowel Bars Installed in Airfield Concrete Pavement Construction Joints by Using Plastic Sleeves
Session 509
This paper presents the results of evaluation of the effectiveness of a new innovative process for installing dowel bars in construction joints without drilling. The procedure involves inserting plastic sleeves with the same outside dimensions as the drilled holes into plastic concrete to create the holes for the dowel bar installation, rather than drilling. The plastic sleeves are later removed and the dowel bars are inserted in the holes left behind. To ensure that the new technique for dowel bar installation is free of any deleterious effects, the technique must be shown to produce dowel bar alignments that are comparable to the bars installed using the conventional method without causing any other problems. A field testing was conducted to evaluate the viability of the new technique for installing dowel bars in construction joints. The evaluation is based on the key factors that determine the engineering feasibility of the new procedure, which include dowel bar alignment, consolidation of concrete around the plastic sleeves, and the impact of the insertion techniques on pavement surface profile. The field testing results showed that the plastic sleeves can produce dowel bar alignments that are comparable to or better than the conventional drilling method, without any deleterious effects.
     Hyunhwa Thomas Yu P.E., Federal Highway Administration, tom.yu@dot.gov

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05-2725 - Refinement of the Hot-Mix Asphalt Ignition Method for High-Loss Aggregates
Session 473
This study evaluated four methodologies for determining the asphalt content of mixtures containing high loss aggregates in the ignition furnace. The methodologies tested were the standard method using the Thermolyne furnace (control), the Troxler NTO Infrared furnace, the Ontario Method and a Tempyrox glass cleaning oven. Six aggregate sources with high ignition furnace aggregate corrections were obtained from around the country: four dolomites, basalt and a serpentine/chlorite. Calibration factors were determined for each method at optimum asphalt content. Additional samples were then tested at optimum plus 0.5 percent asphalt content and the measured asphalt content calculated using the correction factor determined for that method/aggregate source. The Tempyrox Pyro-Clean furnace, commonly used for cleaning laboratory glassware, produced the lowest aggregate correction factors. The standard method and the Ontario method, both using the Thermolyne ignition furnace produced the smallest bias or error in measured asphalt content. The standard deviation of the corrected asphalt contents for these high loss sources was higher than the within-lab standard deviation reported for AASHTO T308. The only exception was the Alabama source using the standard method. The Ontario Method and Tempyrox Oven generally reduced the variability of asphalt content measurements for high loss aggregates. None of the methods evaluated statistically reduced aggregate breakdown on the NMAS and 4.75 mm sieves. The Ontario method significantly reduced, but did not eliminate aggregate breakdown on the 0.075 mm sieve. The Ontario method is the best method for immediate implementation for determining the asphalt content by the ignition method for high loss aggregates.
     Graham Craft Hurley, Advanced Materials Services, LLC, Graham@amsllc.us
     Brian D. Prowell, Advanced Materials Services, LLC

Design

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05-0396 - Deception Pass Log Rail in Washington State
Session 215
Washington State Route 20 in northwest Washington passes through the Deception Pass State Park. The Civilian Conservation Corps (CCC) constructed the portion of SR 20 within the park in the mid 1930’s. As part of this work, the CCC constructed a stone masonry bollard and log rail system to delineate the edge of the road and prevent early model vehicles from leaving the roadway (see Figure 2). Due to their age, quality of workmanship, and importance to the surroundings, the bridges and log rails are eligible for the National Register of Historic Places. Previous attempts to replace this rail with a crashworthy system were unsuccessful due to concerns for the aesthetic and historic integrity of the park. A new approach was adopted began with understanding the context of the highway and the concerns of the other stakeholders. In addition, the stakeholders were educated on the safety issues. As a result a solution was developed that was acceptable to all of the stakeholders. The primary solution involved the development of a new barrier that replicated the original log rail. This barrier was crash tested in accordance with the NCHRP Report 350 TL-2 criteria and is available for use in other locations where an aesthetic barrier is desired.
     Richard B Albin, Federal Highway Administration, dick.albin@dot.gov
     Omar W Jepperson, Washington State Department of Transportation
     William Frederick Williams, Texas A&M Transportation Institute
     D. Lance Bullard Jr., Texas A&M Transportation Institute

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05-0785 - Sequential Kinking and Flared Energy-Absorbing End Terminals for Midwest Guardrail System
Session 215
The Midwest Guardrail System (MGS), developed at the Midwest Roadside Safety Facility, was designed to improve the performance of traditional strong-post, W-beam guardrail systems. These improvements include decreasing the potential for rollover with high center-of-gravity vehicles, decreasing the potential for rail rupture at the splice locations, and decreasing the sensitivity of the system to the installation rail height. However, safe guardrail termination options for the MGS must be developed before the system can be implemented on the roadside. Two end terminal designs, the Sequential Kinking Terminal (SKT) and the FLared Energy Absorbing Terminal (FLEAT), were partially re-designed and crash tested in conjunction with the MGS guardrail system according to NCHRP Report No. 350 criteria. The new versions of the terminals were named the SKT-MGS and the FLEAT-MGS in order to designate them for use with the MGS guardrail system. In order to evaluate the performance of the terminals with the MGS system, a series of four full-scale crash tests were conducted. Two redirection tests, NCHRP Report No. 350 test designations 3-34 and 3-35, and two head-on impacts, test designations 3-30 and 3-31, were conducted. The results from the four crash tests conducted were found to meet all relevant safety requirements. The SKT-MGS and FLEAT-MGS end terminals are the first successfully tested end terminals for use with the MGS guardrail system.
     Robert  Bielenberg, University of Nebraska, Lincoln
     John  Rohde, University of Nebraska, Lincoln
     Dean L. Sicking, University of Nebraska, Lincoln
     John D. Reid, University of Nebraska, Lincoln, jreid@unl.edu

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05-1609 - Resilient Modulus Testing on Indiana Subgrade Soils
Session 210
ABSTRACT Resilient modulus has been used for characterizing stress-strain behavior of subgrades in the design of pavements. Recently the Resilient modulus (Mr) testing procedure has been upgraded through AASHTO T 307. Since the testing procedure is still complex, the testing has not been widely implemented in practice. In this study, the applicability of a simplified procedure with a confining pressure of 2 psi and deviator stresses of 2, 4, 6, 8, 10, and 15 psi was investigated on the typical coarse-grained and fine-grained subgrade soils encountered in Indiana. The results obtained from the simplified procedure are comparable with those obtained from AASHTO T 307 which calls for 15 combinations of stresses. This shows the simplified procedure to be feasible and effective for design purpose. For soils exhibiting excessive permanent deformation, use of deformed length is desirable for more accurate calculation of Mr. Usually the soils compacted dry of optimum shows the largest Mr for coarse-grained soils due to capillary suction, but it not necessary true for fine-grained soils. A predictive model to estimate regression coefficients k1, k2, and k3 using 11 soil variables obtained from the soil property tests and the Standard Proctor tests was developed. The predicted regression coefficient compares well with measured ones.
     Daehyeon  Kim, Chosun University, South Korea, dkimgeo@gmail.com
     Nayyar Zia Siddiki, Indiana Department of Transportation

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05-2571 - Development of Hybrid Energy-Absorbing Reusable Terminal for Roadside Safety Applications
Session 215
The Hybrid Energy Absorbing Reusable Terminal (HEART) is a newly developed crash cushion or an end terminal to be used in highway safety applications that will mitigate injuries to occupants of errant vehicles. The HEART is composed of corrugated plates of High Molecular Weight/High-Density Polyethylene (HMW/HDPE), supported on steel diaphragms, which slide on a fixed rail. Kinetic energy from errant vehicles is converted to other energy forms through folding and deformation of the HMW/HDPE material. Many previous designs utilize plastic or permanent deformation of plastics or steels to accomplish this goal. However, HEART is a combination of plastic and steel which forms a largely self-restoring and largely reusable crash cushion. Consequently, HEART has a major lifecycle cost advantage over conventional crash cushion designs. HEART has been developed through extensive use of finite element analysis with LS-DYNA. This paper presents the simulation approach adopted for the development of the HEART, the construction details, and the description and results of crash tests performed so far to evaluate its performance. This paper also talks about some of the follow up work currently underway for approval from Federal Highway Administration (FHWA) as an acceptable crash cushion for use on the National Highway System.
     Nauman M. Sheikh P.E., Texas A&M Transportation Institute , nauman@tamu.edu

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05-2753 - Transition from Guardrail to Concrete Bridge Rail for Low-Speed Roadways
Session 215
In recent years, many state DOTs have had to modify their approach guardrail-to-concrete bridge rail transition systems to comply with the testing requirements of NCHRP Report 350. Generally, these transition systems are designed and tested for use on high-speed roadways. Because there are no national transition designs that have been developed and tested for lower speed conditions, the same transition standard is typically applied to all roadways regardless of speed. The new transition designs represent a significant increase in installation cost and complexity over some previous designs that were acceptable under NCHRP Report 230. Thus, it may be cost prohibitive to require use of the same design on all roadways. The purpose of this research was to develop a guardrail-to-concrete bridge rail transition that is suitable for use on lower speed roadways and that is less expensive and complex than current high-speed designs. A low-cost transition was successfully evaluated under NCHRP Report 350 Test Level 2 (TL-2) impact conditions. It is considered suitable for implementation on roadways with speed limits of 45 mph (70 km/h) or less. Use of this system provides significant savings in material and installation cost compared to high speed (i.e., TL-3) transitions.
     Roger P. Bligh, Texas A&M Transportation Institute , rbligh@tamu.edu

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05-2786 - Developing Guidelines for Median Barrier Installation: Benefit-Cost Analysis with Texas Data
Session 610
Guidelines for the installation of median barriers presented in the American Association of State Highway and Transportation Officials’ (AASHTO) Roadside Design Guide have remained essentially unchanged for over 30 years. In recent years, the need for improved guidance has prompted several States to reevaluate their guidelines and has also precipitated a nationwide research project administered by TRB. The objective of the study, on which this paper is based, was to develop improved guidelines for the use of median barriers on new and existing high-speed, multilane, divided highways in Texas. The purpose of this paper is to present some modeling and benefit/cost analysis results from that study, with focus on the results from a particular data set developed under a “cross-sectional with-without” study design. The highways of interest were those classified as Interstates, freeways, and expressways with 4 or more lanes and have posted speed limits of 55 mph (88 km/hr) or higher. The models employed to estimate median-related crash frequencies and severities, including the Poisson-gamma and ordered multinomial logit models, as well as modeling results from a full-Bayes estimation method are presented. Based on the modeling results, a preliminary benefit/cost analysis, in conjunction with some sensitivity analyses, for developing the guidelines for concrete and high-tension cable barriers is described. The paper ends with a discussion on the limitations of this study and potential future extensions.
     Shaw-Pin  Miaou, Transmidas Consulting Services, miaou-transmidas@suddenlink.net
     Roger P. Bligh, Texas A&M Transportation Institute
     Dominique  Lord, Texas A&M University

Design/Construction: Quality and Performance

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05-0025 - Reliability of Piezocone Penetration Test Methods for Estimating the Coefficient of Consolidation of Cohesive Soils
Session 260
This paper presents the evaluation of the current PCPT interpretation methods for their capability to reasonably estimate the vertical coefficient of consolidation (cv) of cohesive soils utilizing the piezocone dissipation tests. The PCPT methods included in this evaluation are: Teh and Houlsby (1), Levadoux and Baligh (2), Robertson and Campanella (3), Teh (4), Senneset et al. (5) (two methods), and Jones and Rust (6). To achieve this goal, six sites in Louisiana were selected for this study. In each site, in-situ PCPT tests were performed and soundings of cone tip resistance (qc), sleeve friction (fs), and pore pressures at different locations (u1 and u2) were recorded. Piezocone dissipation tests were also conducted at different penetration depths. High quality shelby tube samples were collected close to the PCPT tests and used to carry out a comprehensive laboratory-testing program. The vertical coefficient of consolidation (cv), predicted using the different interpretation methods, were compared with the reference values determined from the oedometer laboratory tests. The results of this research study showed that the Teh and Houlsby (1) and Teh (4) methods can estimate cv better than the other prediction methods.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens

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05-0037 - Application of Dynamic Cone Penetrometer in Pavement Construction Control
Session 260
This paper presents the results of a comprehensive testing program that was conducted to evaluate the potential use of the Dynamic Cone Pentrometer (DCP) device in the quality control/quality assurance (QC/QA) procedure during the construction of pavement layers and embankments. The laboratory tests were conducted on different materials prepared inside two test boxes 1.5m x 0.9m x 0.9m (5ft x 3ft x 3ft) located at Louisiana Transportation Research Center (LTRC). The field tests were conducted on different highway sections in Louisiana. In addition, nine test sections were constructed and tested at the Pavement Research facility (PRF) site of the LTRC. In all laboratory and field tests, DCP tests were conducted in companion with the Plate Load Test (PLT). In addition, Falling Weight Deflectometer (FWD) tests were conducted on the field sections. CBR laboratory tests were also performed on samples collected from the tested sections. Regression analysis was carried out on the collected data to correlate the DCP-PR with the three reference tests used in this study (PLT, FWD and CBR). Further field tests were conducted to verify the developed regression models. The results of these tests indicated that the developed models yielded good predictions of the measured FWD moduli and CBR values. This suggests that these models can be used to reliably evaluate the stiffness/strength of different pavement materials.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens
     Khalid A. Alshibli, University of Tennessee, Knoxville
     Ekram  Seyman, Louisiana State University

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05-0281 - Simplified Laboratory Assessment of Subgrade Performance Parameters for Mechanistic Design of Pavement Foundations
Session 260
With the increasing agenda for sustainability, the UK is attempting to move away from the empirical design of pavement foundations to develop a performance specification approach to facilitate analytical design. For analytical design the measurement of the subgrade performance parameters of stiffness and resistance to permanent deformation are required. These parameters ideally need to be assessed concurrently under loading and environmental conditions similar to those the materials will experience in the field. To date, measurement of these parameters is largely confined to research laboratories using cyclic triaxial testing with on sample strain measurement. This apparatus is considered too complicated for routine commercial use, hence this potentially limits the implementation of laboratory performance evaluation for pavement foundation design. A previous program of cyclic triaxial testing on clay subgrades indicated a series of useful correlations between strength and permanent deformation behavior (via a threshold stress), and material stiffness at this threshold. This paper reviews the previous work and utilizing these correlations presents data from tests on three different clay materials performed to develop simplified equipment and procedures for the routine measurement of the required design parameters. It is shown that simple monotonic tests can measure a subgrade stiffness for a simplified performance based design. It re-evaluates the previous data (in the light of the recent work) to show a boundary correlation that may allow a shear strength based parameter to control (in design) the onset of permanent deformation, and details how long-term subgrade water content changes can be accommodated.
     Matthew William Frost, Loughborough University, United Kingdom, m.w.frost@lboro.ac.uk
     Paul  Edwards, Scott Wilson Pavement Engineering Ltd., United Kingdom
     Paul Richard Fleming, Loughborough University, United Kingdom
     Stuart John Arnold, Ramboll Whitbybird

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05-0286 - Test for the Presence of Asphalt Antistripping Additive
Session 440
A small device available commercially has been developed that uses litmus paper and a spectrophotometer to analyze vapors from hot liquid asphalt binders and mixtures to determine the percentage of antistripping additive present. Approximately 60 five-point additive content-color index count regressions were performed on binders and mixtures to determine how well the device measured additive content. The regressions basically fit the quadratic format that is used by the manufacturer in the recommended calibration process. The regressions were best when the litmus color index count was calculated by subtracting the initial count of the blank strip from the final count after exposure for the mixtures. Changes to the instrument software and testing temperature were necessary as the investigation progressed to accommodate different grades of binders. After the planned testing was completed, some retesting of the binders was performed using modified equipment and procedures. The changes appeared to improve the consistency of the results; therefore, the author believes that additive testing in binders can be determined within +0.2 percent using the modified equipment and procedures. Test results with mixtures were less accurate than for binders; however, if the vapor trap is modified as described, the accuracy for mixtures should be improved substantially. Since the test can be performed quickly, it would be possible to perform multiple tests on a sample. This would increase the confidence of the test results.
     George William Maupin Jr., Virginia Center for Transportation Innovation and Research, Bill.Maupin@VDOT.Virginia.gov

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05-0346 - Use of Accelerated Loading Equipment for Determination of Long-Term Moisture Susceptibility of Hot-Mix Asphalt
Session 561
Stripping of HMA with moisture susceptible aggregates, under high temperature and aircraft loading has been a persistent problem in some areas of the Logan International Airport in Boston, Massachusetts. These problem mixes generally meet the retained tensile strength criteria, after freeze-thaw conditioning. This study was conducted to evaluate the use of accelerated loading equipment for identifying moisture susceptible mixes, and also to evaluate the effect of lime. Mixes with three different aggregates were prepared with PG 76-28 asphalt binder according to specifications. Specimens were conditioned by three different methods, 1) multiple cycles of freeze-thaw, 2) wet trafficking with the Model Mobile Load Simulator (MMLS3) and 3) cycles of stress with the Moisture Induced Stress Tester, (MIST). Thereafter the respective indirect tensile strengths were determined. The results showed that accelerated loading can provide useful information for evaluating resistance of HMA to moisture damage under traffic at high temperature. For mixes to have adequate resistance to moisture damage by volumetric expansion-contraction, acceptable tensile strength tests were needed after at least six freeze-thaw conditioning cycles. The evaluation of resistance to moisture damage under traffic at high temperature using moisture stress conditioning proved very promising. The methods should be investigated further. The use of hydrated lime, improved the resistance of HMA against moisture induced stress damage at high temperatures. On the basis of these conclusions, it is recommended that testing protocols, consisting of both freeze-thaw and accelerated loading/moisture induced stress testing at high temperature, be used for evaluating the most cost-effective anti-stripping agent (liquid or solid).
     Rajib B. Mallick, Worcester Polytechnic Institute, rajib@wpi.edu
     Robert  Pelland, Massachusetts Port Authority
     Frederick  Hugo P.E., University of Stellenbosch, South Africa

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05-0483 - Asphalt Mix Design Method for Permeability
Session 561
Because of the observed porosity of new Superpave mixes, the Virginia Transportation Research Council conducted several investigations of permeability. As a result of these investigations and other related national studies, a mix design permeability test method was developed. The method involves testing a group of specimens prepared in the lab at a range of air-void contents and developing a permeability-void regression plot. From the regression, the permeability of pavement can be estimated. The purpose of this project was to compare results between two labs using mixtures from 11 paving projects. There was general agreement between permeability-air voids regressions resulting from the testing for the two labs. In addition, testing of cores from six of the projects indicated that the lab method estimates pavement permeability rather well. Implementation of the test method by the Virginia Department of Transportation is discussed.
     George William Maupin Jr., Virginia Center for Transportation Innovation and Research, Bill.Maupin@VDOT.Virginia.gov

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05-0756 - Performance and Uniformity of Self-Compacting Concrete
Session 211
Self-compacting concrete (SCC) is an emerging concrete type where its cohesive yet flowable consistency help securing proper placement with good homogeneity. Such concrete can be achieved by adjusting mix proportions and incorporating adequate admixtures such as the viscosity modifying (VM) admixtures with no vibration. Yet, the impact of the mix proportions and the role played by the VM as opposed to superplasticizers (SP) admixtures is not fully understood. There also seems to be no unique means for assessment of such concrete and the correlation between various tests needs further work. This study aims at achieving better understanding of the influence of mix proportions on the properties of SCC. Twenty-six mixtures were prepared with various w/c, fine-to coarse aggregate ratio and admixture dosages. Fresh concrete tests including slump flow, L-box, U-box and hardened concrete tests including hardened density, compressive and flexural strength as well as the Rebound Hammer were performed. The uniformity of SCC properties along column specimens was examined. The results reveal that adjusting mix proportions has a major impact on fresh and hardened properties of SCC. The fresh concrete tests were found to correlate well with one another and the SCC strength was comparable to that of reference concrete made with mechanical vibration. Yet, SCC exhibited remarkable uniformity of properties within the components examined. This work suggests that future studies performed on SCC should involve large-sized specimens in which concrete properties are evaluated in various locations.
     Mohamed Nagib Abou-Zeid, American University in Cairo, Egypt, mnagiba@aucegypt.edu
     Mohamed Samir Roushdy, Al-Kharafi Contracting W.L.L., Kuwait

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05-0815 - Vibrating Hammer Compaction Test for Granular Soils and Dense-Graded Aggregates
Session 367
Excessive settlements can occur in granular soils where specified field compaction is based on Standard Proctor (ASTM D 698, AASHTO T 99) maximum dry unit weights. A laboratory test program evaluated alternative test methods for granular soil compaction control and showed that a Vibrating Hammer method (similar to British Standard BS 1377:1975, Test 14) has great promise for laboratory compaction of these soils. A One-Point Vibrating Hammer test on an oven-dried soil sample provides the maximum dry unit weight and water content range for effective field compaction of granular soils with up to 35 percent nonplastic fines or 15 percent plastic fines. The maximum dry unit weight obtained is comparable to that from the Vibrating Table test (ASTM D 4253), and is greater than that from the Standard Proctor test (ASTM D 698, AASHTO T 99). The effects of different test variables on obtainable dry unit weights are also presented in this paper, along with vibrating hammer compaction results for dense graded aggregates. While the One-Point test may not work for some dense graded aggregates, the possibility of a Two-Point Vibrating Hammer test is introduced.
     Adam Buser Prochaska EIT, Purdue University
     Vincent  Drnevich P.E., Ph.D., Purdue University, drnevich@purdue.edu
     Daehyeon  Kim, Chosun University, South Korea
     Kurt  Sommer, Indiana Department of Transportation

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05-0903 - Development of a Test Method to Measure the Quality of Milling Operations in Asphalt Pavements
Session 527
Cold milling operations have been utilized for over two decades in Indiana but little attention was given to the “quality” of the operations. Several alternatives for evaluating surface macrotexture were considered as a quality measure. ASTM E 965-96 was selected as the best existing procedure on which to base evaluation of milled surfaces. The Indiana DOT developed test method ITM 812-03T to make the ASTM procedures workable for milled surfaces. The initial quality of Hot Mix Asphalt (HMA) construction directly affects the return on investment with the long-term performance and the service life of a transportation facility. The initial quality of construction is directly dependent upon the quality of the aggregates and binders and the production and laydown operations. Construction factors affect the initial quality including surface preparation procedures that is the removal of distressed materials (cold milling) to develop a stable working platform on which Hot Mix Asphalt materials can be placed. The Indiana Hot Mix Asphalt contractors were experiencing numerous problems meeting the volumetric and density quality requirements on highway construction projects. A significant number of HMA mixtures were either being accepted with partial payment or replaced prior to being accepted. Investigation of the problem included observing the contractor’s Certified HMA Plant Production operations, mixture components (i.e., aggregates, binders, etc), mixture transportation, laydown and compaction, and also mixture sampling procedures. It was discovered that more problems existed when cold milling of the existing surface was included in the project. A solution to the noted issues resulted in the development of improved milling design and construction requirements, which includes quality measurements techniques for the milling operations. Key Words: Cold Milling, HMA, Hot Mix Asphalt, Quality, Macrotexture, Milling
     Victor Lee Gallivan, Gallivan Consulting, Inc., Lee@GallivanConsultingInc.com
     Joseph F. Gundersen, Indiana Department of Transportation

