2010 Catalog of Practice-Ready Papers

SUBJECT AREAS

  • AICP Certification Maintenance Session
  • Aviation
  • Bituminous Materials
  • Concrete Materials
  • Construction
  • Data and Information Systems
  • Design
  • Freight Systems
  • Geology and Earth Materials
  • Infrastructure Preservation
  • Investing in Our Transportation Future – BOLD Ideas to Meet BIG Challenges
  • Maintenance
  • Management and Leadership
  • Operations
  • Pavement Management
  • Pedestrians and Cycles
  • Public Transportation and Ferries
  • Research and Education
  • Safety
  • Soil Mechanics
  • Structures
  • Users

    INDEX

    AICP Certification Maintenance Session

    10-3437 Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey
    10-4064 New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center

    Aviation

    10-0559 Network Competition and Effects of Open Skies in Transatlantic Aviation
    10-1357 Regional Cooperation, Coordination, and Communication Between Airports During Disasters

    Bituminous Materials

    10-0434 Influence of Reclaimed Asphalt Pavement on Surface Friction
    10-0710 Local Calibration of Mechanistic-Empirical Pavement Design Guide Rutting Model for Minnesota Road Research Project Test Sections
    10-0985 Trackless Tack Coat Materials: Laboratory Evaluation for Performance Acceptance
    10-1050 Bond Expectations for Asphalt Concrete Layers Applied to Milled Surfaces in Virginia
    10-1168 Implementation of Stabilized Blended Calcium Sulfate Materials in Flexible Pavement Design and Construction
    10-1527 Can More Reclaimed Asphalt Pavement Be Added? A Study of Extracted Binder Properties from Plant-Produced Mixtures with up to 25% Reclaimed Asphalt Pavement
    10-1755 Mechanistic Laboratory Evaluation and Field Construction of Recycled Concrete Materials for Use in Road Substructures
    10-2170 Bulk Specific Gravity of Reclaimed Asphalt Pavement Aggregate: Evaluating the Effect on Voids in Mineral Aggregate
    10-3825 Variability in Resilient Modulus of Reclaimed Asphalt Pavement as Base Layer and Its Impact on Flexible Pavement Performance

    Concrete Materials

    10-1042 Scaling Resistance of Concrete Containing Slag Cement: Critical Review
    10-1630 Evaluation of Probing Versus Coring for Determination of Portland Cement Concrete Pavement Thickness
    10-1631 New AASHTO T336-09 Coefficient of Thermal Expansion Test Method: How Will It Affect You?
    10-1704 CRCP Forensic Investigations and Remedial Actions in Virginia
    10-2374 Development of End-Result Specifications for Concrete in Virginia
    10-2943 Alkali-Silica Reactivity Prevention in U.S. Department of Defense

    Construction

    10-0985 Trackless Tack Coat Materials: Laboratory Evaluation for Performance Acceptance
    10-1050 Bond Expectations for Asphalt Concrete Layers Applied to Milled Surfaces in Virginia
    10-1527 Can More Reclaimed Asphalt Pavement Be Added? A Study of Extracted Binder Properties from Plant-Produced Mixtures with up to 25% Reclaimed Asphalt Pavement
    10-1630 Evaluation of Probing Versus Coring for Determination of Portland Cement Concrete Pavement Thickness
    10-1704 CRCP Forensic Investigations and Remedial Actions in Virginia
    10-2170 Bulk Specific Gravity of Reclaimed Asphalt Pavement Aggregate: Evaluating the Effect on Voids in Mineral Aggregate

    Data and Information Systems

    10-1768 Improving Road Weather Hazard Products with Vehicle Probe Data: Vehicle Data Translator Quality-Checking Procedures
    10-3060 Diagnosing Road Weather Conditions with Vehicle Probe Data: Results from Detroit IntelliDrive Field Study

    Design

    10-0087 New Test Level 2 Rough Stone Masonry Guardwall
    10-0431 Termination and Transition of Temporary Concrete Barrier
    10-0985 