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05-1019 - Pore Pressure Measurement in Blast-Induced Liquefaction Experiments
Session 367
Blast-induced liquefaction experiments have been conducted at a number of test sites to evaluate lateral foundation resistance and soil improvement techniques. Tests can be constructed at full-scale without waiting for an earthquake to occur. In this extreme environment, pore pressure transducers must survive transient blast pressures of 41.4 MPa (6000 psi), yet have enough resolution to measure residual pore pressures of ± 0.69 kPa (0.1 psi). Three different transducer types were evaluated under these demanding conditions and the piezoresistive transducer was clearly found to be the most robust. These sensors were repeatedly subjected to extreme blast pressures and vibration, but still were able to provide accurate time histories of residual pore pressure despite occasional baseline shifts. Although these piezometers are more expensive than the other types, installation techniques were developed which allowed the piezometers to be recovered and reused in subsequent tests to reduce overall costs. These pore pressure sensors make it possible to define the extent of the liquefied zone during blast liquefaction experiment and to understand the soil behavior during cyclic loading of deep foundations.
     Kyle M. Rollins, Brigham Young University, rollinsk@byu.edu
     J. Dusty Lane, Lane Engineering, LLC
     Emily  Dibb, Brigham Young University
     Scott A. Ashford, Oregon State University
     A. Gray Mullins, University of South Florida

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05-1194 - Revising Specification Limits of Existing Quality Assurance Specification
Session 364
The results of a study to evaluate the existing SCDOT hot mix asphalt Quality Assurance specification are presented. When the existing specification was developed, assumed values were used for the standard deviations needed to establish the specification limits. Acceptance test results from 39 different projects were analyzed to determine standard deviation values that were being obtained for asphalt content, air voids, VMA, and density. For each project, standard deviation values were calculated for each lot, and these were then pooled to obtain a typical value for the project. The project values were then used to establish a typical process standard deviation value for each of the four acceptance characteristics. All of these standard deviation values proved to be smaller than those initially assumed, and resulted in the SCDOT narrowing the specification limits for each of the acceptance characteristics. The project standard deviation values justified that these changes were made to reflect the actual variability that was present, and not simply to tighten the specifications.
     James L. Burati Jr, Clemson University, jlbrt@clemson.edu

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05-1285 - Predicting Field Permeability from Testing Hot-Mix Asphalt Specimens Produced by Superpave Gyratory Compactor
Session 440
This study was conducted to develop laboratory and field permeability testing procedures for design and quality control of Superpave mixtures in Wisconsin. A total of 16 mixes used on 9 field projects, including fine-graded and coarse-graded mixes, were evaluated. The in-place field permeability was measured by using the NCAT device; field cores were taken for measuring permeability in the laboratory by using the ASTM D5084 method; and laboratory compaction was used to prepare and test samples from loose mixtures recovered from the field. Two compaction procedures, called Method A and Method B were used in this study to produce Superpave Gyratory Compacted (SGC) specimens that have similar thickness, air voids, and aggregate orientation of the field cores. The result indicates that Method B, which is based on using Ndesign gyrations for different sample sizes, can be used to produce samples that give permeability values similar to values measured for field cores. The results of this study also indicate a good relationship between field permeability (using the NCAT device) and lab permeability measured on field cores of fine-graded mixes with amount of passing No. 8 sieve (P8) higher than 45%. However, the relationship between field permeability and lab permeability measured on field cores of coarse-graded mix (P8 lower than 40%) is very poor. It is therefore concluded that the NCAT permeability device could possibly be used in the field for fine-graded mix (with P8 higher than 45%) to measure a permeability index that is related to the true permeability of field cores as measured by the ASTM D5084. However, to measure the field permeability of coarse-graded mix (P8 lower than 40%), an approach to prevent water leakage along the sealant due to rough pavement surface should be established. For coarse graded mixtures, there appears to be no current alternative better than taking field cores and testing them in the laboratory. For estimating permeability during mixture design, a simple method for preparing and testing permeability of SGC specimens and interpolating based on expected field density is introduced. The results represent a good estimate of the expected in-place field permeability.
     Kunnawee  Kanitpong, Asian Institute of Technology, Thailand, kanitpon@ait.ac.th
     Hussain U. Bahia, University of Wisconsin, Madison
     Jeffrey S. Russell, University of Wisconsin, Madison
     Robert  Schmitt, University of Wisconsin, Platteville

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05-1355 - SIMPLE METHODS TO ESTIMATE INHERENT AND STRESS-INDUCED ANISOTROPY OF AGGREGATE BASE
Session 723
This paper presents simple methods to estimate cross-anisotropic material properties of unbound aggregate assemblies on the basis of physical properties of the aggregates. A regression model was developed from a database consisting of aggregates from six sources. Three gradations were selected for each source and three compaction moisture contents were selected for each gradation (6 x 3 x 3 = 54 combinations). Levels of anisotropy calculated from the regression analysis were compared to levels of anisotropy predicted by a micromechanics model that accounts for directional forces as a result of the effect of particle orientation and the ratio of the normal contact stiffness to shear contact stiffness among particles. The effect of aggregate type, particle shape, and textural characteristics on the level of anisotropy of unbound aggregate bases is discussed. The results demonstrate that aggregate type, orientation, grading, and shape influence the level of cross-anisotropy, which has a substantial effect on the pavement responses that impact pavement design. The micromechanics analysis predicted a level of (inherent) anisotropy (ratio of horizontal to vertical modulus) ranging from 1.0 to 0.4; while experimental results demonstrate that the level of anisotropy can drop to as low as 0.1 due to the impact of repeated loading.
     Dallas N. Little, Texas A&M Transportation Institute , d-little@tamu.edu
     Eyad A. Masad, Texas A&M University
     Sung-Hee  Kim, Southern Polytechnic State University

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05-1356 - Evaluation of the Effectiveness of Catchment Ditches Along Ohio Roadways
Session 332
The effectiveness of catchment ditches along Ohio roadways was evaluated for 100 sites using the Oregon Rock Fall Hazard Rating System (RHRS), New York State Rock Slope Rating Procedure (RSRP), Colorado Rock Fall Simulation Program (CRSP), and Oregon Rock Fall Catchment Area Design Guide. Based on this evaluation, 48% of the ditches were ranked as adequate within an acceptable level of risk, 28 % were ranked as marginally adequate, and 24 % were ranked as inadequate. Although qualitative in nature, the ditch evaluation portion of the Oregon RHRS was found to be very useful. None of the ditches evaluated met the Ritchie ditch depth criteria. CRSP provided valuable information where the entire road cut was accessible for data collection. The Oregon Catchment Area Design Guide provided important remediation information. Remediation methods such as ditch widening, ditch regrading, ditch maintenance, and placement of catchment barriers were found to be effective at improving ditch performance.
     Abdul  Shakoor, Kent State University, ashakoor@kent.edu
     Jesse W. Davis, University of North Carolina, Chapel Hill

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05-1453 - Initial Ride Quality of Hot-Mix Asphalt Pavements
Session 527
Ride quality assessed with an inertial profiler on flexible pavement was used to provide initial information on the following key issues: repeatability associated with IRI values for a wide range of hot mix asphalt (HMA) material variables, timing of acceptance testing for initial ride quality, IRI changes with type of roadway, influence of stops and starts in the paving operation on ride quality, identification of “bump”, and effect of grinding on IRI. IRI was calculated for 25-foot intervals instead of the standard 0.1 mi (528 feet) for all testing in order to highlight local anomalies such as bumps due to paving stoppages. Results indicate that the standard deviation of three replicate passes with an inertial profiler is 5 in/mi (includes 46 HMA mixes). IRI measurements with time suggest that initial acceptance testing can be conducted within 7 days, thereby allowing more flexibility in scheduling by the agency. Limited traffic also slightly reduces the IRI values, which is to the contractor’s advantage. IRI values are defined for two-lane county roads, medium to high traffic facilities. Separate IRI ranges are suggested for each of these categories based on the type of HMA construction: new, repair and overlay, and mill and overlay. These ranges are set for best and good practices (continuous paving, no stoppages; consistent supply of trucks, very short stops). IRI values greater than 125 in/mi in any given 25-foot interval indicate a bump; bumps can be ground so that these areas have IRI values of less than 100 in/mi.
     Mary  Stroup-Gardiner, Gardiner Technical Services, LLC, marystroupgardiner@outlook.com
     Alan  Carter, Universite du Quebec, Canada
     Priyabrata (Thomas)  Das, Auburn University
     Brian  Bowman, Auburn University

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05-1517 - Formwork Pressure of Self-Consolidating Concrete in Tall Wall Field Applications
Session 211
The growing interest in the use of self-consolidating concrete (SCC) for a wide variety of structural applications has initiated a reexamination of its properties and current construction practices, and how they compare to conventional concrete. One property of interest is the formwork pressure of SCC and how it relates to conventional concrete. This work presents the results from three tall walls (28, 21.7 and 13 ft. tall) cast slowly with SCC, and a 10.6 ft. high column poured quickly using the same concrete as one of the walls. The research demonstrates that pressure of SCC against formwork drops very quickly just after the concrete material is placed. Measurements from the walls poured slowly show that the maximum recorded pressure falls far below the hydrostatic pressure and is closely related to the pouring rate. The experiments also reveal that formwork pressure exerted by SCC can be revitalized if vibrated, even if stiffening is already in progress
     Fernando  Tejeda-Dominguez, University of Illinois, Urbana-Champaign, tejedado@uiuc.edu
     David A. Lange, University of Illinois, Urbana-Champaign
     Matthew D. D'Ambrosia, University of Illinois, Urbana-Champaign

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05-1688 - Unbound Aggregate Rutting Models for Stress Rotations and Effects of Moving Wheel Loads
Session 723
This paper presents the latest research findings on stress rotations due to moving wheel loads and their effects on permanent deformation or rut accumulation in pavement granular layers. Realistic pavement stresses induced by moving wheel loads were examined in the unbound aggregate base and subbase layers and the important effects of rotation of principal stress axes were indicated for a proper characterization of the permanent deformation behavior. To account for the rutting performances of especially thick granular layers, a comprehensive set of repeated load triaxial tests were conducted in the laboratory. Triaxial test data were obtained and analyzed from testing aggregates under various realistic in-situ stress paths due to moving wheel loading. Permanent deformation characterization models were then developed based on the experimental test data to include the static and dynamic stress states and the slope of stress path loading. The models that also considered the stress path slope variations predicted best the stress path dependency of permanent deformation accumulation. In addition, multiple stress path tests conducted to simulate the extension-compression-extension type rotating stress states under a wheel pass gave much higher permanent strains than those of the compression only single path tests. The findings indicated actual traffic loading simulated by the multiple path tests could cause greater permanent deformations or rutting damage especially in the loose base/subbase when compared to deformations measured from a dynamic plate loading or a constant confining pressure type laboratory test.
     In Tai  Kim, University of Illinois, Urbana-Champaign
     Erol  Tutumluer, University of Illinois, Urbana-Champaign, tutumlue@illinois.edu

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05-1976 - Evaluation of Caltrans Test Method for Measuring Resistance of Compacted Bituminous Mixture to Moisture-Induced Damage
Session 440
This paper presents an evaluation of test results from two round robin tests conducted by the California Department of Transportation (Caltrans) in 2003 using the newly developed test for measuring resistance of compacted bituminous mixture to moisture induced damage (California Test 371) and the development of preliminary precision statements resulting from the round robin tests. The test is a modification of the AASHTO T-283-89 procedure using the recommendations of NCHRP Project 9-13. Twenty laboratories statewide participated in the tests. Thirteen of the laboratories participated twice. The material used in the round robin tests was dense-graded hot-mix asphalt. The loose mixtures were prepared by one laboratory and the same Rice value was provided to all laboratories. The evaluation includes examination of test data outliers, evaluation of means, precision, and test repeatability. The evaluation indicates the following: • The standard deviation of the tensile strength ratio (TSR) values from the two round robin tests falls within the ASTM D 4867 suggested between-laboratory precision criterion. However, the TSR range exceeds the ASTM D2s criterion. • More than half of the participating laboratories met the ASTM D 4867 within-laboratory precision criteria. • For evaluation of test repeatability, data from 11 participating laboratories indicate that nine laboratories achieved the same mean air void content and saturation for both round robin test series. Also, at least 4 of 11 laboratories achieved the same mean tensile strength for both round robin test series. Preliminary precision statements for inclusion in the newly developed test method were developed as below: • Within-Laboratory Precision o Single-operator standard deviation (1s) of tensile strength (unconditioned or conditioned samples) is 74 kPa o D2s range is 210 kPa • Between-Laboratory Precision o Multi-laboratory standard deviation of the TSR is 8% o D2s range is 23% The recommended precision statements developed as a part of this study may be refined as more test data are generated.
     Haiping  Zhou P.E., California Department of Transportation, haiping_zhou@dot.ca.gov

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05-2128 - Risks with Multiple Pay Factor Acceptance Plans
Session 364
It is rare that a state highway agency (SHA) uses only a single quality characteristic to determine the pay factor for a lot. This paper deals with two specific types of risk associated with the use of multiple quality characteristics: remove and replace provisions; and the effect on pay factor determination if the quality characteristics are correlated. First, computer simulation studies showed that typical acceptance plan provisions that call for lot removal and replacement at a given quality level, such as 60 PWL or 50 PWL, can place much greater risk on the contractor when they apply to multiple characteristics. An approach to correct his problem was developed. Next, a total of 1,742 sets of asphalt content (AC), air voids (AV), and VMA test results were analyzed for correlations. VMA was shown to be positively correlated with both AV and AC. Additional simulation studies showed that while this correlation does not affect the long-term average pay factor for a lot, it will increase the variability in the individual lot composite pay factors. The positive correlation also has the effect of increasing the weighting of AV and AC in the composite pay equation. The use of multiple quality characteristics for determining the pay factor for a lot introduces sources of risk that are not present when only one characteristic is used. Any SHA that uses multiple pay factors should consider performing the types of remove and replace and correlation analyses presented in this paper.
     James L. Burati Jr, Clemson University, jlbrt@clemson.edu

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05-2793 - Method for Automated Discontinuity Analysis of Rock Slopes with Three-Dimensional Laser Scanning
Session 632
This paper describes the interim results of a study to characterize discontinuous rock masses using 3D laser scanning data. One of the main advantages of this method is that now an unbiased, rapid and accurate discontinuity analysis can be done. With 3D laser scanning it is now also possible to measure rock faces whose access is restricted or rock slopes along highways or railway lines where working conditions are hazardous. It is also shown that the proposed method will also be cheaper than traditional manual survey and analysis methods. Laser scanning is a relative new surveying technique, which yields a so-called ‘point cloud’ set of data, where every single point represents a point in 3D space of the scanned rock surface. Since the density of the point cloud can be high (in the order of 5 mm to 1 cm), it allows for an accurate re-construction of the original rock surface in the form of a 3D interpolated and meshed surface, using different interpolation techniques. Through geometric analysis of this 3D mesh and plotting of the facet orientations in a polar plot, it is possible to observe clusters, which represent different rock mass discontinuity sets. With fuzzy k-means clustering algorithms individual discontinuity sets can be outlined automatically and the mean orientations of these identified sets can be computed. Assuming a Fisher’s distribution it is subsequently demonstrated that the facet outliers can be removed. Finally, it is shown that discontinuity set spacings can be calculated as well.
     Siefko  Slob, International Institute for Geo-Information Science and Earth Observation, Netherlands, slob@itc.nl
     Bart  Van Knapen, Delft University of Technology, Netherlands
     Robert  Hack, International Institute for Geo-Information Science and Earth Observation, Netherlands
     Alan Keith Turner, Colorado School of Mines
     John  Kemeny, University of Arizona

Environment and Energy

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05-0508 - Field Evaluation of Porous Friction Course for Noise Control
Session 480
In 2003, the Indiana Department of Transportation allowed a test section of Porous Friction Course (PFC) to be placed on I74 east of Indianapolis. This paper summarizes the design, construction and early performance of that surface compared to an adjacent SMA surface and a conventional Superpave HMA surface. All three mixes included steel slag aggregate and a PG76-22 binder. The PFC was designed at 18-22% air voids to provide a permeable surface. Noise measurements were made on all three surfaces using both the pass-by and close-proximity methods. The three surfaces were also evaluated in terms of surface texture using the Circular Texture Meter and friction using the Dynamic Friction Tester and towed friction trailer. Splash and spray were judged qualitatively. The early performance indicates that the PFC produced significantly lower noise levels, higher surface texture and friction, and reduced splash and spray compared to the other two surface types.
     Rebecca S. McDaniel, Purdue University, rsmcdani@purdue.edu
     William D. Thornton, Purdue University

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05-1766 - Comparison of Thin-Lift Hot-Mix Asphalt Surface Course Mixes in New Jersey
Session 480
The use of thin-lift HMA surface course mixes is starting gaining wide acceptance in the United States as a means of improving both ride quality and safety. These materials are generally classified as having an open-graded/gap-graded aggregate skeleton, nominal aggregate sizes of 12.5mm or less, higher than normal asphalt binder contents, and are placed in thickness’ less than one inch. The use of the thin-lift materials has found to improve wet weather driving conditions, reduce traffic noise associated with the tire/pavement interface, and improve the ride quality measurements. Thin-lift HMA surface course mixes typically found in New Jersey consist of open-graded friction courses (OGFC) and Novachip®, with a few roadway sections using micro-surfacing and stone-mastic asphalt (SMA). Each of these material types were evaluated to provide an assessment of their ride quality and safety. These thin-lift materials were compared to in-service dense-graded asphalt mixes (DGA) and Portland cement concrete (PCC). The PCC had surfaces that consisted on no treatment, transverse tined, and diamond grind. Noise measurements utilizing the Close Proximity method (CPX), wet skid resistance, and ride quality data consisting of RQI and IRI were used to establish “performance” comparisons between the different surface courses. The “performance” information, along with current costs associated with the materials and construction, can provide a means of establishing a cost-effectiveness for utilizing these surface treatments under specific situational conditions.
     Thomas A. Bennert, Rutgers University, bennert@rci.rutgers.edu
     Frank  Fee, Asphalt Pavement Technology, LLC
     Eileen C. Sheehy, New Jersey Department of Transportation
     Andris A. Jumikis PE, New Jersey Department of Transportation
     Robert W. Sauber, Consultant

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05-2566 - Road to Quiet Neighborhoods in Arizona
Session 480
The Arizona Quiet Pavement Pilot Program (QP3) is a $34 million project implemented to reduce highway related traffic noise. This pilot program represents the first time that pavement surface type has been allowed as a noise mitigation strategy on federally funded projects. The program will overlay most of the Phoenix metropolitan area PCCP with one inch of ARFC. As a condition of using pavement type as a mitigation strategy, ADOT developed a ten-year, $2 million research program to evaluate the efficacy of using ARFC. Historically, pavement surface type was not considered a permanent solution due to the change in acoustic properties with time. This research program will evaluate the change in pavement acoustic properties through three means, (1) conventional roadside testing (eg far field measurements), (2) the use of near field measurements, both Close Proximity (CPX) and Sound Intensity (SI), and (3) far field measurements taken within the surrounding neighborhoods. This paper provides an overview of the program development, presents the research conducted to support the decision to overlay the urban freeway, and the status of current research. Particular emphasis is placed on the development and use of near field measurement systems consisting of CPX and SI Preliminary results from the research to date indicate that the near field measurement systems are providing meaningful assessments of pavement acoustic performance and the SI and CPX methods compare favorably. The overlays placed reduce the near field measurement levels between 6 to 11 dBA. Average reductions of 5 dBA occurred in the neighborhoods.
     Larry A. Scofield, International Grooving and Grinding Association, lscofield@pavement.com
     Paul  Donavan, Illingworth & Rodkin, Inc.

Geology and Earth Materials

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05-0025 - Reliability of Piezocone Penetration Test Methods for Estimating the Coefficient of Consolidation of Cohesive Soils
Session 260
This paper presents the evaluation of the current PCPT interpretation methods for their capability to reasonably estimate the vertical coefficient of consolidation (cv) of cohesive soils utilizing the piezocone dissipation tests. The PCPT methods included in this evaluation are: Teh and Houlsby (1), Levadoux and Baligh (2), Robertson and Campanella (3), Teh (4), Senneset et al. (5) (two methods), and Jones and Rust (6). To achieve this goal, six sites in Louisiana were selected for this study. In each site, in-situ PCPT tests were performed and soundings of cone tip resistance (qc), sleeve friction (fs), and pore pressures at different locations (u1 and u2) were recorded. Piezocone dissipation tests were also conducted at different penetration depths. High quality shelby tube samples were collected close to the PCPT tests and used to carry out a comprehensive laboratory-testing program. The vertical coefficient of consolidation (cv), predicted using the different interpretation methods, were compared with the reference values determined from the oedometer laboratory tests. The results of this research study showed that the Teh and Houlsby (1) and Teh (4) methods can estimate cv better than the other prediction methods.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens

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05-0037 - Application of Dynamic Cone Penetrometer in Pavement Construction Control
Session 260
This paper presents the results of a comprehensive testing program that was conducted to evaluate the potential use of the Dynamic Cone Pentrometer (DCP) device in the quality control/quality assurance (QC/QA) procedure during the construction of pavement layers and embankments. The laboratory tests were conducted on different materials prepared inside two test boxes 1.5m x 0.9m x 0.9m (5ft x 3ft x 3ft) located at Louisiana Transportation Research Center (LTRC). The field tests were conducted on different highway sections in Louisiana. In addition, nine test sections were constructed and tested at the Pavement Research facility (PRF) site of the LTRC. In all laboratory and field tests, DCP tests were conducted in companion with the Plate Load Test (PLT). In addition, Falling Weight Deflectometer (FWD) tests were conducted on the field sections. CBR laboratory tests were also performed on samples collected from the tested sections. Regression analysis was carried out on the collected data to correlate the DCP-PR with the three reference tests used in this study (PLT, FWD and CBR). Further field tests were conducted to verify the developed regression models. The results of these tests indicated that the developed models yielded good predictions of the measured FWD moduli and CBR values. This suggests that these models can be used to reliably evaluate the stiffness/strength of different pavement materials.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens
     Khalid A. Alshibli, University of Tennessee, Knoxville
     Ekram  Seyman, Louisiana State University

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05-0281 - Simplified Laboratory Assessment of Subgrade Performance Parameters for Mechanistic Design of Pavement Foundations
Session 260
With the increasing agenda for sustainability, the UK is attempting to move away from the empirical design of pavement foundations to develop a performance specification approach to facilitate analytical design. For analytical design the measurement of the subgrade performance parameters of stiffness and resistance to permanent deformation are required. These parameters ideally need to be assessed concurrently under loading and environmental conditions similar to those the materials will experience in the field. To date, measurement of these parameters is largely confined to research laboratories using cyclic triaxial testing with on sample strain measurement. This apparatus is considered too complicated for routine commercial use, hence this potentially limits the implementation of laboratory performance evaluation for pavement foundation design. A previous program of cyclic triaxial testing on clay subgrades indicated a series of useful correlations between strength and permanent deformation behavior (via a threshold stress), and material stiffness at this threshold. This paper reviews the previous work and utilizing these correlations presents data from tests on three different clay materials performed to develop simplified equipment and procedures for the routine measurement of the required design parameters. It is shown that simple monotonic tests can measure a subgrade stiffness for a simplified performance based design. It re-evaluates the previous data (in the light of the recent work) to show a boundary correlation that may allow a shear strength based parameter to control (in design) the onset of permanent deformation, and details how long-term subgrade water content changes can be accommodated.
     Matthew William Frost, Loughborough University, United Kingdom, m.w.frost@lboro.ac.uk
     Paul  Edwards, Scott Wilson Pavement Engineering Ltd., United Kingdom
     Paul Richard Fleming, Loughborough University, United Kingdom
     Stuart John Arnold, Ramboll Whitbybird

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05-0312 - Evaluation of Geophysical Methods for Alaskan Material Sources
Session 365
A geophysical investigation was carried out at four material source sites in Alaska’s interior to evaluate the effectiveness of three geophysical methods for assisting in site characterization. The methods included: ground penetrating radar (GPR), seismic wave refraction, and electrical resistivity imaging (EI). Each of the three methods was used at four potential material sites for which borehole test data was available. One site was located on the Steese Highway and the others were along the Dalton Highway. The objective was to determine which method or methods can best be used to understand the geologic framework of a site under various conditions. Of particular interest was identifying the best geophysical approach, with regards to instrumentation, field procedures, analysis and presentation, for identifying and mapping materials that would be appropriate for transportation construction projects. Results showed that the success of the geophysical methods, in terms of useful results and ease of use, was very dependent on both surface and subsurface conditions of the particular site. The study found that the GPR was the most time- and cost-efficient method, however it provided the least subsurface penetration and quantitative information on the materials. Thus, at sites with thick sand/gravel layers, the GPR did not map the deeper boundaries as clearly as the seismic refraction or EI methods. However, seismic refraction, capable of significant depth of penetration, was ineffective in the presence of surface organic soils. Finally, although EI produced relatively detailed images showing lateral and vertical variations in resistivity, the interpretation of the information was, in some situations, ambiguous and could not always be correlated with the collected borehole data.
     Steve  Saboundjian Ph.D., P.E., Alaska Department of Transportation and Public Facilities, steve.saboundjian@alaska.gov
     Robert G. Dugan CPG, Golder Associates, Inc.
     John  Liu Ph.D., Golder Associates, Inc.

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05-0326 - Axle and Wheel Loads in Developing Countries and Consequences for Material Specifications
AFB30
Overloading of trucks is a serious problem in developing countries. It results in high axle and wheel loads which have a devastating effect on the pavement structure. It is common practice to express the damaging effect in terms of an equivalent number of standard axle loads. The question arises whether this is a useful approach in case of overloaded trucks. The reason for this doubt is because of the fact that due to poor maintenance of the trucks, improper loading etc, wheel loads might occur which are much higher than the axle load divided by the nr. of wheels. Furthermore contact pressures might be excessive because of high tire pressures that have to be used because of overloading. This paper describes the results of a rather extensive axle and wheel load survey that took place in Ghana in the early 1990’s. It will be shown that axle load measurements are not sufficient at all to determine the magnitude of the overloading problem. Wheel load and tire pressure measurements should always be part of surveys into the overloading of trucks. Furthermore it will be shown how material specifications should be increased in order road pavements to be able to sustain excessive loadings.
     André  Molenaar, Delft University of Technology, Netherlands, a.a.a.molenaar@tudelft.nl

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05-1318 - Validation of Enhanced Integrated Climatic Model Predictions with New Jersey Seasonal Monitoring Data
Session 642
Environment is one of the essential factors that influence pavement material behavior and consequently its performance. The variation of climatic patterns from region to region coupled with the variation of site specific conditions across North America make it difficult to develop standard models to account for seasonal variation in material properties for all regions. Therefore, the need to develop regional models becomes an essential requirement for most transportation departments. The Enhanced Integrated Climatic Model (EICM) was used to determine its suitability in predicting subsurface temperature and moisture conditions within New Jersey sites. The validation of the model was carried out using environmental data collected through pavement instrumentation as part of a large-scale research study being undertaken under the sponsorship of the New Jersey Department of Transportation (NJDOT). The validation was carried out using site-specific data as input to the model and compared the model output parameters against field-measured values. This paper reports the results of the validation for two of the instrumented sites. Results of the study do not indicate a high correlation between EICM-predicted temperature and moisture profiles for the various pavement layers as compared to measured values.
     Zubair  Ahmed, Stantec Consulting, zahmed@stantec.com
     Ivana  Marukic, Stantec Consulting
     Sameh  Zaghloul, International Transportation Asset Management Specialists (ITAMSs)
     Nicholas P. Vitillo, Center for Advanced Infrastructure and Transportation (CAIT)

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05-1355 - SIMPLE METHODS TO ESTIMATE INHERENT AND STRESS-INDUCED ANISOTROPY OF AGGREGATE BASE
Session 723
This paper presents simple methods to estimate cross-anisotropic material properties of unbound aggregate assemblies on the basis of physical properties of the aggregates. A regression model was developed from a database consisting of aggregates from six sources. Three gradations were selected for each source and three compaction moisture contents were selected for each gradation (6 x 3 x 3 = 54 combinations). Levels of anisotropy calculated from the regression analysis were compared to levels of anisotropy predicted by a micromechanics model that accounts for directional forces as a result of the effect of particle orientation and the ratio of the normal contact stiffness to shear contact stiffness among particles. The effect of aggregate type, particle shape, and textural characteristics on the level of anisotropy of unbound aggregate bases is discussed. The results demonstrate that aggregate type, orientation, grading, and shape influence the level of cross-anisotropy, which has a substantial effect on the pavement responses that impact pavement design. The micromechanics analysis predicted a level of (inherent) anisotropy (ratio of horizontal to vertical modulus) ranging from 1.0 to 0.4; while experimental results demonstrate that the level of anisotropy can drop to as low as 0.1 due to the impact of repeated loading.
     Dallas N. Little, Texas A&M Transportation Institute , d-little@tamu.edu
     Eyad A. Masad, Texas A&M University
     Sung-Hee  Kim, Southern Polytechnic State University

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05-1356 - Evaluation of the Effectiveness of Catchment Ditches Along Ohio Roadways
Session 332
The effectiveness of catchment ditches along Ohio roadways was evaluated for 100 sites using the Oregon Rock Fall Hazard Rating System (RHRS), New York State Rock Slope Rating Procedure (RSRP), Colorado Rock Fall Simulation Program (CRSP), and Oregon Rock Fall Catchment Area Design Guide. Based on this evaluation, 48% of the ditches were ranked as adequate within an acceptable level of risk, 28 % were ranked as marginally adequate, and 24 % were ranked as inadequate. Although qualitative in nature, the ditch evaluation portion of the Oregon RHRS was found to be very useful. None of the ditches evaluated met the Ritchie ditch depth criteria. CRSP provided valuable information where the entire road cut was accessible for data collection. The Oregon Catchment Area Design Guide provided important remediation information. Remediation methods such as ditch widening, ditch regrading, ditch maintenance, and placement of catchment barriers were found to be effective at improving ditch performance.
     Abdul  Shakoor, Kent State University, ashakoor@kent.edu
     Jesse W. Davis, University of North Carolina, Chapel Hill

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05-1367 - Development of Seasonal Adjustment Models for Flexible Pavements
Session 642
Pavement design and performance are highly influenced by environmental factors such as temperature and moisture. Since temperature and moisture conditions vary with time (daily, seasonal and longer cycles), adjustment models are required to account for these variations and to bring pavement response parameters measured at different periods to the same standard conditions. A study funded by the New Jersey Department of Transportation (NJDOT) and the Federal Highway Administration (FHWA) is underway to develop temperature and seasonal adjustment models that suit New Jersey conditions. These models will be used in the network- and project-level pavement evaluation, analysis and design. Twenty-four test sections were instrumented to continuously measure environmental and climatic parameters. Deflection testing is being performed on a monthly basis (and bi-monthly during the recovery periods) for the last two years. In addition, two 24-hour testing cycles, in which tests are repeated every 2 hours for a 24-hour period, were performed on selected sections. Comprehensive analyses are performed on the collected data; which include backcalculation to determine the in-situ structural capacity under different environmental conditions, correlation to correlate weather data and sub-surface parameters, and Analysis Of Variance (ANOVA) to study the significance of different environmental parameters on pavements. Regression analysis is then performed to develop models that can be used to predict the impact of environmental factors on pavement performance. Also, statistical and empirical temperature and seasonal correction models are developed. This paper presents the developed models and some of the findings of this study.
     Sameh  Zaghloul, International Transportation Asset Management Specialists (ITAMSs), sameh_zaghloul@hotmail.com
     Amr  Ayed, Stantec Consulting
     Halim Omar Abd El Halim, Carleton University, Canada
     Nicholas P. Vitillo, Center for Advanced Infrastructure and Transportation (CAIT)
     Nenad  Gucunski Ph.D., Rutgers University

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05-1609 - Resilient Modulus Testing on Indiana Subgrade Soils
Session 210
ABSTRACT Resilient modulus has been used for characterizing stress-strain behavior of subgrades in the design of pavements. Recently the Resilient modulus (Mr) testing procedure has been upgraded through AASHTO T 307. Since the testing procedure is still complex, the testing has not been widely implemented in practice. In this study, the applicability of a simplified procedure with a confining pressure of 2 psi and deviator stresses of 2, 4, 6, 8, 10, and 15 psi was investigated on the typical coarse-grained and fine-grained subgrade soils encountered in Indiana. The results obtained from the simplified procedure are comparable with those obtained from AASHTO T 307 which calls for 15 combinations of stresses. This shows the simplified procedure to be feasible and effective for design purpose. For soils exhibiting excessive permanent deformation, use of deformed length is desirable for more accurate calculation of Mr. Usually the soils compacted dry of optimum shows the largest Mr for coarse-grained soils due to capillary suction, but it not necessary true for fine-grained soils. A predictive model to estimate regression coefficients k1, k2, and k3 using 11 soil variables obtained from the soil property tests and the Standard Proctor tests was developed. The predicted regression coefficient compares well with measured ones.
     Daehyeon  Kim, Chosun University, South Korea, dkimgeo@gmail.com
     Nayyar Zia Siddiki, Indiana Department of Transportation

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05-1688 - Unbound Aggregate Rutting Models for Stress Rotations and Effects of Moving Wheel Loads
Session 723
This paper presents the latest research findings on stress rotations due to moving wheel loads and their effects on permanent deformation or rut accumulation in pavement granular layers. Realistic pavement stresses induced by moving wheel loads were examined in the unbound aggregate base and subbase layers and the important effects of rotation of principal stress axes were indicated for a proper characterization of the permanent deformation behavior. To account for the rutting performances of especially thick granular layers, a comprehensive set of repeated load triaxial tests were conducted in the laboratory. Triaxial test data were obtained and analyzed from testing aggregates under various realistic in-situ stress paths due to moving wheel loading. Permanent deformation characterization models were then developed based on the experimental test data to include the static and dynamic stress states and the slope of stress path loading. The models that also considered the stress path slope variations predicted best the stress path dependency of permanent deformation accumulation. In addition, multiple stress path tests conducted to simulate the extension-compression-extension type rotating stress states under a wheel pass gave much higher permanent strains than those of the compression only single path tests. The findings indicated actual traffic loading simulated by the multiple path tests could cause greater permanent deformations or rutting damage especially in the loose base/subbase when compared to deformations measured from a dynamic plate loading or a constant confining pressure type laboratory test.
     In Tai  Kim, University of Illinois, Urbana-Champaign
     Erol  Tutumluer, University of Illinois, Urbana-Champaign, tutumlue@illinois.edu

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05-1779 - Thaw Weakening Mitigation of Unpaved Roads in Vermont
Session 642
We evaluated the performance of several techniques thought to mitigate deterioration of unpaved roads during spring thaw. Each potential remedy was aimed at providing some combination of limiting the availability of moisture in the winter, improving drainage during spring and strengthening the upper portion of the road. With one exception, each technique implemented uses locally and/or commercially available materials and all were easy to construct, i.e., a town road crew could build it. Construction was followed by two seasons of monitoring. We compared the percentage of the road covered in ruts and strength estimates based on dynamic cone penetrometer values for treated and control sections. Methods that either 1) permanently improved the strength of the top 12 inches of the road or 2) decreased the water content of the upper 12 inches of the road resulted in significant performance improvement during spring thaw.
     Karen S. Henry PhD, United States Air Force Academy, Karen.Henry@usafa.edu
     James P. Olson, University of Vermont
     Stephen P. Farrington, Transcendev
     Christopher C Benda, Vermont Agency of Transportation
     John  Lens, GeoDesign Inc.

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05-1880 - Evolution of Pavement Winter Roughness
Session 603
The functional service level of roads is quantified in terms of roughness. This parameter considers every road surface defect causing passenger vehicle discomfort. Roughness is measured using a quality index, the IRI (International Roughness Index). Roughness gives an overall appreciation of road profile quality without, however, permitting a deeper analysis. In fact, the overall value of the IRI does not discriminate between the two main factors responsible for winter deterioration of roughness, the first being the subgrade differential heave and the second being heave cracks. Differential heave is obtained from the variability in frost susceptibility of subgrade. This phenomenon, which occurs deep in the subgrade, is detectable by isolating the long wave lengths produced at the road surface from the longitudinal profile. Heave cracks are a superficial phenomenon greatly influenced by the application of de-icing salts. By isolating the short wave lengths from the profile, it is possible to highlight the influence of this phenomenon on deterioration. The goal of this research is therefore to establish, using a filtering technique of road profile, the contribution of these two main factors to winter deterioration of roughness on five road sections in the Québec City area. This study will then allow the development of a tool to determine the dominant factor for deterioration and therefore the use of the best technique to rehabilitate roads.
     Nicolas  Fradette, No Organization
     Pascale  Pierre, Laval University, Canada, ppierre@gci.ulaval.ca
     Guy  Doré, Universite Laval, Canada
     Serge  Hébert, Laval University, Canada

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05-2690 - Can Spring Load Restrictions on Low-Volume Roads Be Shortened Without Increasing Road Damage?
Session 484
Major highways are designed to withstand heavy vehicles and high volumes of traffic year round. However, low volume roads in seasonal frost areas are highly susceptible to damage from trafficking by heavy vehicles during spring thaw. Conventional practice is to place partial or full spring load restrictions on low volume roads during spring thaw. This practice will reduce damage significantly. However, companies whose livelihood depends on trucking can suffer major economic losses as they await removal of load restrictions. Using reduced tire pressure constitutes a less conventional road usage technique that can also contribute toward reducing springtime damage. Reducing tire pressure generally appears to be less effective than reducing load. Nevertheless, it does appear that the load restriction window can be reduced in duration by implementing a reduction in tire pressure for a short duration starting toward the latter part of the standard spring load restriction. Using a mechanistic pavement design and evaluation model for seasonal frost areas that had been under development by the US Army Corps of Engineers, this paper discusses the development of a critical combination of load and tire pressure reduction that contributes toward optimizing the balance between minimizing springtime road damage and minimizing disruption to local economies caused by load restrictions.
     Maureen A. Kestler, USDA Forest Service, mkestler@fs.fed.us
     Richard L. Berg, FROST Associates
     John E. Haddock, Purdue University

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05-2793 - Method for Automated Discontinuity Analysis of Rock Slopes with Three-Dimensional Laser Scanning
Session 632
This paper describes the interim results of a study to characterize discontinuous rock masses using 3D laser scanning data. One of the main advantages of this method is that now an unbiased, rapid and accurate discontinuity analysis can be done. With 3D laser scanning it is now also possible to measure rock faces whose access is restricted or rock slopes along highways or railway lines where working conditions are hazardous. It is also shown that the proposed method will also be cheaper than traditional manual survey and analysis methods. Laser scanning is a relative new surveying technique, which yields a so-called ‘point cloud’ set of data, where every single point represents a point in 3D space of the scanned rock surface. Since the density of the point cloud can be high (in the order of 5 mm to 1 cm), it allows for an accurate re-construction of the original rock surface in the form of a 3D interpolated and meshed surface, using different interpolation techniques. Through geometric analysis of this 3D mesh and plotting of the facet orientations in a polar plot, it is possible to observe clusters, which represent different rock mass discontinuity sets. With fuzzy k-means clustering algorithms individual discontinuity sets can be outlined automatically and the mean orientations of these identified sets can be computed. Assuming a Fisher’s distribution it is subsequently demonstrated that the facet outliers can be removed. Finally, it is shown that discontinuity set spacings can be calculated as well.
     Siefko  Slob, International Institute for Geo-Information Science and Earth Observation, Netherlands, slob@itc.nl
     Bart  Van Knapen, Delft University of Technology, Netherlands
     Robert  Hack, International Institute for Geo-Information Science and Earth Observation, Netherlands
     Alan Keith Turner, Colorado School of Mines
     John  Kemeny, University of Arizona

Maintenance

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05-0326 - Axle and Wheel Loads in Developing Countries and Consequences for Material Specifications
AFB30
Overloading of trucks is a serious problem in developing countries. It results in high axle and wheel loads which have a devastating effect on the pavement structure. It is common practice to express the damaging effect in terms of an equivalent number of standard axle loads. The question arises whether this is a useful approach in case of overloaded trucks. The reason for this doubt is because of the fact that due to poor maintenance of the trucks, improper loading etc, wheel loads might occur which are much higher than the axle load divided by the nr. of wheels. Furthermore contact pressures might be excessive because of high tire pressures that have to be used because of overloading. This paper describes the results of a rather extensive axle and wheel load survey that took place in Ghana in the early 1990’s. It will be shown that axle load measurements are not sufficient at all to determine the magnitude of the overloading problem. Wheel load and tire pressure measurements should always be part of surveys into the overloading of trucks. Furthermore it will be shown how material specifications should be increased in order road pavements to be able to sustain excessive loadings.
     André  Molenaar, Delft University of Technology, Netherlands, a.a.a.molenaar@tudelft.nl

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05-0348 - Guidelines for Prime Coat Usage on Low-Volume Roads
Session 336
Prime coat has a purpose in the pavement construction process, yet many times prime is misused or eliminated during the project. While most of the time no harm appears to occur to the roadway and thus may be viewed as acceptable, technical guidance is warranted to assure appropriate usage. The objective of this study was to produce a prime coat guide publication developed for Central Federal Lands Highway Division (CFLHD) project development and field personnel to provide decision-making guidance on how to use, when to keep, and when to eliminate prime coat. The literature search, which focused on handbooks and technical reports, was conducted along with a review of agency construction specifications. A phone survey of current practice of state DOTs from the region was undertaken to provide information on current practice. Finally, a review of the potential harmful and positive environmental effects of the prime coat process, including the various bituminous products used, was undertaken. Based on the information collected, a guideline for project development and field personnel was developed. The guideline provides decision-making guidance on how to use, when to keep, and when to eliminate prime coats.
     Stephen  Cross, Oklahoma State University, steve.cross@okstate.edu
     Michael David Voth, Federal Highway Administration
     Pramed P Shrestha, Oklahoma State University

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05-1511 - Maintenance and Rehabilitation of Low-Volume Pavements in Washington State
Session 336
The vast majority of pavements worldwide can be classified as low-volume. Pavement maintenance and rehabilitation practices on these roads are vital to their continued serviceability. Proven successful and efficient strategies are in demand considering that low-volume roads are typically managed by agencies with extremely limited resources. The Washington State Pavement Management System (WSPMS), which has been functioning continuously for over 30 years, provides a rich data set from which to investigate maintenance and rehabilitation practices on low-volume pavements in Washington State. This investigation seeks to determine common maintenance, rehabilitation, design and material characteristics in WSDOT managed low-volume pavements and measures of their success. Records indicate that over two-thirds of WSDOT’s low-volume pavements are bituminous surface treatments, while almost one-third are hot mix asphalt surfaced pavements. These pavements, many of which have lasted in excess of 35 years, are in relatively good condition and are typically subject only to periodic rehabilitation treatments every 8 to 20 years and responsive pothole patching. This evidence suggests that the concept of a long-lasting low-volume pavement is viable and, in fact, already exists. More study is required to determine the physical, construction and preservation principles behind this phenomenon.
     Stephen T. Muench, University of Washington, stmuench@uw.edu
     George C. White, University of Washington
     Joe P. Mahoney, University of Washington
     Nadarajah  Sivaneswaran, Federal Highway Administration
     Linda M. Pierce, Applied Pavement Technology, Inc.

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05-1951 - Development of Surfacing Criteria for Low-Volume Roads in South Dakota
Session 336
On a daily basis, local road agencies in South Dakota face the challenge of how to cost-effectively maintain low-volume roads. Specifically, agencies are faced with the decision of determining when it is most economical to maintain, upgrade, or downgrade a road’s existing surface. In order to assist decision makers with these types of maintenance and rehabilitation decisions, the South Dakota Department of Transportation (SDDOT) initiated a research study in 2002 to investigate surfacing criteria for low-volume roads (LVR). The overall objective of this research study is to create a process that allows the user to compare the costs associated with different types of roads to provide assistance in deciding which surface type (hot-mix asphalt [HMA], blotter, gravel, or stabilized gravel) is most economical under a specific set of circumstances. In addition to incorporating economic factors into the analysis, the process allows the user to consider other non-economic factors that are more subjective and difficult to quantify. The process used during this study is flexible enough to allow users to consider any combination of agency costs incurred by the agency for maintaining its roads, non-agency (user) cost factors such as vehicle operating costs or crash potential, and non-economic factors such as politics and housing densities. The methodology was created using agency cost and user cost models that were developed based upon specific road section information supplied by various local agencies in South Dakota, average daily traffic (ADT) and crash occurrence information supplied by the SDDOT, information obtained through a literature search, and input from members of the project’s Technical Panel.
     Angela S. Wolters, Applied Pavement Technology, Inc.
     Kathryn A. Zimmerman P.E., Applied Pavement Technology, Inc., kzimmerman@appliedpavement.com
     David L. Huft, South Dakota Department of Transportation
     Paul A. Oien, South Dakota Department of Transportation

Operations

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05-0326 - Axle and Wheel Loads in Developing Countries and Consequences for Material Specifications
AFB30
Overloading of trucks is a serious problem in developing countries. It results in high axle and wheel loads which have a devastating effect on the pavement structure. It is common practice to express the damaging effect in terms of an equivalent number of standard axle loads. The question arises whether this is a useful approach in case of overloaded trucks. The reason for this doubt is because of the fact that due to poor maintenance of the trucks, improper loading etc, wheel loads might occur which are much higher than the axle load divided by the nr. of wheels. Furthermore contact pressures might be excessive because of high tire pressures that have to be used because of overloading. This paper describes the results of a rather extensive axle and wheel load survey that took place in Ghana in the early 1990’s. It will be shown that axle load measurements are not sufficient at all to determine the magnitude of the overloading problem. Wheel load and tire pressure measurements should always be part of surveys into the overloading of trucks. Furthermore it will be shown how material specifications should be increased in order road pavements to be able to sustain excessive loadings.
     André  Molenaar, Delft University of Technology, Netherlands, a.a.a.molenaar@tudelft.nl

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05-2793 - Method for Automated Discontinuity Analysis of Rock Slopes with Three-Dimensional Laser Scanning
Session 632
This paper describes the interim results of a study to characterize discontinuous rock masses using 3D laser scanning data. One of the main advantages of this method is that now an unbiased, rapid and accurate discontinuity analysis can be done. With 3D laser scanning it is now also possible to measure rock faces whose access is restricted or rock slopes along highways or railway lines where working conditions are hazardous. It is also shown that the proposed method will also be cheaper than traditional manual survey and analysis methods. Laser scanning is a relative new surveying technique, which yields a so-called ‘point cloud’ set of data, where every single point represents a point in 3D space of the scanned rock surface. Since the density of the point cloud can be high (in the order of 5 mm to 1 cm), it allows for an accurate re-construction of the original rock surface in the form of a 3D interpolated and meshed surface, using different interpolation techniques. Through geometric analysis of this 3D mesh and plotting of the facet orientations in a polar plot, it is possible to observe clusters, which represent different rock mass discontinuity sets. With fuzzy k-means clustering algorithms individual discontinuity sets can be outlined automatically and the mean orientations of these identified sets can be computed. Assuming a Fisher’s distribution it is subsequently demonstrated that the facet outliers can be removed. Finally, it is shown that discontinuity set spacings can be calculated as well.
     Siefko  Slob, International Institute for Geo-Information Science and Earth Observation, Netherlands, slob@itc.nl
     Bart  Van Knapen, Delft University of Technology, Netherlands
     Robert  Hack, International Institute for Geo-Information Science and Earth Observation, Netherlands
     Alan Keith Turner, Colorado School of Mines
     John  Kemeny, University of Arizona

Pavement Management

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05-0032 - Statistical Analysis of Automated Versus Manual Pavement Condition Surveys
Session 369
The Alabama Department of Transportation (ALDOT) has used a vendor to perform automated pavement condition surveys for the Alabama pavement network since 1997. In 2002, ALDOT established a quality assurance (QA) program to check the accuracy of the automated pavement condition data. The QA program resulted in the discovery of some significant discrepancies between manual and automatically collected data. ALDOT uses a composite pavement condition index called Pavement Condition Rating (PCR) in their pavement management system. The equation for PCR was developed in 1985 for use with manual pavement condition surveys; however, ALDOT continues to use it with data from automated condition surveys. Since the PCR equation was developed for manual surveys, the discrepancies between the manual and automated data led ALDOT to question the continuity between their manual and automated pavement condition survey programs. A regression analysis was completed in an effort to look for any systematic error or general trends in the error between automated and manual data. Also, Monte Carlo simulation was used to determine which distress parameters most influence the PCR and whether they require more accuracy. The regression analysis showed the following general trends: automated data over report outside wheelpath rut depth, underreport alligator severity level 1 cracking, and over report alligator severity level 3 cracking. Through Monte Carlo simulation, it was determined that all severity levels of transverse cracking, block cracking, and alligator cracking data require greater accuracy.
     Jason M. McQueen, Consulting Engineer
     David H. Timm P.E., Auburn University, timmdav@auburn.edu

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05-0326 - Axle and Wheel Loads in Developing Countries and Consequences for Material Specifications
AFB30
Overloading of trucks is a serious problem in developing countries. It results in high axle and wheel loads which have a devastating effect on the pavement structure. It is common practice to express the damaging effect in terms of an equivalent number of standard axle loads. The question arises whether this is a useful approach in case of overloaded trucks. The reason for this doubt is because of the fact that due to poor maintenance of the trucks, improper loading etc, wheel loads might occur which are much higher than the axle load divided by the nr. of wheels. Furthermore contact pressures might be excessive because of high tire pressures that have to be used because of overloading. This paper describes the results of a rather extensive axle and wheel load survey that took place in Ghana in the early 1990’s. It will be shown that axle load measurements are not sufficient at all to determine the magnitude of the overloading problem. Wheel load and tire pressure measurements should always be part of surveys into the overloading of trucks. Furthermore it will be shown how material specifications should be increased in order road pavements to be able to sustain excessive loadings.
     André  Molenaar, Delft University of Technology, Netherlands, a.a.a.molenaar@tudelft.nl

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05-0348 - Guidelines for Prime Coat Usage on Low-Volume Roads
Session 336
Prime coat has a purpose in the pavement construction process, yet many times prime is misused or eliminated during the project. While most of the time no harm appears to occur to the roadway and thus may be viewed as acceptable, technical guidance is warranted to assure appropriate usage. The objective of this study was to produce a prime coat guide publication developed for Central Federal Lands Highway Division (CFLHD) project development and field personnel to provide decision-making guidance on how to use, when to keep, and when to eliminate prime coat. The literature search, which focused on handbooks and technical reports, was conducted along with a review of agency construction specifications. A phone survey of current practice of state DOTs from the region was undertaken to provide information on current practice. Finally, a review of the potential harmful and positive environmental effects of the prime coat process, including the various bituminous products used, was undertaken. Based on the information collected, a guideline for project development and field personnel was developed. The guideline provides decision-making guidance on how to use, when to keep, and when to eliminate prime coats.
     Stephen  Cross, Oklahoma State University, steve.cross@okstate.edu
     Michael David Voth, Federal Highway Administration
     Pramed P Shrestha, Oklahoma State University

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05-0805 - Use of Microcracking to Reduce Shrinkage Cracking in Cement-Treated Bases
Session 411
Shrinkage cracking occurs in cement-treated bases due to desiccation and cement hydration; eventually these cracks start to reflect through the pavement surfacing. While initially considered cosmetic in nature, these cracks open the pavement to water infiltration and increase the likelihood of accelerated pavement distress. Although numerous options exist for minimizing the amount of reflective cracks that appear, this paper focuses on the performance of controlled test sections utilizing a promising approach termed “microcracking.” The microcracking concept can be defined as the application of several vibratory roller passes to the cement treated base at a short curing stage, typically after one to three days, to create a fine network of thin cracks. In addition to the microcracked test sites, the contractor constructed moist cured, dry cured, and asphalt curing membrane sites for comparison. Researchers used falling weight deflectometer (FWD) tests to control the microcracking process, periodic crack surveys to monitor crack performance, and FWD tests through time to track base moduli. Microcracking proved quite effective at reducing shrinkage cracking problems in the base; applying the procedure with three passes of the roller after two to three days curing resulted in the best performance. Additionally, researchers observed that without microcracking, excessively high cement contents result in problematic cracking in the base even if cured according to good construction practice. Microcracking did not result in pavement damage or diminished in-service modulus; thus, microcracking should be considered a viable and inexpensive option to incorporate shrinkage crack control into construction of cement-treated bases.
     Stephen  Sebesta, Texas A&M Transportation Institute , s-sebesta@tamu.edu

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05-0925 - Assessment of Aging at FHWA's Pavement Testing Facility
Session 708
Field cores were taken in 1995 and 2002 from 8 asphalt pavements constructed in 1993 at the Federal Highway Administration’s pavement testing facility to evaluate the in-situ pavement aging. Dynamic mechanical properties of these cores were evaluated using the Superpave Shear Tester. The moduli of aged pavements were also predicted from binder, aggregate, and mixture properties using available prediction models, and the aging severity levels of all pavements were compared between the lab-measured and model-predicted. Eight pavements with two polymer-modified and six unmodified binders were evaluated in this study. Polymer-modified asphalt pavements showed comparatively lower aging than unmodified asphalt pavements. For unmodified asphalt pavements, stiffer asphalts tended to have higher aging indices. The binder aging index was found to be inversely proportional to the loading frequency, and differences between the aging indices for different binders were higher at lower frequency. Comparison between lab-measured and model-predicted binder aging indices showed a good agreement in ranking for all binders. Low stiffness binders, e.g., AC-5, showed higher aging indices than high stiffness binders, e.g., Styrelf. Pavement depth significantly impacted binder aging. The aging index near the surface (6.35 mm) was found to be about 4 to 5 times the aging index at a depth of 139.7 mm in pavement. Comparison between lab-measured and model-predicted mixture aging indices showed large variations, from over-predicted to well under-predicted, depending on the binder type and nominal maximum aggregate size.
     Ghazi G. Al-Khateeb, Jordan University of Science and Technology, ggalkhateeb@just.edu.jo
     Xicheng  Qi, Federal Highway Administration
     Aroon  Shenoy, Federal Highway Administration
     Kevin D. Stuart, Federal Highway Administration
     Terry M. Mitchell, Federal Highway Administration

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05-0935 - Quantifying Lateral Displacement of Trucks for Use in Flexible Pavement Design
Session 648
Current flexible pavement design procedures in the United States are based upon the AASHO Road Test and subsequent updates and have not considered lateral displacement of vehicles across a pavement lane as a design input until the recent release of the 2002 AASHTO Pavement Design Guide for New and Rehabilitated Pavements. The lateral displacement of vehicles (wheel wander) has been identified by researchers around the world. As design methods are improved to better represent traffic loading in the field, wheel wander becomes increasingly important. This research has developed a model for wheel wander based on field data from highways. Data were collected using a developed reference system, which was painted on the pavement. Traffic was then video taped and the positions within the lane were recorded for 7761 tire contact points on 31 roadway sections. It was found that wheel wander on interstate highways can be modeled by a normal distribution with a mean of 110.6 inches (280.9 cm) with respect to the center pavement lane marking and a standard deviation of 12.1 inches (30.7 cm). The center pavement lane marking was determined to be the most consistent frame of reference for measuring wheel wander. The AASHTO 2002 Pavement Design Guide for New and Rehabilitated Pavements, which uses mechanistic-empirical pavement design procedures, will be able to take into account this lateral displacement of traffic loading and will require numerical values for mean wheel position and standard deviation. This research provides mean and standard deviation values that can be used in this design procedure.
     Jeffrey J. Stempihar, Michigan Technological University
     Ronald Christopher Williams, Iowa State University, rwilliam@iastate.edu
     Thomas D. Drummer, Michigan Technological University

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05-1109 - Influence of Truck Volume Distribution on Flexible Pavement Performance
Session 609
Accurate knowledge of truck volume and loading is essential to pavement design and performance. Underestimation of design traffic results in premature pavement failure and excessive rehabilitation costs, while overestimation results in an overly conservative pavement design that is not cost effective for owner agencies. The recently developed National Cooperative Highway Research Program (NCHRP) 1-37A Design Guide (i.e., new design guide) specifically addresses truck volume distribution via the traffic input software module. Within the module, the user has an opportunity to specify average annual daily truck traffic (AADTT), monthly and hourly truck volume distribution, vehicle class distribution, and anticipated traffic growth over the design life. Influence of these traffic factors on hot flexible pavement performance was determined with the new NCHRP design guide software for two highways in Mississippi. Results indicate AADTT, vehicle classification and traffic growth distribution most influence rutting, fatigue cracking, and longitudinal cracking distresses. Monthly and hourly truck distributions were not found to substantially influence performance.
     Shane  Buchanan, APAC, Inc., shane.buchanan@oldcastlematerials.com

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05-1197 - Prediction of Pavement Crack Initiation from In-Service Pavements: A Duration Model Approach
Session 369
It is widely accepted that the success of pavement management systems largely depends on the quality of the deterioration models embedded in their structure. As such, large amounts of research have concentrated on developing a large array of approaches to model and predict pavement distress and deterioration. The objective of this paper is to develop surface distress prediction models for pavement failure times (the initiation of cracking on the surface of flexible and semi-rigid pavements) on the basis of a large (more that 1,000 observations) and recent (1998) data set collected from in-service pavements in 15 European countries using the principles of stochastic duration (hazard) models. The results indicate that, as expected, construction, traffic and climatic factors affect pavement distress and that the lognormal functional form, in contrast with the findings of previous studies, best describes the distress initiation process.
     Andreas  Loizos, National Technical University of Athens, Greece
     Matthew G. Karlaftis, National Technical University of Athens, Greece, mgk@central.ntua.gr

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05-1262 - Accelerated Pavement Rehabilitation and Reconstruction with Long-Life Asphalt Concrete on High-Traffic Urban Highways
Session 679
Rehabilitation of urban highways is a critical issue confronting the California Department of Transportation (Caltrans) since it has a significant inventory of over-aged, heavily-trafficked urban highways showing extensive signs of distress. This paper presents the innovative pavement rehabilitation technologies and techniques that the agency applied in the first asphalt concrete (AC) project for its Long-life Pavement Rehabilitation Strategies (LLPRS) program. A 4.4 km stretch of deteriorated concrete pavement on Interstate-710 (I-710) in Long Beach was rehabilitated successfully with 230 mm of AC overlay or 325 mm of full-depth AC replacement during eight 55-hour weekend closures. The pilot project proved that the accelerated (fast-track) rehabilitation with 55-hour weekend closures is a viable option that can drastically shorten overall construction time and lessen negative effects of construction in an urban area. The project also proved that AC pavement designed to provide a 30+ year design life can be constructed in a series of weekend closures even on the most heavily loaded truck route in the state. The construction monitoring study indicated that contractor productivities were noticeably improved (learning effect) as weekend closures were repeated. The pay factor clause in the contract effectively encouraged quality awareness on the part of the contractor. The traffic measurements study showed that traffic operated at free-flow speeds throughout the surrounding highways and arterial roads during the construction weekends. It is expected that the construction and traffic management techniques adopted in this project will be utilized in future LLPRS projects on California urban highways with high traffic volume.
     Eul-Bum  Lee, University of California, Berkeley, dreblee@postech.ac.kr
     Hojung  Lee, University of California, Berkeley
     Massod  Akbarian, California Department of Transportation

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05-1318 - Validation of Enhanced Integrated Climatic Model Predictions with New Jersey Seasonal Monitoring Data
Session 642
Environment is one of the essential factors that influence pavement material behavior and consequently its performance. The variation of climatic patterns from region to region coupled with the variation of site specific conditions across North America make it difficult to develop standard models to account for seasonal variation in material properties for all regions. Therefore, the need to develop regional models becomes an essential requirement for most transportation departments. The Enhanced Integrated Climatic Model (EICM) was used to determine its suitability in predicting subsurface temperature and moisture conditions within New Jersey sites. The validation of the model was carried out using environmental data collected through pavement instrumentation as part of a large-scale research study being undertaken under the sponsorship of the New Jersey Department of Transportation (NJDOT). The validation was carried out using site-specific data as input to the model and compared the model output parameters against field-measured values. This paper reports the results of the validation for two of the instrumented sites. Results of the study do not indicate a high correlation between EICM-predicted temperature and moisture profiles for the various pavement layers as compared to measured values.
     Zubair  Ahmed, Stantec Consulting, zahmed@stantec.com
     Ivana  Marukic, Stantec Consulting
     Sameh  Zaghloul, International Transportation Asset Management Specialists (ITAMSs)
     Nicholas P. Vitillo, Center for Advanced Infrastructure and Transportation (CAIT)

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05-1353 - Strategic Plan of the Texas Department of Transportation for Implementing NCHRP 1-37A Pavement Design Guide
Session 572
The NCHRP 2002 Guide has recently been released for research purposes. It was used in this study to develop a strategic plan for its implementation for the Texas Department of Transportation (TxDOT) operations. The paper focuses on the design of new flexible pavements. The new guide includes all possible variables that may affect the pavement performance. A general sensitivity study of these variables was conducted using an early version of the software. A few focused studies are presented, including: (1) preliminary local calibration of the guide using 11 SHRP GPS sections in Texas; (2) traffic composition effect compared to that of the traditional 80 kN ESALs and of the design load, and (3) effect of the choice of the whether station and of changing the water table depth on performance of the pavement. The results indicate that: (1) the use of the 80 kN ESALs leads to under-designing the structure; (2) the design load concept can be used in screening runs to determine a preliminary design and (3) in the case analyzed, changing the depth of the water table resulted in changing the moduli of the unbound material, but did not affect the performance. Finally, a strategy for implementation was recommended to TxDOT, including (1) training; (2) laboratory testing and equipment acquisition; (3) field forensic studies for calibration; (4) calibration and validation of the guide and (5) additional studies.
     Thomas John Freeman, Texas A&M Transportation Institute , t-freeman@tamu.edu
     Jacob  Uzan, Technion - Israel Institute of Technology
     Gregory Scott Cleveland, HDR Engineering, Inc.

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05-1355 - SIMPLE METHODS TO ESTIMATE INHERENT AND STRESS-INDUCED ANISOTROPY OF AGGREGATE BASE
Session 723
This paper presents simple methods to estimate cross-anisotropic material properties of unbound aggregate assemblies on the basis of physical properties of the aggregates. A regression model was developed from a database consisting of aggregates from six sources. Three gradations were selected for each source and three compaction moisture contents were selected for each gradation (6 x 3 x 3 = 54 combinations). Levels of anisotropy calculated from the regression analysis were compared to levels of anisotropy predicted by a micromechanics model that accounts for directional forces as a result of the effect of particle orientation and the ratio of the normal contact stiffness to shear contact stiffness among particles. The effect of aggregate type, particle shape, and textural characteristics on the level of anisotropy of unbound aggregate bases is discussed. The results demonstrate that aggregate type, orientation, grading, and shape influence the level of cross-anisotropy, which has a substantial effect on the pavement responses that impact pavement design. The micromechanics analysis predicted a level of (inherent) anisotropy (ratio of horizontal to vertical modulus) ranging from 1.0 to 0.4; while experimental results demonstrate that the level of anisotropy can drop to as low as 0.1 due to the impact of repeated loading.
     Dallas N. Little, Texas A&M Transportation Institute , d-little@tamu.edu
     Eyad A. Masad, Texas A&M University
     Sung-Hee  Kim, Southern Polytechnic State University

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05-1367 - Development of Seasonal Adjustment Models for Flexible Pavements
Session 642
Pavement design and performance are highly influenced by environmental factors such as temperature and moisture. Since temperature and moisture conditions vary with time (daily, seasonal and longer cycles), adjustment models are required to account for these variations and to bring pavement response parameters measured at different periods to the same standard conditions. A study funded by the New Jersey Department of Transportation (NJDOT) and the Federal Highway Administration (FHWA) is underway to develop temperature and seasonal adjustment models that suit New Jersey conditions. These models will be used in the network- and project-level pavement evaluation, analysis and design. Twenty-four test sections were instrumented to continuously measure environmental and climatic parameters. Deflection testing is being performed on a monthly basis (and bi-monthly during the recovery periods) for the last two years. In addition, two 24-hour testing cycles, in which tests are repeated every 2 hours for a 24-hour period, were performed on selected sections. Comprehensive analyses are performed on the collected data; which include backcalculation to determine the in-situ structural capacity under different environmental conditions, correlation to correlate weather data and sub-surface parameters, and Analysis Of Variance (ANOVA) to study the significance of different environmental parameters on pavements. Regression analysis is then performed to develop models that can be used to predict the impact of environmental factors on pavement performance. Also, statistical and empirical temperature and seasonal correction models are developed. This paper presents the developed models and some of the findings of this study.
     Sameh  Zaghloul, International Transportation Asset Management Specialists (ITAMSs), sameh_zaghloul@hotmail.com
     Amr  Ayed, Stantec Consulting
     Halim Omar Abd El Halim, Carleton University, Canada
     Nicholas P. Vitillo, Center for Advanced Infrastructure and Transportation (CAIT)
     Nenad  Gucunski Ph.D., Rutgers University

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05-1395 - Development of Methodology to Include Structural Contribution of Alternative Working Platforms in Pavement Structure
Session 338
This study was conducted to develop a methodology to incorporate the structural contribution of working platforms, including those constructed with industrial by-products, into the design of flexible pavements. Structural contribution of the working platform was quantified using the 1993 AASHTO flexible pavement design guide in terms of a structural number or an effective roadbed modulus. Resilient modulus obtained from large-scale model experiments conducted on several working platform materials (i.e., breaker run, grade 2 gravel, foundry slag, foundry sand, and bottom ash) were used in the analysis. Design charts are presented that show the structural number or the roadbed modulus as a function of type of material and thickness of the working platform.
     Burak Fevzi Tanyu, George Mason University, btanyu@gmu.edu

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05-1407 - Implementation Initiatives of the Mechanistic-Empirical Pavement Design Guides in Indiana
Session 572
The release of the Mechanistic-Empirical Design Guide for New and Rehabilitated Pavement Structures or M-E Design Guide generates a new paradigm in designing and analyzing pavement structures. No longer will an agency design pavement sections with minimal input using a design procedure where thickness is based on empirical relationships with no requirements of meeting performance criteria. In meeting the increased traffic demand, a new pavement design procedure is needed to assure that selected performance criteria are met during the design life. A desire to have a more accurate pavement design however, is countered with considerable amount of information needed often leading to complexities in the design process. In implementing the M-E Design Guides, in-depth knowledge of pavements and implementation planning have to be attained for optimal utilization of the design input requirements. More design inputs do not always guarantee a rational design; rather, thorough knowledge of pavement structure and its relationships to key distresses and performance, in addition to advanced traffic studies, sensitivity analysis, and local distress models calibration are required. For that purpose, implementation initiatives were laid out by the Indiana Department of Transportation (INDOT). Presented in this paper are investigative studies, sensitivity analyses, and implementation initiatives conducted by INDOT for each design module in the M-E Design Guide
     Tommy E. Nantung, Indiana Department of Transportation, tnantung@indot.in.gov
     Ghassan R. Chehab, American University of Beirut, Lebanon
     Scott  Newbolds, Benedictine College
     Khaled  Galal, Engineering and Research International
     Shuo  Li, Indiana Department of Transportation
     Daehyeon  Kim, Chosun University, South Korea

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05-1414 - Comprehensive Approach for Development of Performance Models for Network-Level Pavement Management System Using LTPP Data
Session 369
Pavement Performance models are a key component of any Pavement Management system (PMS). Development of these models for a network-level PMS has been traditionally based on historical performance and inventory data. However, historical data may represent a challenge for the highways agencies, due to continuous upgrades in field data collection equipment and the possible incompleteness of inventory records. The Long Term Pavement Performance (LTPP) database can provide an alternate reliable source of data for the development of pavement performance models. LTPP data can be tailored to fit the scope of a PMS and used through a PMS approach for the development of base pavement performance models. These base models can then be adjusted to agency-specific experience and/or data to produce agency-specific models. In this paper, a mechanism for the development base pavement performance models in the context of a pavement management application is presented. As a case study to demonstrate this approach, IRI performance models for flexible pavements in different environmental zones are developed using data from LTPP SPS-5 test sites. The developed models successfully represented the expected general performance trends in term of the differential performance among rehabilitation activities and environmental zones. Models representing freezing environmental zones seemed to deteriorate faster than those developed for no-freeze environmental zones. Also performance models for thinner AC overlay rehabilitation activities seemed to deteriorate faster that those of the thicker AC overlay activities. State-specific data can then be used for final calibration and verification of these models.
     Wael  Bekheet, Alexandria University, Egypt, wbekheet@gmail.com
     Khaled  Helali, Stantec Consulting, Inc.
     Halim Omar Abd El Halim, Carleton University, Canada
     Jack H. Springer PE, Federal Highway Administration

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05-1422 - Forensic Analysis of Slippage Cracking
Session 541
Premature pavement failure is costly to agencies and disturbing to the traveling public. This paper discusses slippage cracking which occurred shortly after construction affecting about half of the overlay project length. This article offers a comparative analysis based on the review of quality control information, performance testing of the hot mix asphalt using the Superpave shear tester (SST), in situ evaluation of the unbound layers using the dynamic cone penetrometer (DCP) and computed surface deflections. A great emphasis was placed on the evaluation of the mix properties because of the perceived lack of mix cohesion when visually examining the damaged pavement. Performance testing of field cores indicated that the hot mix from the section with cracking performed similarly in terms of stiffness and slightly better in terms of accumulated permanent strain than the hot mix from the section without cracking demonstrating that the cause of the problem was not related to hot mix asphalt properties. Testing of laboratory samples prepared with various binders also confirmed the superior properties of the polymer-modified asphalt used on the project. The results of this study showed that the DCP curves were significantly different between the sections with and without slippage cracking. Estimated surface deflections were higher for the areas which had slippage cracking. An empirical relationship was used to estimate equivalent single axle loads (ESAL’s) to failure from surface deflection showing that it would take less traffic for the section that had slippage cracking to fail when compared to the section without cracking.
     Stephane  Charmot P.E., SemMaterials Company, SCharmot@semgrouplp.com
     Pedro  Romero, University of Utah
     Michael  Dunning P.E., Clark County Department of Public Works

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05-1481 - Pavement Management System Based on Financial Consequence
Session 233
One of the biggest challenges that any public organization is concerned with is how to prioritize projects to maximize the existing funding. Today, with so many programs competing for the same funding, it is more important than ever to optimize the pavement rehabilitation program in order to allow funding for other programs such as safety, capacity improvements, and environmental improvement projects. The objective of this report is to describe how the Nevada Department of Transportation (NDOT) optimized its available funding while improving pavement condition using an eight step financial consequence-based pavement management system. This eight step procedure includes administration support, contract database implementation, roadway system division, performance models, project prioritization, and strategy selection. This procedure can easily be adopted by other states. A nominal amount of information is required to initiate this financial consequence-based system and the reward can be exceptional. NDOT saves $42M per year using this methodology. Another advantage of a financial consequence-based pavement management system over a conventional network optimization system is that this process allows engineers to communicate with top administration in a very nontechnical way. Administrators can understand the concept and make the right roadway funding choices without needing a great deal of technical input from engineers. For example, administration understands that the cost of delaying a 10-mile roadway section on an interstate system by two years can cost the agency an additional $6M for rehabilitation. However, a financial consequence of delaying a 10-mile roadway section on a relatively low volume road might be only a few thousand dollars.
     Sohila  Bemanian, Parsons
     Patricia L. Polish, Nevada Department of Transportation
     Gayle  Maurer, Nevada Department of Transportation, gmaurer@dot.state.nv.us

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05-1511 - Maintenance and Rehabilitation of Low-Volume Pavements in Washington State
Session 336
The vast majority of pavements worldwide can be classified as low-volume. Pavement maintenance and rehabilitation practices on these roads are vital to their continued serviceability. Proven successful and efficient strategies are in demand considering that low-volume roads are typically managed by agencies with extremely limited resources. The Washington State Pavement Management System (WSPMS), which has been functioning continuously for over 30 years, provides a rich data set from which to investigate maintenance and rehabilitation practices on low-volume pavements in Washington State. This investigation seeks to determine common maintenance, rehabilitation, design and material characteristics in WSDOT managed low-volume pavements and measures of their success. Records indicate that over two-thirds of WSDOT’s low-volume pavements are bituminous surface treatments, while almost one-third are hot mix asphalt surfaced pavements. These pavements, many of which have lasted in excess of 35 years, are in relatively good condition and are typically subject only to periodic rehabilitation treatments every 8 to 20 years and responsive pothole patching. This evidence suggests that the concept of a long-lasting low-volume pavement is viable and, in fact, already exists. More study is required to determine the physical, construction and preservation principles behind this phenomenon.
     Stephen T. Muench, University of Washington, stmuench@uw.edu
     George C. White, University of Washington
     Joe P. Mahoney, University of Washington
     Nadarajah  Sivaneswaran, Federal Highway Administration
     Linda M. Pierce, Applied Pavement Technology, Inc.

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05-1658 - Rut Initiation Mechanisms in Asphalt Mixtures as Generated Under Accelerated Pavement Testing
Session 708
The Florida Department of Transportation (FDOT) conducted an experiment to address the effects of polymer modifiers on the performance of Superpave mixes using a Heavy Vehicle Simulator (HVS). Two fine-graded Superpave mixes were considered. One mix included a virgin binder meeting the requirements of PG 67-22, while the other contained a SBS polymer-modified binder meeting those of PG 76-22. Both respective mixes contained the same effective binder content, aggregate components and gradation. The mixes were designed for 10-30 million ESALs, using the standard Superpave mix design methodology. During placement of these mixes, all standard FDOT density requirements and acceptance criteria were applicable. The subsequent investigation showed that the sections with SBS-modified mixture significantly outperformed those with the unmodified mixture. It was also determined that rutting in the unmodified mixture was primarily a function of shear flow while rutting in the SBS-modified mixture was due mainly to densification. This paper presents a description of the testing program, the data collection effort and the subsequent analyses and findings focusing primarily on the initiation mechanisms of rutting in asphalt mixtures as generated and observed under accelerated pavement testing.
     Salil  Gokhale, Dynatest Consulting, Inc., sgokhale@dynatest.com
     Bouzid  Choubane, Florida Department of Transportation
     Thomas  Byron, Florida Department of Transportation
     Mang  Tia, University of Florida

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05-1675 - Use of Pavement Management System Data to Monitor Performance of Pavements Under Warranty
Session 297
Pavement warranty is an innovative contracting procedure that has been adopted by more and more highway agencies in recent years. Many states view implementing warranties as a method to protect their investment in pavement construction. The major benefit of pavement warranty is the enhanced pavement performance. However, establishing warranty criteria and monitoring the performance of warranted pavement are two technical issues that need to be resolved. This paper presents the discoveries of a research project supported by Federal Highway Administration (FHWA) to investigate the effectiveness of using the Pavement Management System (PMS) to monitor the performance of pavement under warranty. Based on the history and experience of pavement warranty, warranty specifications, performance indicators, data collection method, and available data in the PMS, five states, Indiana, Wisconsin, Ohio, Florida, and Michigan, were selected for this study. It has been discovered that most states establish their warranty specifications based on the performance data from their PMS database using statistical analyses, expert opinions and adaptation of the specifications of other states. They also use the PMS data to monitor the performance of both warranty and non-warranty pavements because the essential data like ride, cracking, rutting etc. are available in the database and convenient for use. This paper also documents the unique features of the warranty specifications including the warranty period, performance indicators, data collection methods, performance thresholds, remedial actions, and how PMS database can be used to track the performance of pavements under warranty in the five selected states. Some comparisons between the performances of the warranted pavements and those of non-warranted pavements of similar conditions are also presented. The survey indicated that an integrated PMS that links the materials and traffic database would offer better efficiency to monitor and analyze the performance of both warranty and non-warranty pavements.
     Linbing  Wang, Virginia Polytechnic Institute and State University, wangl@vt.edu

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05-1688 - Unbound Aggregate Rutting Models for Stress Rotations and Effects of Moving Wheel Loads
Session 723
This paper presents the latest research findings on stress rotations due to moving wheel loads and their effects on permanent deformation or rut accumulation in pavement granular layers. Realistic pavement stresses induced by moving wheel loads were examined in the unbound aggregate base and subbase layers and the important effects of rotation of principal stress axes were indicated for a proper characterization of the permanent deformation behavior. To account for the rutting performances of especially thick granular layers, a comprehensive set of repeated load triaxial tests were conducted in the laboratory. Triaxial test data were obtained and analyzed from testing aggregates under various realistic in-situ stress paths due to moving wheel loading. Permanent deformation characterization models were then developed based on the experimental test data to include the static and dynamic stress states and the slope of stress path loading. The models that also considered the stress path slope variations predicted best the stress path dependency of permanent deformation accumulation. In addition, multiple stress path tests conducted to simulate the extension-compression-extension type rotating stress states under a wheel pass gave much higher permanent strains than those of the compression only single path tests. The findings indicated actual traffic loading simulated by the multiple path tests could cause greater permanent deformations or rutting damage especially in the loose base/subbase when compared to deformations measured from a dynamic plate loading or a constant confining pressure type laboratory test.
     In Tai  Kim, University of Illinois, Urbana-Champaign
     Erol  Tutumluer, University of Illinois, Urbana-Champaign, tutumlue@illinois.edu

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05-1779 - Thaw Weakening Mitigation of Unpaved Roads in Vermont
Session 642
We evaluated the performance of several techniques thought to mitigate deterioration of unpaved roads during spring thaw. Each potential remedy was aimed at providing some combination of limiting the availability of moisture in the winter, improving drainage during spring and strengthening the upper portion of the road. With one exception, each technique implemented uses locally and/or commercially available materials and all were easy to construct, i.e., a town road crew could build it. Construction was followed by two seasons of monitoring. We compared the percentage of the road covered in ruts and strength estimates based on dynamic cone penetrometer values for treated and control sections. Methods that either 1) permanently improved the strength of the top 12 inches of the road or 2) decreased the water content of the upper 12 inches of the road resulted in significant performance improvement during spring thaw.
     Karen S. Henry PhD, United States Air Force Academy, Karen.Henry@usafa.edu
     James P. Olson, University of Vermont
     Stephen P. Farrington, Transcendev
     Christopher C Benda, Vermont Agency of Transportation
     John  Lens, GeoDesign Inc.

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05-1880 - Evolution of Pavement Winter Roughness
Session 603
The functional service level of roads is quantified in terms of roughness. This parameter considers every road surface defect causing passenger vehicle discomfort. Roughness is measured using a quality index, the IRI (International Roughness Index). Roughness gives an overall appreciation of road profile quality without, however, permitting a deeper analysis. In fact, the overall value of the IRI does not discriminate between the two main factors responsible for winter deterioration of roughness, the first being the subgrade differential heave and the second being heave cracks. Differential heave is obtained from the variability in frost susceptibility of subgrade. This phenomenon, which occurs deep in the subgrade, is detectable by isolating the long wave lengths produced at the road surface from the longitudinal profile. Heave cracks are a superficial phenomenon greatly influenced by the application of de-icing salts. By isolating the short wave lengths from the profile, it is possible to highlight the influence of this phenomenon on deterioration. The goal of this research is therefore to establish, using a filtering technique of road profile, the contribution of these two main factors to winter deterioration of roughness on five road sections in the Québec City area. This study will then allow the development of a tool to determine the dominant factor for deterioration and therefore the use of the best technique to rehabilitate roads.
     Nicolas  Fradette, No Organization
     Pascale  Pierre, Laval University, Canada, ppierre@gci.ulaval.ca
     Guy  Doré, Universite Laval, Canada
     Serge  Hébert, Laval University, Canada

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05-1888 - Implementing the Mechanistic-Empirical Design Guide Procedure for a Hot-Mix Asphalt-Rehabilitated Pavement in Indiana
Session 572
One of INDOT’s strategic goals is improving its pavement design procedures. This goal can be accomplished by the full implementation of the 2002 M-E design guide once it is approved by AASHTO. The release of the M-E 2002 software has provided a unique opportunity for INDOT engineers to evaluate, calibrate, and validate the new M-E design process. A CRC pavement on I-65 was rubblized and overlaid with a 13” thick HMA overlay in 1994. The availability of the structural design, material properties, climatic and traffic conditions in addition the availability of performance data provided a unique opportunity for comparing the predicted performance of this section using the M-E procedure with the in-situ performance, with calibration efforts being conducted subsequently. This paper discusses the 1993 design of this pavement section and comparison with the 2002 M-E design and predicted performance using the same design inputs. In addition, design levels and inputs were varied to achieve the following: a) assess the functionality of the M-E 2002 Design Guide software and the feasibility of applying M-E design concepts for structural pavement design of Indiana roadways b) determine the sensitivity of the design parameters and the input levels that are most critical to the 2002 M-E predicted distresses and its impact on the implementation strategy that would be recommended to the INDOT and c) evaluate the rubblization technique that was implemented on the I-65 pavement section. Finally, an example calibration of the rutting model is provided.
     Khaled  Galal, Engineering and Research International, khaled.galal@eri_rgme.com
     Ghassan R. Chehab, American University of Beirut, Lebanon

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05-1912 - Incorporating Variability into Pavement Performance, Life-Cycle Cost Analysis, and Performance-Based Specification Pay Factors
Session 297
This paper describes a recent research study that examined how changes in design life impacts the pavement life cycle cost (LCC) and ultimately how the reduction or addition in LCC attributed to inferior or superior in-service performance could be used as a basis for establishing a pay factor for a performance based specification. Models have been developed using data from the Canadian Long Term Pavement Performance (C-LTPP) that indicate that overlay thickness, total prior cracking, annual freeze index, annual days with precipitation, and accumulated ESALs after eight years, affect the slope of pavement deterioration for asphalt overlay pavements. One of these models, as well as data from the United States Long Term Pavement Performance (LTPP) test sites, is used to determine the service life of asphalt overlay pavements. This paper examines how the variability associated with overlay thickness, total prior cracking, and accumulated ESALs after eight years affects the service life. Furthermore, this paper considers the variability associated with the discount rate and incorporates all associated variability into the life cycle cost analysis (LCCA). The life cycle cost distributions are calculated using Monte Carlo techniques. Based on a recent study, distributions for service life and life cycle costs are developed using both the normal and lognormal distributions for overlay thickness. Using the LCCA values for typical design lives, a sensitivity analysis is subsequently performed to evaluate the impact of 10%, 20% and 30% differences in the in-service performance as compared to the design life. These LCCA differences are then used as a basis for establishing pay factors. Overall the paper attempts to relate design to in-service performance LCC and ultimate use of pay factors. Key words: pavement performance, life cycle cost analysis, asphalt overlay, pay factors.
     Leanne Claire Whiteley BASc, University of Waterloo, Canada, leannewhiteley@alumni.uwaterloo.ca
     Susan Louise Tighe, University of Waterloo, Canada

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05-1951 - Development of Surfacing Criteria for Low-Volume Roads in South Dakota
Session 336
On a daily basis, local road agencies in South Dakota face the challenge of how to cost-effectively maintain low-volume roads. Specifically, agencies are faced with the decision of determining when it is most economical to maintain, upgrade, or downgrade a road’s existing surface. In order to assist decision makers with these types of maintenance and rehabilitation decisions, the South Dakota Department of Transportation (SDDOT) initiated a research study in 2002 to investigate surfacing criteria for low-volume roads (LVR). The overall objective of this research study is to create a process that allows the user to compare the costs associated with different types of roads to provide assistance in deciding which surface type (hot-mix asphalt [HMA], blotter, gravel, or stabilized gravel) is most economical under a specific set of circumstances. In addition to incorporating economic factors into the analysis, the process allows the user to consider other non-economic factors that are more subjective and difficult to quantify. The process used during this study is flexible enough to allow users to consider any combination of agency costs incurred by the agency for maintaining its roads, non-agency (user) cost factors such as vehicle operating costs or crash potential, and non-economic factors such as politics and housing densities. The methodology was created using agency cost and user cost models that were developed based upon specific road section information supplied by various local agencies in South Dakota, average daily traffic (ADT) and crash occurrence information supplied by the SDDOT, information obtained through a literature search, and input from members of the project’s Technical Panel.
     Angela S. Wolters, Applied Pavement Technology, Inc.
     Kathryn A. Zimmerman P.E., Applied Pavement Technology, Inc., kzimmerman@appliedpavement.com
     David L. Huft, South Dakota Department of Transportation
     Paul A. Oien, South Dakota Department of Transportation

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05-2038 - Study of Problematic Silt Stabilization
Session 483
Soils with high silt content are a common occurrence and can raise widespread road construction and performance problems due to their low strength, minimal bearing capacity and highly moisture susceptibility. Their stability is greatly influenced by the degree of densification achieved during compaction. Problematic silts subjected to high compaction energies develop pumping phenomenon, especially when the soil is wet of optimum. The strength and stiffness of silty-subgrade soils is also greatly reduced when moisture infiltrates the compacted soil due to capillary action during post construction period. Moisture susceptibility is an important factor that affects the mechanical properties of subgrade materials. This paper presents a study regarding the identification and stabilization of problematic silts. The characteristics of a set of three soils with a high potential to pump are investigated. Conditions generating pumping phenomenon are duplicated in the laboratory by a set of cyclic triaxial tests. In addition to the high silt content, the plasticity character and moisture susceptibility are noted as significant factors for pumping. The potential for the stabilization of problematic silts with Portland cement and lime is also studied. The percentages of additives are considered based on strength criteria and the evolution of moisture susceptibility of the subgrade material is investigated using Tube Suction Test. The results demonstrate Portland cement represents the most effective chemical additive for the soils considered in this study. This paper demonstrates the relevance of moisture susceptibility criteria as an important consideration in the design specifications for subgrade stabilization.
     Bogdan George Barbu, Texas A&M Transportation Institute , b-barbu@tamu.edu
     Kenneth  McManis, University of New Orleans

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05-2081 - Asphalt Pavement Rehabilitation Treatment: Analysis of 20 Years of Performance
Session 571
The Pennsylvania DOT Engineering District in northwestern Pennsylvania experienced very poor pavement conditions in the early 1980’s. Several methods of pavement rehabilitation of asphalt-surfaced highways were utilized to improve pavement performance, and management of pavement investment. This paper analyzes the performance of a number of these sections after twenty-one years. Results from the analysis show that relative to conventional mill and level with overlay, the appropriate application of stress absorbing membrane interlayers (SAMI) and cold in-place recycling has been very effective in both performance and relative cost effectiveness. The analysis also shows that for a subsequent generation of rehabilitation, the benefit of these treatments continues to be evident. As a result of this study, it is recommended that highway owners seriously evaluate other rehabilitation treatments than conventional mill and level with overlay. The performance of SAMI and cold recycled sections in this instance has more than justified the additional expense of the construction. Key words: pavement rehabilitation, cold recycling, stress absorbing membrane interlayer
     Dennis A. Morian, Quality Engineering Solutions, Inc., dmorian@qespavements.com
     Yanqing  Zhao Ph.D., Quality Engineering Solutions, Inc.
     Janice L. Arellano, Pennsylvania Department of Transportation
     Donald E. Hall, Pennsylvania Department of Transportation

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05-2135 - Prediction of Long-Term Minimum Concrete Temperature Using Climatic Variables
Session 263
Research findings have shown that concrete pavement temperature changes with depth. The most critical temperature changes take place at the top of the slab, where different factors combine causing high tensile stresses. A different condition has been observed for the mid-depth of the slab, where concrete temperature differentials are not too critical over time. This situation makes one think that although current concrete pavement thickness designs might be appropriate, reinforcement steel might be overdesigned. The Center for Transportation Research (CTR) at The University of Texas at Austin has performed extensive research in the area of concrete pavement evaluation. For design purposes, pavement instrumentations have shown that the effect of ambient temperature is more critical at the top of the pavement slab than at mid-depth and bottom locations. Field experiments have been conducted to monitor the evolution of concrete temperature for the short and long terms. A series of portland cement concrete pavement (PCCP) sections in various locations in Texas have been instrumented and temperature histories have been recorded using i-Buttons. This investigation intends to present the findings from this research and proposes a methodology that can be used for estimating the minimum concrete temperature for pavement design. The material presented here shows that concrete pavement temperature values are not as low as thought, which causes overdesigned steel contents. These ideas will provide valuable information and a positive step towards the standardization of the application of PCCP anywhere.
     Cesar Ivan Medina, Transtec Group, Inc., cesar@thetranstecgroup.com

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05-2189 - Quantification of Pavement Damage Caused by Dual and Wide-Base Tires
Session 708
A study conducted in 2000 on the heavily instrumented Virginia Smart Road measured pavement responses to a new generation of single wide-base tire and to dual tires. The investigated new single wide-base tire has a wider tread and a greater load-carrying capacity than the conventional wide-base tire. The potential fatigue damage resulting from different tire configurations was also evaluated. After successful field-testing, a finite element (FE) parametric study was conducted to investigate different failure mechanisms that were not evaluated in the field. In this study, dual tires and two new generations of wide-base tires were investigated. The main differences between the first and second generation of wide-base tire is that the second is wider than the first; hence, it further reduces the contact stress at the pavement surface under the same nominal tire pressure. In the developed FE models, geometry and dimensions were selected to accurately simulate the axle configurations typically used in North America; actual tire tread sizes and applicable contact pressure for each tread were considered; laboratory-measured pavement material properties were incorporated; and models were calibrated and properly validated against stress and strain measurements obtained from the experimental program. Four failure mechanisms were considered: fatigue cracking, primary rutting, secondary rutting, and top-down cracking. Results indicated that the first new generation of single wide-base tire would cause relatively greater pavement damage than conventional dual tires. On the other hand, the second size new generation of wide-base tire would induce similar pavement damage as the conventional dual tires.
     Mostafa A. Elseifi, Louisiana State University
     Imad L. Al-Qadi, University of Illinois, Urbana-Champaign, alqadi@illinois.edu
     Pyeong Jun  Yoo, Korea Institute of Construction Technology
     Ibrahim  Janajreh, Michelin Americas R&D Corporation

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05-2202 - Application of Reliability Concept in Concrete Pavement Rehabilitation Decision Making
Session 679
ABSTRACT The application of reliability analysis during pavement design is essential to understand the effect of variability on the quality pavements that serve the traveling public in a comfortable and safe manner. As well as being durable in service, these pavements must have minimum life cycle costs (LCCs). Strategic Analysis of Pavement Evaluation and Repair (SAPER) software Version 2.0 is an analysis tool developed on the behalf of the Federal Highway Administration (FHWA) to assist in the evaluation and selection of appropriate strategies for maintenance, rehabilitation, and reconstruction (MRR) of concrete pavements at the project level, where design reliability is incorporated through a decision making process (DMP). In this paper current practice for including reliability concepts in the SAPER software are presented which addresses the reliability approach used in the DMP, and pavement life extension prediction with respect to varied distress models and associated LCCs that incorporate reliability analysis for candidate MRR strategies. It shows that the reliability approach used in the DMP provides a simple, practical and precise way to take into account the variability of the factors that control the pavement performance. Results of typical pavement strategy selection examples with varied reliability parameters indicate that the reliability parameters play an important role, and must be considered through the MRR strategy selection. Key words: Reliability, Repair, Rehabilitation, Concrete Pavements, Strategy, DMP
     Juanyu  Liu Ph.D., University of Alaska, Fairbanks, jliu6@alaska.edu
     Dan G. Zollinger, Texas A&M University
     Shiraz  Tayabji, Applied Research Associates, Inc.
     Kurt D. Smith P.E., Applied Pavement Technology, Inc.

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05-2381 - Analysis of Long-Term Effectiveness of Thin Hot-Mix Asphaltic Concrete Overlay Treatments
Session 297
ABSTRACT Thin hot mix asphaltic concrete (HMA) overlays are preventive maintenance treatments used to address minor distresses, increase ride quality, and extend pavement life. This paper determines the long-term effectiveness of such treatments using three measures of effectiveness – treatment service life, increase in average pavement condition, and area bounded by the performance curve. For each measure of effectiveness, the pavement performance indicators used are International Roughness Index (IRI), Rutting, and Pavement Condition Rating (PCR). For each measure of effectiveness and performance indicator, treatment benefits were found to lie within a wide range due to the effect of varying levels of weather severity, traffic, and route type. The service life of the treatment ranges from 3-13 years (on the basis of IRI performance indicator), 3-14 years (for rutting) and 3-24 years (for PCR). When the increase in average pavement condition is used as the measure of effectiveness, the results show that such treatments offer 18-36% decrease in IRI, 5-55% reduction in rutting, and 1-10% increase in PCR. In terms of area enclosed by the performance curve, thin HMA overlay effectiveness ranges from 40 to 360 IRI-years (where IRI is in in/mile), 0.13-0.76 RUT-years (where RUT is in inches), and 7-130 PCR-years (where PCR is on a 0-100 scale). The wide ranges of thin HMA overlay effectiveness for each combination of measure of effectiveness and performance indicator is suggestive of the sensitivity of the treatment effectiveness to levels of traffic loading and weather severity, and route type. The effectiveness of thin HMA overlay treatments is of interest to pavement professionals and is a vital input in the quest for cost-effective long-term pavement preservation practices.
     Samuel  Labi, Purdue University, labi@purdue.edu
     Geoffrey  Lamptey P.E., Corzo Castella Carballo Thompson Salman, P.A.
     Sravanthi  Konduri, Oak Ridge National Laboratory
     Kumares C. Sinha, Purdue University

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05-2524 - Early-Age Strength Assessment of Cement-Treated Base Material
Session 411
In order to avoid early-age damage to cement-treated base (CTB) materials, the cement must be allowed to cure for a period of time before the pavement can be opened to traffic. The purpose of this research was to evaluate the utility of the soil stiffness gauge (SSG), heavy Clegg impact soil tester (CIST), dynamic cone penetrometer, and falling-weight deflectometer for assessing early-age strength gain of cement-stabilized materials. Experimentation was performed at four sites on a pavement reconstruction project along Interstate 84 in Morgan, Utah, in which cement stabilization was used in conjunction with full-depth recycling. Each site was stationed to facilitate repeated measurements at the same locations with different devices and at different curing times. Because of the considerable attention they have received in the pavement construction industry for routine quality control and quality assurance programs, the SSG and CIST were the primary focus of the research. Statistical techniques were utilized to evaluate the repeatability of these devices and their sensitivity to curing time. The results indicated that while the SSG was more repeatable at one site, the CIST data were markedly more sensitive to curing time than the SSG data at all of the cement-treated sites during the first 72 hours after construction. For this reason, the data suggest that the CIST offers greater overall utility than the SSG for monitoring early-age strength gain of CTB. Further research is needed to investigate appropriate thresholds and protocols for these testing methods that ensure adequate reliability of the collected data.
     W. Spencer Guthrie, Brigham Young University, guthrie@byu.edu
     Tyler B. Young, Brigham Young University
     Brandon James Blankenagel, City of Spokane
     Dane A. Cooley, Kimley-Horn & Associates, Inc.

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05-2690 - Can Spring Load Restrictions on Low-Volume Roads Be Shortened Without Increasing Road Damage?
Session 484
Major highways are designed to withstand heavy vehicles and high volumes of traffic year round. However, low volume roads in seasonal frost areas are highly susceptible to damage from trafficking by heavy vehicles during spring thaw. Conventional practice is to place partial or full spring load restrictions on low volume roads during spring thaw. This practice will reduce damage significantly. However, companies whose livelihood depends on trucking can suffer major economic losses as they await removal of load restrictions. Using reduced tire pressure constitutes a less conventional road usage technique that can also contribute toward reducing springtime damage. Reducing tire pressure generally appears to be less effective than reducing load. Nevertheless, it does appear that the load restriction window can be reduced in duration by implementing a reduction in tire pressure for a short duration starting toward the latter part of the standard spring load restriction. Using a mechanistic pavement design and evaluation model for seasonal frost areas that had been under development by the US Army Corps of Engineers, this paper discusses the development of a critical combination of load and tire pressure reduction that contributes toward optimizing the balance between minimizing springtime road damage and minimizing disruption to local economies caused by load restrictions.
     Maureen A. Kestler, USDA Forest Service, mkestler@fs.fed.us
     Richard L. Berg, FROST Associates
     John E. Haddock, Purdue University

Roadway Pavement Preservation

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05-0348 - Guidelines for Prime Coat Usage on Low-Volume Roads
Session 336
Prime coat has a purpose in the pavement construction process, yet many times prime is misused or eliminated during the project. While most of the time no harm appears to occur to the roadway and thus may be viewed as acceptable, technical guidance is warranted to assure appropriate usage. The objective of this study was to produce a prime coat guide publication developed for Central Federal Lands Highway Division (CFLHD) project development and field personnel to provide decision-making guidance on how to use, when to keep, and when to eliminate prime coat. The literature search, which focused on handbooks and technical reports, was conducted along with a review of agency construction specifications. A phone survey of current practice of state DOTs from the region was undertaken to provide information on current practice. Finally, a review of the potential harmful and positive environmental effects of the prime coat process, including the various bituminous products used, was undertaken. Based on the information collected, a guideline for project development and field personnel was developed. The guideline provides decision-making guidance on how to use, when to keep, and when to eliminate prime coats.
     Stephen  Cross, Oklahoma State University, steve.cross@okstate.edu
     Michael David Voth, Federal Highway Administration
     Pramed P Shrestha, Oklahoma State University

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05-0508 - Field Evaluation of Porous Friction Course for Noise Control
Session 480
In 2003, the Indiana Department of Transportation allowed a test section of Porous Friction Course (PFC) to be placed on I74 east of Indianapolis. This paper summarizes the design, construction and early performance of that surface compared to an adjacent SMA surface and a conventional Superpave HMA surface. All three mixes included steel slag aggregate and a PG76-22 binder. The PFC was designed at 18-22% air voids to provide a permeable surface. Noise measurements were made on all three surfaces using both the pass-by and close-proximity methods. The three surfaces were also evaluated in terms of surface texture using the Circular Texture Meter and friction using the Dynamic Friction Tester and towed friction trailer. Splash and spray were judged qualitatively. The early performance indicates that the PFC produced significantly lower noise levels, higher surface texture and friction, and reduced splash and spray compared to the other two surface types.
     Rebecca S. McDaniel, Purdue University, rsmcdani@purdue.edu
     William D. Thornton, Purdue University

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05-0861 - Effect of Density and Mixture Proportions on Freeze-Thaw Durability of Roller-Compacted Concrete Pavement
Session 702
Roller-compacted concrete (RCC) is widely used for industrial and heavy duty pavements. It is an economical and durable material for paving and other applications. RCC has relatively high strength and density. Although the strength of RCC has been thoroughly investigated, the freeze-thaw durability of RCC remains a topic of contention. RCC has often performed well in harsh field environments, but it often fails laboratory freeze-thaw durability testing. In this study, 24 specimens were fabricated for freeze-thaw durability testing using a gyratory compactor. Study variables were degree of compaction, amount of water, and water/cement (w/c) ratio (and hence, also, amount of cement). Specimens replicated typical RCC pavement and dam construction. The RCC specimens were subjected to up to 300 cycles of rapid freezing and thawing, and were tested for fundamental transverse frequency and mass loss. Due to the low aspect ratio of the specimens, fundamental transverse frequency testing was not reliable. Several specimens completed the 300 cycles with mass loss of less than 10 %. The freeze-thaw durability of RCC was found to be dependent primarily on the amount of cement paste and w/c ratio, and to a lesser extent on degree of compaction.
     Norbert Joseph Delatte, Cleveland State University, n.delatte@csuohio.edu
     Chris  Storey, University of Alabama, Birmingham

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05-1511 - Maintenance and Rehabilitation of Low-Volume Pavements in Washington State
Session 336
The vast majority of pavements worldwide can be classified as low-volume. Pavement maintenance and rehabilitation practices on these roads are vital to their continued serviceability. Proven successful and efficient strategies are in demand considering that low-volume roads are typically managed by agencies with extremely limited resources. The Washington State Pavement Management System (WSPMS), which has been functioning continuously for over 30 years, provides a rich data set from which to investigate maintenance and rehabilitation practices on low-volume pavements in Washington State. This investigation seeks to determine common maintenance, rehabilitation, design and material characteristics in WSDOT managed low-volume pavements and measures of their success. Records indicate that over two-thirds of WSDOT’s low-volume pavements are bituminous surface treatments, while almost one-third are hot mix asphalt surfaced pavements. These pavements, many of which have lasted in excess of 35 years, are in relatively good condition and are typically subject only to periodic rehabilitation treatments every 8 to 20 years and responsive pothole patching. This evidence suggests that the concept of a long-lasting low-volume pavement is viable and, in fact, already exists. More study is required to determine the physical, construction and preservation principles behind this phenomenon.
     Stephen T. Muench, University of Washington, stmuench@uw.edu
     George C. White, University of Washington
     Joe P. Mahoney, University of Washington
     Nadarajah  Sivaneswaran, Federal Highway Administration
     Linda M. Pierce, Applied Pavement Technology, Inc.

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05-1766 - Comparison of Thin-Lift Hot-Mix Asphalt Surface Course Mixes in New Jersey
Session 480
The use of thin-lift HMA surface course mixes is starting gaining wide acceptance in the United States as a means of improving both ride quality and safety. These materials are generally classified as having an open-graded/gap-graded aggregate skeleton, nominal aggregate sizes of 12.5mm or less, higher than normal asphalt binder contents, and are placed in thickness’ less than one inch. The use of the thin-lift materials has found to improve wet weather driving conditions, reduce traffic noise associated with the tire/pavement interface, and improve the ride quality measurements. Thin-lift HMA surface course mixes typically found in New Jersey consist of open-graded friction courses (OGFC) and Novachip®, with a few roadway sections using micro-surfacing and stone-mastic asphalt (SMA). Each of these material types were evaluated to provide an assessment of their ride quality and safety. These thin-lift materials were compared to in-service dense-graded asphalt mixes (DGA) and Portland cement concrete (PCC). The PCC had surfaces that consisted on no treatment, transverse tined, and diamond grind. Noise measurements utilizing the Close Proximity method (CPX), wet skid resistance, and ride quality data consisting of RQI and IRI were used to establish “performance” comparisons between the different surface courses. The “performance” information, along with current costs associated with the materials and construction, can provide a means of establishing a cost-effectiveness for utilizing these surface treatments under specific situational conditions.
     Thomas A. Bennert, Rutgers University, bennert@rci.rutgers.edu
     Frank  Fee, Asphalt Pavement Technology, LLC
     Eileen C. Sheehy, New Jersey Department of Transportation
     Andris A. Jumikis PE, New Jersey Department of Transportation
     Robert W. Sauber, Consultant

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05-1951 - Development of Surfacing Criteria for Low-Volume Roads in South Dakota
Session 336
On a daily basis, local road agencies in South Dakota face the challenge of how to cost-effectively maintain low-volume roads. Specifically, agencies are faced with the decision of determining when it is most economical to maintain, upgrade, or downgrade a road’s existing surface. In order to assist decision makers with these types of maintenance and rehabilitation decisions, the South Dakota Department of Transportation (SDDOT) initiated a research study in 2002 to investigate surfacing criteria for low-volume roads (LVR). The overall objective of this research study is to create a process that allows the user to compare the costs associated with different types of roads to provide assistance in deciding which surface type (hot-mix asphalt [HMA], blotter, gravel, or stabilized gravel) is most economical under a specific set of circumstances. In addition to incorporating economic factors into the analysis, the process allows the user to consider other non-economic factors that are more subjective and difficult to quantify. The process used during this study is flexible enough to allow users to consider any combination of agency costs incurred by the agency for maintaining its roads, non-agency (user) cost factors such as vehicle operating costs or crash potential, and non-economic factors such as politics and housing densities. The methodology was created using agency cost and user cost models that were developed based upon specific road section information supplied by various local agencies in South Dakota, average daily traffic (ADT) and crash occurrence information supplied by the SDDOT, information obtained through a literature search, and input from members of the project’s Technical Panel.
     Angela S. Wolters, Applied Pavement Technology, Inc.
     Kathryn A. Zimmerman P.E., Applied Pavement Technology, Inc., kzimmerman@appliedpavement.com
     David L. Huft, South Dakota Department of Transportation
     Paul A. Oien, South Dakota Department of Transportation

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05-2566 - Road to Quiet Neighborhoods in Arizona
Session 480
The Arizona Quiet Pavement Pilot Program (QP3) is a $34 million project implemented to reduce highway related traffic noise. This pilot program represents the first time that pavement surface type has been allowed as a noise mitigation strategy on federally funded projects. The program will overlay most of the Phoenix metropolitan area PCCP with one inch of ARFC. As a condition of using pavement type as a mitigation strategy, ADOT developed a ten-year, $2 million research program to evaluate the efficacy of using ARFC. Historically, pavement surface type was not considered a permanent solution due to the change in acoustic properties with time. This research program will evaluate the change in pavement acoustic properties through three means, (1) conventional roadside testing (eg far field measurements), (2) the use of near field measurements, both Close Proximity (CPX) and Sound Intensity (SI), and (3) far field measurements taken within the surrounding neighborhoods. This paper provides an overview of the program development, presents the research conducted to support the decision to overlay the urban freeway, and the status of current research. Particular emphasis is placed on the development and use of near field measurement systems consisting of CPX and SI Preliminary results from the research to date indicate that the near field measurement systems are providing meaningful assessments of pavement acoustic performance and the SI and CPX methods compare favorably. The overlays placed reduce the near field measurement levels between 6 to 11 dBA. Average reductions of 5 dBA occurred in the neighborhoods.
     Larry A. Scofield, International Grooving and Grinding Association, lscofield@pavement.com
     Paul  Donavan, Illingworth & Rodkin, Inc.

Safety

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05-0326 - Axle and Wheel Loads in Developing Countries and Consequences for Material Specifications
AFB30
Overloading of trucks is a serious problem in developing countries. It results in high axle and wheel loads which have a devastating effect on the pavement structure. It is common practice to express the damaging effect in terms of an equivalent number of standard axle loads. The question arises whether this is a useful approach in case of overloaded trucks. The reason for this doubt is because of the fact that due to poor maintenance of the trucks, improper loading etc, wheel loads might occur which are much higher than the axle load divided by the nr. of wheels. Furthermore contact pressures might be excessive because of high tire pressures that have to be used because of overloading. This paper describes the results of a rather extensive axle and wheel load survey that took place in Ghana in the early 1990’s. It will be shown that axle load measurements are not sufficient at all to determine the magnitude of the overloading problem. Wheel load and tire pressure measurements should always be part of surveys into the overloading of trucks. Furthermore it will be shown how material specifications should be increased in order road pavements to be able to sustain excessive loadings.
     André  Molenaar, Delft University of Technology, Netherlands, a.a.a.molenaar@tudelft.nl

Soil Mechanics

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05-0025 - Reliability of Piezocone Penetration Test Methods for Estimating the Coefficient of Consolidation of Cohesive Soils
Session 260
This paper presents the evaluation of the current PCPT interpretation methods for their capability to reasonably estimate the vertical coefficient of consolidation (cv) of cohesive soils utilizing the piezocone dissipation tests. The PCPT methods included in this evaluation are: Teh and Houlsby (1), Levadoux and Baligh (2), Robertson and Campanella (3), Teh (4), Senneset et al. (5) (two methods), and Jones and Rust (6). To achieve this goal, six sites in Louisiana were selected for this study. In each site, in-situ PCPT tests were performed and soundings of cone tip resistance (qc), sleeve friction (fs), and pore pressures at different locations (u1 and u2) were recorded. Piezocone dissipation tests were also conducted at different penetration depths. High quality shelby tube samples were collected close to the PCPT tests and used to carry out a comprehensive laboratory-testing program. The vertical coefficient of consolidation (cv), predicted using the different interpretation methods, were compared with the reference values determined from the oedometer laboratory tests. The results of this research study showed that the Teh and Houlsby (1) and Teh (4) methods can estimate cv better than the other prediction methods.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens

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05-0037 - Application of Dynamic Cone Penetrometer in Pavement Construction Control
Session 260
This paper presents the results of a comprehensive testing program that was conducted to evaluate the potential use of the Dynamic Cone Pentrometer (DCP) device in the quality control/quality assurance (QC/QA) procedure during the construction of pavement layers and embankments. The laboratory tests were conducted on different materials prepared inside two test boxes 1.5m x 0.9m x 0.9m (5ft x 3ft x 3ft) located at Louisiana Transportation Research Center (LTRC). The field tests were conducted on different highway sections in Louisiana. In addition, nine test sections were constructed and tested at the Pavement Research facility (PRF) site of the LTRC. In all laboratory and field tests, DCP tests were conducted in companion with the Plate Load Test (PLT). In addition, Falling Weight Deflectometer (FWD) tests were conducted on the field sections. CBR laboratory tests were also performed on samples collected from the tested sections. Regression analysis was carried out on the collected data to correlate the DCP-PR with the three reference tests used in this study (PLT, FWD and CBR). Further field tests were conducted to verify the developed regression models. The results of these tests indicated that the developed models yielded good predictions of the measured FWD moduli and CBR values. This suggests that these models can be used to reliably evaluate the stiffness/strength of different pavement materials.
     Murad Yusuf Abu-Farsakh, Louisiana State University, cefars@lsu.edu
     Munir D. Nazzal, Ohio University, Athens
     Khalid A. Alshibli, University of Tennessee, Knoxville
     Ekram  Seyman, Louisiana State University

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05-0281 - Simplified Laboratory Assessment of Subgrade Performance Parameters for Mechanistic Design of Pavement Foundations
Session 260
With the increasing agenda for sustainability, the UK is attempting to move away from the empirical design of pavement foundations to develop a performance specification approach to facilitate analytical design. For analytical design the measurement of the subgrade performance parameters of stiffness and resistance to permanent deformation are required. These parameters ideally need to be assessed concurrently under loading and environmental conditions similar to those the materials will experience in the field. To date, measurement of these parameters is largely confined to research laboratories using cyclic triaxial testing with on sample strain measurement. This apparatus is considered too complicated for routine commercial use, hence this potentially limits the implementation of laboratory performance evaluation for pavement foundation design. A previous program of cyclic triaxial testing on clay subgrades indicated a series of useful correlations between strength and permanent deformation behavior (via a threshold stress), and material stiffness at this threshold. This paper reviews the previous work and utilizing these correlations presents data from tests on three different clay materials performed to develop simplified equipment and procedures for the routine measurement of the required design parameters. It is shown that simple monotonic tests can measure a subgrade stiffness for a simplified performance based design. It re-evaluates the previous data (in the light of the recent work) to show a boundary correlation that may allow a shear strength based parameter to control (in design) the onset of permanent deformation, and details how long-term subgrade water content changes can be accommodated.
     Matthew William Frost, Loughborough University, United Kingdom, m.w.frost@lboro.ac.uk
     Paul  Edwards, Scott Wilson Pavement Engineering Ltd., United Kingdom
     Paul Richard Fleming, Loughborough University, United Kingdom
     Stuart John Arnold, Ramboll Whitbybird

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05-0312 - Evaluation of Geophysical Methods for Alaskan Material Sources
Session 365
A geophysical investigation was carried out at four material source sites in Alaska’s interior to evaluate the effectiveness of three geophysical methods for assisting in site characterization. The methods included: ground penetrating radar (GPR), seismic wave refraction, and electrical resistivity imaging (EI). Each of the three methods was used at four potential material sites for which borehole test data was available. One site was located on the Steese Highway and the others were along the Dalton Highway. The objective was to determine which method or methods can best be used to understand the geologic framework of a site under various conditions. Of particular interest was identifying the best geophysical approach, with regards to instrumentation, field procedures, analysis and presentation, for identifying and mapping materials that would be appropriate for transportation construction projects. Results showed that the success of the geophysical methods, in terms of useful results and ease of use, was very dependent on both surface and subsurface conditions of the particular site. The study found that the GPR was the most time- and cost-efficient method, however it provided the least subsurface penetration and quantitative information on the materials. Thus, at sites with thick sand/gravel layers, the GPR did not map the deeper boundaries as clearly as the seismic refraction or EI methods. However, seismic refraction, capable of significant depth of penetration, was ineffective in the presence of surface organic soils. Finally, although EI produced relatively detailed images showing lateral and vertical variations in resistivity, the interpretation of the information was, in some situations, ambiguous and could not always be correlated with the collected borehole data.
     Steve  Saboundjian Ph.D., P.E., Alaska Department of Transportation and Public Facilities, steve.saboundjian@alaska.gov
     Robert G. Dugan CPG, Golder Associates, Inc.
     John  Liu Ph.D., Golder Associates, Inc.

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05-0326 - Axle and Wheel Loads in Developing Countries and Consequences for Material Specifications
AFB30
Overloading of trucks is a serious problem in developing countries. It results in high axle and wheel loads which have a devastating effect on the pavement structure. It is common practice to express the damaging effect in terms of an equivalent number of standard axle loads. The question arises whether this is a useful approach in case of overloaded trucks. The reason for this doubt is because of the fact that due to poor maintenance of the trucks, improper loading etc, wheel loads might occur which are much higher than the axle load divided by the nr. of wheels. Furthermore contact pressures might be excessive because of high tire pressures that have to be used because of overloading. This paper describes the results of a rather extensive axle and wheel load survey that took place in Ghana in the early 1990’s. It will be shown that axle load measurements are not sufficient at all to determine the magnitude of the overloading problem. Wheel load and tire pressure measurements should always be part of surveys into the overloading of trucks. Furthermore it will be shown how material specifications should be increased in order road pavements to be able to sustain excessive loadings.
     André  Molenaar, Delft University of Technology, Netherlands, a.a.a.molenaar@tudelft.nl

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05-0431 - Lateral Load Response of Two Identical Bridge Column-Foundation Systems in Warm and Freezing Conditions
Session 814
Ambient temperatures in the Midwest and East Coast of the United States typically range from 35oC to -20oC. Cold temperatures below freezing significantly increase the soil shear strength and stiffness. Although the effects are not as significant, the strength of concrete and reinforcing steel are also increased by cold temperatures. Consequently, the lateral load behavior of bridge columns becomes dependent on seasonal weather conditions, which is not addressed in the current design practice. This paper summarizes the results of large-scale cyclic lateral load tests on two identical bridge column–cast-in-drilled-hole shaft systems, installed in glacial till soil, and their predicted behavior. The tests were conducted at 23oC and -10oC. When compared to the warm temperature test, the cold temperature test showed more than twice the elastic stiffness and 39% increase in the lateral strength, while shifting the location of the maximum moment upward by 0.74 m. Using the results from Cone Penetration (CPT) and Pressuremeter (PMT) soil tests, lateral load behavior of the test units were predicted using numerical models that consisted of beam elements representing the column and the shaft and lateral nonlinear springs modeling the soil response. The temperature effects on soil, concrete and steel were accounted for when developing the soil response and moment-curvature behavior of the beam elements. The overall response of the bridge column-foundation systems predicted using the p-y curves developed from CPT matched the measured response more closely than that developed using the PMT since PMT measured the average response of the frozen soil layer.
     Muhannad T. Suleiman, Lehigh University, mts210@lehigh.edu
     Sri  Sritharan, Iowa State University
     David J. White, Iowa State University

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05-0797 - Design Methodology for Drilled Shafts Supporting Sound Walls
Session 802
Drilled shafts are widely adopted as the foundation for sound walls. However, there has been a lack of uniformity in design and analysis methods and design criteria, in terms of factor of safety against ultimate capacity failure as well as the allowable deflection. In order to establish a uniform design methodology for the drilled shafts supporting sound walls in cohesive and cohesionless soils, respectively, a database of full-scale lateral load tests on fully instrumented drilled shafts was collected. Based on the compiled database, existing design methods and design criteria of laterally loaded drilled shafts were evaluated. Broms method and COM624P (or LPILE) are suggested as the design methods for drilled shafts supporting sound walls in both cohesive and cohesionless soils. Additionally, the corresponding design criteria, including factor of safety and permissible deflection, for both design methods are recommended. Two full-scale lateral load tests on fully instrumented drilled shafts were subsequently conducted in Colorado for further verify the design recommendation. A comprehensive geotechnical investigation program was also carried out at the two new lateral load test sites that included pressuremeter test, SPT, as well as laboratory triaxial UC tests and direct shear tests on the soil samples taken from the lateral load test sites. The test results obtained at these two load test sites were employed to validate the recommended geotechnical design and geotechnical testing methods for the drilled shafts supporting sound walls.
     Ke  Yang, University of Akron, ky6@uakron.edu
     Samer R. Rabab'ah, Gannett Fleming Inc.
     Jamal Hassan Nusairat, E. L. Robinson Engineering
     Naser Mahmood Abu-Hejleh P.E., Federal Highway Administration

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05-0805 - Use of Microcracking to Reduce Shrinkage Cracking in Cement-Treated Bases
Session 411
Shrinkage cracking occurs in cement-treated bases due to desiccation and cement hydration; eventually these cracks start to reflect through the pavement surfacing. While initially considered cosmetic in nature, these cracks open the pavement to water infiltration and increase the likelihood of accelerated pavement distress. Although numerous options exist for minimizing the amount of reflective cracks that appear, this paper focuses on the performance of controlled test sections utilizing a promising approach termed “microcracking.” The microcracking concept can be defined as the application of several vibratory roller passes to the cement treated base at a short curing stage, typically after one to three days, to create a fine network of thin cracks. In addition to the microcracked test sites, the contractor constructed moist cured, dry cured, and asphalt curing membrane sites for comparison. Researchers used falling weight deflectometer (FWD) tests to control the microcracking process, periodic crack surveys to monitor crack performance, and FWD tests through time to track base moduli. Microcracking proved quite effective at reducing shrinkage cracking problems in the base; applying the procedure with three passes of the roller after two to three days curing resulted in the best performance. Additionally, researchers observed that without microcracking, excessively high cement contents result in problematic cracking in the base even if cured according to good construction practice. Microcracking did not result in pavement damage or diminished in-service modulus; thus, microcracking should be considered a viable and inexpensive option to incorporate shrinkage crack control into construction of cement-treated bases.
     Stephen  Sebesta, Texas A&M Transportation Institute , s-sebesta@tamu.edu

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05-0815 - Vibrating Hammer Compaction Test for Granular Soils and Dense-Graded Aggregates
Session 367
Excessive settlements can occur in granular soils where specified field compaction is based on Standard Proctor (ASTM D 698, AASHTO T 99) maximum dry unit weights. A laboratory test program evaluated alternative test methods for granular soil compaction control and showed that a Vibrating Hammer method (similar to British Standard BS 1377:1975, Test 14) has great promise for laboratory compaction of these soils. A One-Point Vibrating Hammer test on an oven-dried soil sample provides the maximum dry unit weight and water content range for effective field compaction of granular soils with up to 35 percent nonplastic fines or 15 percent plastic fines. The maximum dry unit weight obtained is comparable to that from the Vibrating Table test (ASTM D 4253), and is greater than that from the Standard Proctor test (ASTM D 698, AASHTO T 99). The effects of different test variables on obtainable dry unit weights are also presented in this paper, along with vibrating hammer compaction results for dense graded aggregates. While the One-Point test may not work for some dense graded aggregates, the possibility of a Two-Point Vibrating Hammer test is introduced.
     Adam Buser Prochaska EIT, Purdue University
     Vincent  Drnevich P.E., Ph.D., Purdue University, drnevich@purdue.edu
     Daehyeon  Kim, Chosun University, South Korea
     Kurt  Sommer, Indiana Department of Transportation

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05-0881 - Repairing Railway Spur Roadbed Failure Using Geotextile-Encased Columns
Session 534
When a rail bed failure occurs over soft weak soils the repair options are limited to ground improvement techniques or a deep foundation support system. The geotextile encased column method is a new method of embankment support that minimizes post installation settlement as well as reducing the waiting period after installation and before the application of load. The method was developed in Europe for support of high speed rail systems being constructed over compressible peat deposits. Kleinfelder used the GEC method to repair the failure of a rail spur line located on fill over Bay mud in Oakland California. The method consists of an array of closely spaced rock columns installed through a soft weak soil layer. The rock columns are wrapped in a geotextile sock forming a uniformly shaped column. The columns are installed using a steel pipe casing fitted with a trap door on the bottom. The array of rock columns is covered with a layer of geogrid and 24 inches (61mm) of aggregate base to form the rail bed. A load test was performed to measure settlement. It was concluded that the GEC’s are less costly than other methods such as deep mixing or augercast piles with pedestals, GEC’s can be loaded immediately saving delays for curing or preloading, and GEC’s reduce the post installation settlement compared to stone columns.
     Richard Donovan Short, Kleinfelder, Inc., dshort@kleinfelder.com
     Yogesh  Prashar, Kleinfelder, Inc.

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05-0894 - Improvement of the Geotechnical Axial Design Methodology for Colorado’s Drilled Shafts Socketed in Weak Rocks
Session 802
Drilled shaft foundations embedded in weak rock formations support a large percentage of bridges in Colorado. Since the 1960s, empirical methods have been used for the axial geotechnical design drilled shafts in Colorado that entirely deviate from the AASHTO design methods. The margin of safety and expected shaft settlement are unknown in these empirical methods, however, both are needed for the implementation of the new and more accurate AASHTO Load and Resistance Factor Design (LRFD) method in CDOT (Colorado Dept. of Transportation) design guidelines. Load tests on drilled shafts provide the most accurate design information and research data for improvement of the design methods. In 2002, four Osterberg axial load tests were performed on drilled shafts embedded in the typical range of weak rocks encountered in Denver: soil-like claystone to very hard sandy claystone to even much harder clayey sandstone. To maximize the benefits of this work, the O-Cell load test results and information on the construction and materials of the test shafts were documented, and an extensive program of simple geotechnical tests was performed at the load test sites. This included standard penetration tests (SPT), unconfined compressive strength tests (UCT), and pressuremeter tests (PMT). Analysis of all test data, information, and experience gained in this study were employed to provide: 1) best-fit equations to predict the unconfined strength of weak rocks from SPT, and PMT data, 2) assessment of the CDOT and AASHTO/FHWA design methods; and 3) recommended design equations to predict the shaft ultimate unit base resistance (qmax), side resistance (fmax), and an approximate load-settlement curve as a function of the results of simple geotechnical tests for the weak rock investigated in this study. Other products are developed to help CDOT with implementation of accurate and feasible LRFD methods for the design of drilled shafts.
     Naser Mahmood Abu-Hejleh P.E., Federal Highway Administration, Naser.Abu-Hejleh@fhwa.dot.gov
     Michael Wayne O'Neill (Deceased), No Organization
     Dennis  Hanneman P.E., Geocal, Inc.
     William J. Attwooll P.E., Terracon Consultants

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05-1019 - Pore Pressure Measurement in Blast-Induced Liquefaction Experiments
Session 367
Blast-induced liquefaction experiments have been conducted at a number of test sites to evaluate lateral foundation resistance and soil improvement techniques. Tests can be constructed at full-scale without waiting for an earthquake to occur. In this extreme environment, pore pressure transducers must survive transient blast pressures of 41.4 MPa (6000 psi), yet have enough resolution to measure residual pore pressures of ± 0.69 kPa (0.1 psi). Three different transducer types were evaluated under these demanding conditions and the piezoresistive transducer was clearly found to be the most robust. These sensors were repeatedly subjected to extreme blast pressures and vibration, but still were able to provide accurate time histories of residual pore pressure despite occasional baseline shifts. Although these piezometers are more expensive than the other types, installation techniques were developed which allowed the piezometers to be recovered and reused in subsequent tests to reduce overall costs. These pore pressure sensors make it possible to define the extent of the liquefied zone during blast liquefaction experiment and to understand the soil behavior during cyclic loading of deep foundations.
     Kyle M. Rollins, Brigham Young University, rollinsk@byu.edu
     J. Dusty Lane, Lane Engineering, LLC
     Emily  Dibb, Brigham Young University
     Scott A. Ashford, Oregon State University
     A. Gray Mullins, University of South Florida

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05-1271 - Development of U.S. Army Corps of Engineers Engineering Guidance for the Barge Impact Design of Navigation Structures
Session 254
This paper presents the development of U.S. Army Corps of Engineers (USACE) guidance, Engineering Technical Letter 1110-2-563, for the design of navigation structures subject to barge impact loading. The new guidance was developed around the results from full-scale experiments conducted under the Innovations for Navigation Projects Research and Development Program. An empirical impact force model was derived from the experimental data and probabilistic procedures were developed to assist with the design and analysis of navigation structures for impact loads due to transiting vessels. The uncertainty in loadings due to a wide range of events from both natural and human sources are crucial in design of these critical structures. These uncertainties are defined in terms of the distributions for impact angles, velocities and tow masses as well as the need to account for loss of power and control events. The methods developed in the guidance for the design and analysis of these structures are focused on defining the return periods for the usual, unusual, and extreme loads for the navigation structures. An example of the probabilistic procedures developed in the guidance is highlighted for the design of an upper guide wall at a navigation project.
     Robert C. Patev, U.S. Army Corps of Engineers, Robert.C.Patev@usace.army.mil

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05-1318 - Validation of Enhanced Integrated Climatic Model Predictions with New Jersey Seasonal Monitoring Data
Session 642
Environment is one of the essential factors that influence pavement material behavior and consequently its performance. The variation of climatic patterns from region to region coupled with the variation of site specific conditions across North America make it difficult to develop standard models to account for seasonal variation in material properties for all regions. Therefore, the need to develop regional models becomes an essential requirement for most transportation departments. The Enhanced Integrated Climatic Model (EICM) was used to determine its suitability in predicting subsurface temperature and moisture conditions within New Jersey sites. The validation of the model was carried out using environmental data collected through pavement instrumentation as part of a large-scale research study being undertaken under the sponsorship of the New Jersey Department of Transportation (NJDOT). The validation was carried out using site-specific data as input to the model and compared the model output parameters against field-measured values. This paper reports the results of the validation for two of the instrumented sites. Results of the study do not indicate a high correlation between EICM-predicted temperature and moisture profiles for the various pavement layers as compared to measured values.
     Zubair  Ahmed, Stantec Consulting, zahmed@stantec.com
     Ivana  Marukic, Stantec Consulting
     Sameh  Zaghloul, International Transportation Asset Management Specialists (ITAMSs)
     Nicholas P. Vitillo, Center for Advanced Infrastructure and Transportation (CAIT)

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05-1367 - Development of Seasonal Adjustment Models for Flexible Pavements
Session 642
Pavement design and performance are highly influenced by environmental factors such as temperature and moisture. Since temperature and moisture conditions vary with time (daily, seasonal and longer cycles), adjustment models are required to account for these variations and to bring pavement response parameters measured at different periods to the same standard conditions. A study funded by the New Jersey Department of Transportation (NJDOT) and the Federal Highway Administration (FHWA) is underway to develop temperature and seasonal adjustment models that suit New Jersey conditions. These models will be used in the network- and project-level pavement evaluation, analysis and design. Twenty-four test sections were instrumented to continuously measure environmental and climatic parameters. Deflection testing is being performed on a monthly basis (and bi-monthly during the recovery periods) for the last two years. In addition, two 24-hour testing cycles, in which tests are repeated every 2 hours for a 24-hour period, were performed on selected sections. Comprehensive analyses are performed on the collected data; which include backcalculation to determine the in-situ structural capacity under different environmental conditions, correlation to correlate weather data and sub-surface parameters, and Analysis Of Variance (ANOVA) to study the significance of different environmental parameters on pavements. Regression analysis is then performed to develop models that can be used to predict the impact of environmental factors on pavement performance. Also, statistical and empirical temperature and seasonal correction models are developed. This paper presents the developed models and some of the findings of this study.
     Sameh  Zaghloul, International Transportation Asset Management Specialists (ITAMSs), sameh_zaghloul@hotmail.com
     Amr  Ayed, Stantec Consulting
     Halim Omar Abd El Halim, Carleton University, Canada
     Nicholas P. Vitillo, Center for Advanced Infrastructure and Transportation (CAIT)
     Nenad  Gucunski Ph.D., Rutgers University

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05-1395 - Development of Methodology to Include Structural Contribution of Alternative Working Platforms in Pavement Structure
Session 338
This study was conducted to develop a methodology to incorporate the structural contribution of working platforms, including those constructed with industrial by-products, into the design of flexible pavements. Structural contribution of the working platform was quantified using the 1993 AASHTO flexible pavement design guide in terms of a structural number or an effective roadbed modulus. Resilient modulus obtained from large-scale model experiments conducted on several working platform materials (i.e., breaker run, grade 2 gravel, foundry slag, foundry sand, and bottom ash) were used in the analysis. Design charts are presented that show the structural number or the roadbed modulus as a function of type of material and thickness of the working platform.
     Burak Fevzi Tanyu, George Mason University, btanyu@gmu.edu

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05-1533 - Behavior of Fiber-Reinforced Polymer Composite Under Vertical Loads
Session 802
Fiber Reinforced Polymer (FRP) composite materials represent an alternative construction material for the piling industry, which can be effectively used to address the degradation problems of conventional pile materials, specifically in water front environments and aggressive soils. The engineering use of FRP piles on a widespread basis requires development and evaluation of reliable testing procedures and design methods in order to evaluate the load-settlement curve of these composite piles and their static capacity. In particular, full scale loading tests on FRP piles need to be conducted in order to evaluate the behavior of these types of piles under vertical loads. The main objective of the study described in this paper was to conduct a full-scale experiment, including dynamic and static load tests on FRP piles, in order to address these engineering needs, and assess the feasibility of using FRP composite piles as vertical load bearing piles. This paper presents the experimental results and their engineering analysis.
     Ilan  Juran, Polytechnic University of New York, ijuran@poly.edu
     Uri  Komornik, Polytechnic University of New York

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05-1593 - Comparison of the Bidirectional Load Test with the Top-Down Load Test
Session 814
For the last decade, the Osterberg testing method has been advantageous over the conventional pile load testing method in many aspects. However, because the O-cell test uses a loading mechanism entirely different from that of the conventional pile loading testing method, many investigators and practicing engineers have been concerned that the O-cell test would give inaccurate results, especially about the pile head settlement behavior. Therefore, a bi-directional load test using the Osterberg method and the conventional top-down load test were executed on 1.5 m diameter cast-in-situ concrete piles at the same time and site. Strain gauges were placed on the piles. The two tests gave similar load transfer curves at various depth of piles. However, the top-down equivalent curve constructed from the bi-directional load test results predicted the pile head settlement under the pile design load to be about one half of that predicted by the conventional top-down load test. To improve the prediction accuracy of the top-down equivalent curve, a simple method that accounts for the pile compression is proposed. It was also shown that the strain gauge measurement data from the bi-directional load test could reproduce almost the same top-down curve.
     Oh Sung  Kwon, Daelim Industrial Company, Ltd., South Korea
     Yongkyu  Choi, Kyungsung University, South Korea
     Ohkyun  Kwon, Keimyung University, South Korea
     Myoung Mo  Kim, Seoul National University, South Korea, geotech@snu.ac.kr

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05-1609 - Resilient Modulus Testing on Indiana Subgrade Soils
Session 210
ABSTRACT Resilient modulus has been used for characterizing stress-strain behavior of subgrades in the design of pavements. Recently the Resilient modulus (Mr) testing procedure has been upgraded through AASHTO T 307. Since the testing procedure is still complex, the testing has not been widely implemented in practice. In this study, the applicability of a simplified procedure with a confining pressure of 2 psi and deviator stresses of 2, 4, 6, 8, 10, and 15 psi was investigated on the typical coarse-grained and fine-grained subgrade soils encountered in Indiana. The results obtained from the simplified procedure are comparable with those obtained from AASHTO T 307 which calls for 15 combinations of stresses. This shows the simplified procedure to be feasible and effective for design purpose. For soils exhibiting excessive permanent deformation, use of deformed length is desirable for more accurate calculation of Mr. Usually the soils compacted dry of optimum shows the largest Mr for coarse-grained soils due to capillary suction, but it not necessary true for fine-grained soils. A predictive model to estimate regression coefficients k1, k2, and k3 using 11 soil variables obtained from the soil property tests and the Standard Proctor tests was developed. The predicted regression coefficient compares well with measured ones.
     Daehyeon  Kim, Chosun University, South Korea, dkimgeo@gmail.com
     Nayyar Zia Siddiki, Indiana Department of Transportation

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05-1779 - Thaw Weakening Mitigation of Unpaved Roads in Vermont
Session 642
We evaluated the performance of several techniques thought to mitigate deterioration of unpaved roads during spring thaw. Each potential remedy was aimed at providing some combination of limiting the availability of moisture in the winter, improving drainage during spring and strengthening the upper portion of the road. With one exception, each technique implemented uses locally and/or commercially available materials and all were easy to construct, i.e., a town road crew could build it. Construction was followed by two seasons of monitoring. We compared the percentage of the road covered in ruts and strength estimates based on dynamic cone penetrometer values for treated and control sections. Methods that either 1) permanently improved the strength of the top 12 inches of the road or 2) decreased the water content of the upper 12 inches of the road resulted in significant performance improvement during spring thaw.
     Karen S. Henry PhD, United States Air Force Academy, Karen.Henry@usafa.edu
     James P. Olson, University of Vermont
     Stephen P. Farrington, Transcendev
     Christopher C Benda, Vermont Agency of Transportation
     John  Lens, GeoDesign Inc.

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05-1880 - Evolution of Pavement Winter Roughness
Session 603
The functional service level of roads is quantified in terms of roughness. This parameter considers every road surface defect causing passenger vehicle discomfort. Roughness is measured using a quality index, the IRI (International Roughness Index). Roughness gives an overall appreciation of road profile quality without, however, permitting a deeper analysis. In fact, the overall value of the IRI does not discriminate between the two main factors responsible for winter deterioration of roughness, the first being the subgrade differential heave and the second being heave cracks. Differential heave is obtained from the variability in frost susceptibility of subgrade. This phenomenon, which occurs deep in the subgrade, is detectable by isolating the long wave lengths produced at the road surface from the longitudinal profile. Heave cracks are a superficial phenomenon greatly influenced by the application of de-icing salts. By isolating the short wave lengths from the profile, it is possible to highlight the influence of this phenomenon on deterioration. The goal of this research is therefore to establish, using a filtering technique of road profile, the contribution of these two main factors to winter deterioration of roughness on five road sections in the Québec City area. This study will then allow the development of a tool to determine the dominant factor for deterioration and therefore the use of the best technique to rehabilitate roads.
     Nicolas  Fradette, No Organization
     Pascale  Pierre, Laval University, Canada, ppierre@gci.ulaval.ca
     Guy  Doré, Universite Laval, Canada
     Serge  Hébert, Laval University, Canada

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05-1892 - Soil Stabilization and Modification Using Fresh and Landfill Cement Kiln Dust
Session 537
A laboratory study was undertaken to evaluate the performance of two fresh and one landfilled cement kiln dust (CKD) for soil stabilization. The experimental program made use of three CL clays and included compaction, unconfined compression, swell, CBR tests as well as limits and pH measurements on the soil-CKD mixtures. Despite the strong similarity in composition and particle size the three CKDs performed very differently. Only one fresh CKD was found to be sufficiently reactive (thanks to presence of free lime), and showed potential to be used for soil stabilization at addition levels of 15% or greater. The treatment effectiveness was observed to be markedly soil dependent, and significant improvement in strength was observed only when the CKD addition was associated with small changes in the moisture-density relationship. The results for the other fresh and the landfilled CKD suggest that these materials may be used for treating wet subgrades or water logged areas. In presence of 10-20% of these CKDs it became possible to compact soils at water contents outside their compaction range, and the further addition of 1% Portland cement produced mixtures of considerable strength. The results obtained highlight the importance of knowing the plant operation history and chemical composition (specifically free lime) of each batch of CKD collected; they demonstrate that the loss on ignition is not a good indicator of the reactivity of a CKD; and suggest that the change in plastic limit and possibly in pH may give insight into the potential of a particular CKD for soil stabilization.
     Asha  Shreekrishnavilasam, Purdue University
     Sunie  Rahardja, R.W. Armstrong
     Robert  Kmetz, Purdue University
     Marika  Santagata, Purdue University, mks@purdue.edu

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05-2038 - Study of Problematic Silt Stabilization
Session 483
Soils with high silt content are a common occurrence and can raise widespread road construction and performance problems due to their low strength, minimal bearing capacity and highly moisture susceptibility. Their stability is greatly influenced by the degree of densification achieved during compaction. Problematic silts subjected to high compaction energies develop pumping phenomenon, especially when the soil is wet of optimum. The strength and stiffness of silty-subgrade soils is also greatly reduced when moisture infiltrates the compacted soil due to capillary action during post construction period. Moisture susceptibility is an important factor that affects the mechanical properties of subgrade materials. This paper presents a study regarding the identification and stabilization of problematic silts. The characteristics of a set of three soils with a high potential to pump are investigated. Conditions generating pumping phenomenon are duplicated in the laboratory by a set of cyclic triaxial tests. In addition to the high silt content, the plasticity character and moisture susceptibility are noted as significant factors for pumping. The potential for the stabilization of problematic silts with Portland cement and lime is also studied. The percentages of additives are considered based on strength criteria and the evolution of moisture susceptibility of the subgrade material is investigated using Tube Suction Test. The results demonstrate Portland cement represents the most effective chemical additive for the soils considered in this study. This paper demonstrates the relevance of moisture susceptibility criteria as an important consideration in the design specifications for subgrade stabilization.
     Bogdan George Barbu, Texas A&M Transportation Institute , b-barbu@tamu.edu
     Kenneth  McManis, University of New Orleans

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05-2239 - Ettringite Formation in Lime-Treated Soils: Establishing Thermodynamic Foundations for Engineering Practice
Session 537
The use of calcium-based stabilizers such as calcium oxide (lime) in sulfate-bearing clay soils has historically lead to distress due to the formation of a mineral called ettringite and possibly thaumasite. In trying to control the damage associated with such occurrences, engineers have attempted to determine a threshold value of soluble sulfates, a quantity that is relatively easy and quick to measure, at which significant ettringite growth and, therefore, structural distress occurs. This is indeed a complex problem related not only to soil composition but also construction methods, availability of water, ion migration, and whether the expansive mineral growth can be accommodated by void structure. Unfortunately, experience alone and “rules-of-thumb” based on experience is not sufficient to deal with this complex issue. This paper describes how thermodynamic geochemical models of the lime treated soil can be used as a first step toward establishing problematic threshold levels of soluble sulfates for a specific soil. A foundation for the model development is presented, and two different soils are compared to illustrate their very different sensitivities to ettringite growth upon the addition of hydrated lime. Since the model predicts ettringite growth based upon site-specific properties, the paper also shows how the model can be used to assess the potential amelioration effects of soluble silica.
     Dallas N. Little, Texas A&M Transportation Institute , d-little@tamu.edu
     Bruce E. Herbert, Texas A&M University
     Sachin  Kunagalli Natarajan, Texas A&M University System

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05-2524 - Early-Age Strength Assessment of Cement-Treated Base Material
Session 411
In order to avoid early-age damage to cement-treated base (CTB) materials, the cement must be allowed to cure for a period of time before the pavement can be opened to traffic. The purpose of this research was to evaluate the utility of the soil stiffness gauge (SSG), heavy Clegg impact soil tester (CIST), dynamic cone penetrometer, and falling-weight deflectometer for assessing early-age strength gain of cement-stabilized materials. Experimentation was performed at four sites on a pavement reconstruction project along Interstate 84 in Morgan, Utah, in which cement stabilization was used in conjunction with full-depth recycling. Each site was stationed to facilitate repeated measurements at the same locations with different devices and at different curing times. Because of the considerable attention they have received in the pavement construction industry for routine quality control and quality assurance programs, the SSG and CIST were the primary focus of the research. Statistical techniques were utilized to evaluate the repeatability of these devices and their sensitivity to curing time. The results indicated that while the SSG was more repeatable at one site, the CIST data were markedly more sensitive to curing time than the SSG data at all of the cement-treated sites during the first 72 hours after construction. For this reason, the data suggest that the CIST offers greater overall utility than the SSG for monitoring early-age strength gain of CTB. Further research is needed to investigate appropriate thresholds and protocols for these testing methods that ensure adequate reliability of the collected data.
     W. Spencer Guthrie, Brigham Young University, guthrie@byu.edu
     Tyler B. Young, Brigham Young University
     Brandon James Blankenagel, City of Spokane
     Dane A. Cooley, Kimley-Horn & Associates, Inc.

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05-2690 - Can Spring Load Restrictions on Low-Volume Roads Be Shortened Without Increasing Road Damage?
Session 484
Major highways are designed to withstand heavy vehicles and high volumes of traffic year round. However, low volume roads in seasonal frost areas are highly susceptible to damage from trafficking by heavy vehicles during spring thaw. Conventional practice is to place partial or full spring load restrictions on low volume roads during spring thaw. This practice will reduce damage significantly. However, companies whose livelihood depends on trucking can suffer major economic losses as they await removal of load restrictions. Using reduced tire pressure constitutes a less conventional road usage technique that can also contribute toward reducing springtime damage. Reducing tire pressure generally appears to be less effective than reducing load. Nevertheless, it does appear that the load restriction window can be reduced in duration by implementing a reduction in tire pressure for a short duration starting toward the latter part of the standard spring load restriction. Using a mechanistic pavement design and evaluation model for seasonal frost areas that had been under development by the US Army Corps of Engineers, this paper discusses the development of a critical combination of load and tire pressure reduction that contributes toward optimizing the balance between minimizing springtime road damage and minimizing disruption to local economies caused by load restrictions.
     Maureen A. Kestler, USDA Forest Service, mkestler@fs.fed.us
     Richard L. Berg, FROST Associates
     John E. Haddock, Purdue University

Structures

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05-0242 - Precast Bridge Deck Solutions for Rapid Rehabilitation of Truss Bridge
Session 706
ABSTRACT The Bridge and Structures Office completed the design for the Lewis and Clark Bridge deck replacement project in October of 2002. This historic bridge, designed by Joseph B. Strauss of Golden Gate Bridge fame, was built in 1930. It spans the Columbia River between Longview, Washington and Rainier, Oregon. The bridge consists of a 2,720-foot (829m) main through-truss section, a 927-foot (283m) deck truss section on the Oregon side, and a 168-foot (51m) deck truss and a 1,507 foot (459m) 12 span rolled-beam section on the Washington side. The bridge could only be closed to traffic at night from 9:30 P.M. to 5:30 A.M. during construction due to traffic constraints. Night closures were limited to 120 days and single-lane closures were limited to 200 days. The WSDOT Bridge Office designed a method to replace the existing concrete deck on the main through-truss and deck trusses, and for widening the existing deck on the rolled beam spans, using precast concrete deck panels. A total of 103 precast panels with a constant width of 36 feet (11.97m) and variable lengths of 25 to 45 feet (7.62 to 13.72m) were placed on the trusses. For the rolled-beam spans 46 precast panels with a constant width of 4 feet (1.22m) and variable lengths of 58 to 70 feet (17.68 to 21.34m) were placed. Construction is complete as of this date. This paper will examine in depth the design, construction and lifting operations involved with the replacement of the existing bridge deck with precast full width panels. The total cost of this project was $27 million.
     Munindra  Talukdar, Washington State Department of Transportation, talukdm@wsdot.wa.gov

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05-0326 - Axle and Wheel Loads in Developing Countries and Consequences for Material Specifications
AFB30
Overloading of trucks is a serious problem in developing countries. It results in high axle and wheel loads which have a devastating effect on the pavement structure. It is common practice to express the damaging effect in terms of an equivalent number of standard axle loads. The question arises whether this is a useful approach in case of overloaded trucks. The reason for this doubt is because of the fact that due to poor maintenance of the trucks, improper loading etc, wheel loads might occur which are much higher than the axle load divided by the nr. of wheels. Furthermore contact pressures might be excessive because of high tire pressures that have to be used because of overloading. This paper describes the results of a rather extensive axle and wheel load survey that took place in Ghana in the early 1990’s. It will be shown that axle load measurements are not sufficient at all to determine the magnitude of the overloading problem. Wheel load and tire pressure measurements should always be part of surveys into the overloading of trucks. Furthermore it will be shown how material specifications should be increased in order road pavements to be able to sustain excessive loadings.
     André  Molenaar, Delft University of Technology, Netherlands, a.a.a.molenaar@tudelft.nl

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05-0431 - Lateral Load Response of Two Identical Bridge Column-Foundation Systems in Warm and Freezing Conditions
Session 814
Ambient temperatures in the Midwest and East Coast of the United States typically range from 35oC to -20oC. Cold temperatures below freezing significantly increase the soil shear strength and stiffness. Although the effects are not as significant, the strength of concrete and reinforcing steel are also increased by cold temperatures. Consequently, the lateral load behavior of bridge columns becomes dependent on seasonal weather conditions, which is not addressed in the current design practice. This paper summarizes the results of large-scale cyclic lateral load tests on two identical bridge column–cast-in-drilled-hole shaft systems, installed in glacial till soil, and their predicted behavior. The tests were conducted at 23oC and -10oC. When compared to the warm temperature test, the cold temperature test showed more than twice the elastic stiffness and 39% increase in the lateral strength, while shifting the location of the maximum moment upward by 0.74 m. Using the results from Cone Penetration (CPT) and Pressuremeter (PMT) soil tests, lateral load behavior of the test units were predicted using numerical models that consisted of beam elements representing the column and the shaft and lateral nonlinear springs modeling the soil response. The temperature effects on soil, concrete and steel were accounted for when developing the soil response and moment-curvature behavior of the beam elements. The overall response of the bridge column-foundation systems predicted using the p-y curves developed from CPT matched the measured response more closely than that developed using the PMT since PMT measured the average response of the frozen soil layer.
     Muhannad T. Suleiman, Lehigh University, mts210@lehigh.edu
     Sri  Sritharan, Iowa State University
     David J. White, Iowa State University

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05-0727 - Design and Construction of a Full-Width, Full-Depth Precast Concrete Deck Slab on Steel Girder Bridge
Session 706
The existing West Sandusky Bridge over I-75, located in Findlay, Ohio, is being replaced with a new 170’ span hybrid steel plate girder bridge with concrete deck. In order to minimize closure times on West Sandusky Street, and reduce traffic delays on I-75 during construction, full-width, full-depth precast concrete deck panels will be used for the construction of the bridge deck. During preliminary design, a variety of alternate precast deck slab designs were considered, and a full-width, full-depth precast deck slab was selected as the preferred alternative. The precast deck panels are post-tensioned both longitudinally and transversely to minimize cracking and improve durability. The deck panels are constructed with shear stud pockets to allow for the installation of shear studs after erection and post-tensioning. During detail design, a finite element analysis of the bridge deck was carried out to determine the required level of prestressing in the deck. A time dependent analysis was subsequently carried out to determine the long term creep effects and post-tensioning losses, including the effects of restraint from the steel girders. A sensitivity analysis was carried out to determine the optimum curing time required prior to stressing the longitudinal post-tensioning tendons and grouting the shear pockets. The steel plate girders were designed for the additional long term creep effects due to the post-tensioning of the deck, which imposed additional axial loads and moments on the steel girders.
     Alex Thomas Harrison, CH2M Hill, aharris1@ch2m.com
     Norman David LeBlanc, Totten Sims Hubicki Associates

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05-0797 - Design Methodology for Drilled Shafts Supporting Sound Walls
Session 802
Drilled shafts are widely adopted as the foundation for sound walls. However, there has been a lack of uniformity in design and analysis methods and design criteria, in terms of factor of safety against ultimate capacity failure as well as the allowable deflection. In order to establish a uniform design methodology for the drilled shafts supporting sound walls in cohesive and cohesionless soils, respectively, a database of full-scale lateral load tests on fully instrumented drilled shafts was collected. Based on the compiled database, existing design methods and design criteria of laterally loaded drilled shafts were evaluated. Broms method and COM624P (or LPILE) are suggested as the design methods for drilled shafts supporting sound walls in both cohesive and cohesionless soils. Additionally, the corresponding design criteria, including factor of safety and permissible deflection, for both design methods are recommended. Two full-scale lateral load tests on fully instrumented drilled shafts were subsequently conducted in Colorado for further verify the design recommendation. A comprehensive geotechnical investigation program was also carried out at the two new lateral load test sites that included pressuremeter test, SPT, as well as laboratory triaxial UC tests and direct shear tests on the soil samples taken from the lateral load test sites. The test results obtained at these two load test sites were employed to validate the recommended geotechnical design and geotechnical testing methods for the drilled shafts supporting sound walls.
     Ke  Yang, University of Akron, ky6@uakron.edu
     Samer R. Rabab'ah, Gannett Fleming Inc.
     Jamal Hassan Nusairat, E. L. Robinson Engineering
     Naser Mahmood Abu-Hejleh P.E., Federal Highway Administration

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05-0881 - Repairing Railway Spur Roadbed Failure Using Geotextile-Encased Columns
Session 534
When a rail bed failure occurs over soft weak soils the repair options are limited to ground improvement techniques or a deep foundation support system. The geotextile encased column method is a new method of embankment support that minimizes post installation settlement as well as reducing the waiting period after installation and before the application of load. The method was developed in Europe for support of high speed rail systems being constructed over compressible peat deposits. Kleinfelder used the GEC method to repair the failure of a rail spur line located on fill over Bay mud in Oakland California. The method consists of an array of closely spaced rock columns installed through a soft weak soil layer. The rock columns are wrapped in a geotextile sock forming a uniformly shaped column. The columns are installed using a steel pipe casing fitted with a trap door on the bottom. The array of rock columns is covered with a layer of geogrid and 24 inches (61mm) of aggregate base to form the rail bed. A load test was performed to measure settlement. It was concluded that the GEC’s are less costly than other methods such as deep mixing or augercast piles with pedestals, GEC’s can be loaded immediately saving delays for curing or preloading, and GEC’s reduce the post installation settlement compared to stone columns.
     Richard Donovan Short, Kleinfelder, Inc., dshort@kleinfelder.com
     Yogesh  Prashar, Kleinfelder, Inc.

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05-0887 - Strain Monitoring of Bridges During Paving Operations
Session 727
The Connecticut Department of Transportation, Division of Research, and the University of Connecticut Department of Civil and Environmental Engineering are working together in a Federal Highway Administration Research Project to implement long-term monitoring systems on a network of bridges in the State of Connecticut. Expertise and equipment purchased for these studies has also been utilized to perform short-term studies for the Department to assist in their management of their bridge infrastructure. One of these studies has involved strain monitoring of highway bridges during the passage of extremely heavy loads that occur during paving operations with new equipment. There has been concern that the equipment has the potential to over stress some bridges on interstate highways. As a result, short-term monitoring has been used to determine the live load stresses in bridges during the paving operations using a Material Transfer Vehicle (MTV). The field studies have demonstrated that the bridges monitored during the study were not compromised during the paving operations.
     Eric G. Feldblum, Connecticut Department of Transportation, eric.feldblum@po.state.ct.us
     Paul F. D'Attilio, Connecticut Department of Transportation
     John T. DeWolf, University of Connecticut

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05-0894 - Improvement of the Geotechnical Axial Design Methodology for Colorado’s Drilled Shafts Socketed in Weak Rocks
Session 802
Drilled shaft foundations embedded in weak rock formations support a large percentage of bridges in Colorado. Since the 1960s, empirical methods have been used for the axial geotechnical design drilled shafts in Colorado that entirely deviate from the AASHTO design methods. The margin of safety and expected shaft settlement are unknown in these empirical methods, however, both are needed for the implementation of the new and more accurate AASHTO Load and Resistance Factor Design (LRFD) method in CDOT (Colorado Dept. of Transportation) design guidelines. Load tests on drilled shafts provide the most accurate design information and research data for improvement of the design methods. In 2002, four Osterberg axial load tests were performed on drilled shafts embedded in the typical range of weak rocks encountered in Denver: soil-like claystone to very hard sandy claystone to even much harder clayey sandstone. To maximize the benefits of this work, the O-Cell load test results and information on the construction and materials of the test shafts were documented, and an extensive program of simple geotechnical tests was performed at the load test sites. This included standard penetration tests (SPT), unconfined compressive strength tests (UCT), and pressuremeter tests (PMT). Analysis of all test data, information, and experience gained in this study were employed to provide: 1) best-fit equations to predict the unconfined strength of weak rocks from SPT, and PMT data, 2) assessment of the CDOT and AASHTO/FHWA design methods; and 3) recommended design equations to predict the shaft ultimate unit base resistance (qmax), side resistance (fmax), and an approximate load-settlement curve as a function of the results of simple geotechnical tests for the weak rock investigated in this study. Other products are developed to help CDOT with implementation of accurate and feasible LRFD methods for the design of drilled shafts.
     Naser Mahmood Abu-Hejleh P.E., Federal Highway Administration, Naser.Abu-Hejleh@fhwa.dot.gov
     Michael Wayne O'Neill (Deceased), No Organization
     Dennis  Hanneman P.E., Geocal, Inc.
     William J. Attwooll P.E., Terracon Consultants

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05-1186 - Experimental Investigations of the Effects of Multiple Heat Straightening Repair on the Structural Properties of Bridge Steels
Session 479
Experimental investigations were conducted to evaluate the effects of multiple damage-heat straightening repair cycles, i.e., multiple cycles of damage followed by heat straightening repair on the fundamental structural properties of typical bridge steels ASTM A36, A588, and A7. The damage and repair parameters considered in the study are the damage strain , the restraining stress , and number of multiple damage-repair cycles (Nr). The effects of these parameters are evaluated on the following structural properties: (a) elastic modulus, (b) yield stress, (c) ultimate stress, (d) percent elongation, (e) surface hardness, and (e) fracture toughness. A total of seventy-five laboratory-scale specimens made from A36, A588, or A7 steel were subjected to multiple damage-repair cycles, and their effects on the structural properties were evaluated. The results from the experimental investigations indicate that multiple damage-repair cycles have a small influence (± 15%) on the elastic modulus, yield stress, and ultimate stress. However, the percent elongation and fracture toughness of the damaged-repaired steel are influenced significantly. Based on reductions in the percent elongation and fracture toughness, it is recommended that A7 and A36 steel be limited to three damage-heat straightening repair cycles. A588 steel can be subjected up to five damage-heat straightening repair cycles.
     Keith Joseph Kowalkowski Ph.D, Ruby and Associates, P.C., kowalkowski@rubyusa.com
     Amit Hariom Varma, Purdue University

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05-1271 - Development of U.S. Army Corps of Engineers Engineering Guidance for the Barge Impact Design of Navigation Structures
Session 254
This paper presents the development of U.S. Army Corps of Engineers (USACE) guidance, Engineering Technical Letter 1110-2-563, for the design of navigation structures subject to barge impact loading. The new guidance was developed around the results from full-scale experiments conducted under the Innovations for Navigation Projects Research and Development Program. An empirical impact force model was derived from the experimental data and probabilistic procedures were developed to assist with the design and analysis of navigation structures for impact loads due to transiting vessels. The uncertainty in loadings due to a wide range of events from both natural and human sources are crucial in design of these critical structures. These uncertainties are defined in terms of the distributions for impact angles, velocities and tow masses as well as the need to account for loss of power and control events. The methods developed in the guidance for the design and analysis of these structures are focused on defining the return periods for the usual, unusual, and extreme loads for the navigation structures. An example of the probabilistic procedures developed in the guidance is highlighted for the design of an upper guide wall at a navigation project.
     Robert C. Patev, U.S. Army Corps of Engineers, Robert.C.Patev@usace.army.mil

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05-1533 - Behavior of Fiber-Reinforced Polymer Composite Under Vertical Loads
Session 802
Fiber Reinforced Polymer (FRP) composite materials represent an alternative construction material for the piling industry, which can be effectively used to address the degradation problems of conventional pile materials, specifically in water front environments and aggressive soils. The engineering use of FRP piles on a widespread basis requires development and evaluation of reliable testing procedures and design methods in order to evaluate the load-settlement curve of these composite piles and their static capacity. In particular, full scale loading tests on FRP piles need to be conducted in order to evaluate the behavior of these types of piles under vertical loads. The main objective of the study described in this paper was to conduct a full-scale experiment, including dynamic and static load tests on FRP piles, in order to address these engineering needs, and assess the feasibility of using FRP composite piles as vertical load bearing piles. This paper presents the experimental results and their engineering analysis.
     Ilan  Juran, Polytechnic University of New York, ijuran@poly.edu
     Uri  Komornik, Polytechnic University of New York

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05-1593 - Comparison of the Bidirectional Load Test with the Top-Down Load Test
Session 814
For the last decade, the Osterberg testing method has been advantageous over the conventional pile load testing method in many aspects. However, because the O-cell test uses a loading mechanism entirely different from that of the conventional pile loading testing method, many investigators and practicing engineers have been concerned that the O-cell test would give inaccurate results, especially about the pile head settlement behavior. Therefore, a bi-directional load test using the Osterberg method and the conventional top-down load test were executed on 1.5 m diameter cast-in-situ concrete piles at the same time and site. Strain gauges were placed on the piles. The two tests gave similar load transfer curves at various depth of piles. However, the top-down equivalent curve constructed from the bi-directional load test results predicted the pile head settlement under the pile design load to be about one half of that predicted by the conventional top-down load test. To improve the prediction accuracy of the top-down equivalent curve, a simple method that accounts for the pile compression is proposed. It was also shown that the strain gauge measurement data from the bi-directional load test could reproduce almost the same top-down curve.
     Oh Sung  Kwon, Daelim Industrial Company, Ltd., South Korea
     Yongkyu  Choi, Kyungsung University, South Korea
     Ohkyun  Kwon, Keimyung University, South Korea
     Myoung Mo  Kim, Seoul National University, South Korea, geotech@snu.ac.kr

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05-1741 - Approach to Developing Guidance Notes on Nondestructive Testing of Highway Bridges in United Kingdom
Session 804
The USA has led the international community in developing standards for the NDE of concrete. In order to meet the perceived specific need for a structured approach to the NDT of bridges in the UK, The Highways Agency (HA) has published Advice Notes on the Non-Destructive Testing of Highway Structures. This paper describes the background to these Advice Notes, how they were developed and trialled, what their objectives are, and how they will be extended in the future. The contents are based on research work on various NDT techniques carried out at the University of Edinburgh. The resulting reports have been worked up by the Highways Agency’s NDT Steering Committee into Advice Notes to enable these techniques to be used in practice for the investigation of Highway Structures. The Advice Notes are formed of three tiers; the first tier consisting of General Guidance on NDT; the second tier comprising Areas of Application; and the third tier covering NDT Techniques. This three tier format enables the Advice Notes to be readily extended in the future to cover further areas of application and other NDT techniques.
     Michael Christopher Forde, University of Edinburgh, United Kingdom, m.forde@ed.ac.uk
     Brian  Hill, Highways Agency, United Kingdom
     Iain L. Kennedy-Reid, Atkins Consulting, United Kingdom
     Richard J Woodward, TRL Limited, United Kingdom

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05-2177 - Dynamic Field Performance of Glued Laminated Timber Bridges
Session 727
To better utilize and develop timber structures in transportation, the United States government implemented several national programs starting in the early 1990’s to address the needs of the timber industry. One need was to investigate the dynamic field performance of timber bridges due to vehicular loading. The American Association of State Highway and Transportation Officials (AASHTO) recommend a dynamic load allowance (DLA) of 0.165 for timber bridges. To investigate this codified value, research was needed to determine the dynamic characteristics of timber bridges and to study their dynamic performance. To fulfill this research need, five glued-laminated girder bridges and four longitudinal glued-laminated panel bridges were selected for testing. The testing involved loading the nine structures to obtain dynamic deflection, acceleration, and overall condition state of the bridges. In general, the nine bridges tested were found to have fundamental frequencies between 5 Hz and 11Hz as well as a dynamic load allowance less than 0.25. The bridges found to have dynamic amplifications above specified code values were also found to have physical characteristics (i.e., rough entrances) that likely caused the higher dynamic amplification values.
     Brent Matthew Phares, Iowa State University, bphares@iastate.edu
     Jake  Bigelow, Iowa State University
     Terry J. Wipf, Iowa State University
     Mike  Ritter, USDA Forest Service
     Douglas L. Wood, Institute for Transportation at Iowa State University

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05-2464 - Behavior Evaluation of Existing Plate Girder Bridge Strengthened with External Prestressing Tendons
Session 816
In this study the effect of strengthening on in-service plate girder bridge by means of external prestressing tendons was investigated. The loss of prestressing force with time was investigated while the existing prestressing force was released/re-prestressed. Also a field load test was performed using a live-truck load to evaluate the behavior of the bridge before and after the strengthening. An additional numerical model using FEM was developed and used in the analysis. From the experiments, it was found that the long term loss of prestressing force on the external tendons was negligible and that the strengthening did not significantly affect the dynamic responses of the bridge. However, the strengthening reduced the mid-span deflection by 10-24% and also improved the fatigue resistance and the torsional rigidity of the bridge. The torsional rigidity enhancement arising from the strengthening became more apparent as the truck speed increased. The natural frequencies from the field load test, FEM analysis and suggested formula showed good agreement. It was also found from the dynamic load test that the strengthening did not significantly influence the natural frequency and impact factor.
     Cheolwoo  Park, Kangwon National University, South Korea, tigerpark@kangwon.ac.kr
     Jongsung  Sim, Hanyang University, South Korea
     Young Hoon  Park, Bucheon College

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05-2793 - Method for Automated Discontinuity Analysis of Rock Slopes with Three-Dimensional Laser Scanning
Session 632
This paper describes the interim results of a study to characterize discontinuous rock masses using 3D laser scanning data. One of the main advantages of this method is that now an unbiased, rapid and accurate discontinuity analysis can be done. With 3D laser scanning it is now also possible to measure rock faces whose access is restricted or rock slopes along highways or railway lines where working conditions are hazardous. It is also shown that the proposed method will also be cheaper than traditional manual survey and analysis methods. Laser scanning is a relative new surveying technique, which yields a so-called ‘point cloud’ set of data, where every single point represents a point in 3D space of the scanned rock surface. Since the density of the point cloud can be high (in the order of 5 mm to 1 cm), it allows for an accurate re-construction of the original rock surface in the form of a 3D interpolated and meshed surface, using different interpolation techniques. Through geometric analysis of this 3D mesh and plotting of the facet orientations in a polar plot, it is possible to observe clusters, which represent different rock mass discontinuity sets. With fuzzy k-means clustering algorithms individual discontinuity sets can be outlined automatically and the mean orientations of these identified sets can be computed. Assuming a Fisher’s distribution it is subsequently demonstrated that the facet outliers can be removed. Finally, it is shown that discontinuity set spacings can be calculated as well.
     Siefko  Slob, International Institute for Geo-Information Science and Earth Observation, Netherlands, slob@itc.nl
     Bart  Van Knapen, Delft University of Technology, Netherlands
     Robert  Hack, International Institute for Geo-Information Science and Earth Observation, Netherlands
     Alan Keith Turner, Colorado School of Mines
     John  Kemeny, University of Arizona

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05-2794 - Live Load Deflection Performance of Glued Laminated Timber Girder Bridges
Session 727
To demonstrate and possibly promote the increased use of timber bridges in our nations transportation systems, various agencies have supported research, including the United States Department of Agriculture (USDA)/Forest Products Laboratory and the Federal Highway Administration (FHWA), to develop improved glued-laminated timber bridges. This project is part of this research and is directed towards identifying acceptable live load deflection characteristics of timber bridges. The relationship between live load deflection and the condition of the asphalt wearing surface is of particular interest. To accomplish this, eight glued-laminated timber girder bridges were selected for testing. The performance of the bridges was investigated under live load tests and through bridge inspections. The structures were load tested with fully loaded tandem axle dump trucks and global and differential deflection data were collected. Field tests revealed that a significant amount of the asphalt wearing surface deterioration is the result of differential deck panel deflection.
     Travis Kent Hosteng, Iowa State University, kickhos@iastate.edu
     Brent Matthew Phares, Iowa State University
     Terry J. Wipf, Iowa State University
     Mike  Ritter, USDA Forest Service
     Douglas L. Wood, Institute for Transportation at Iowa State University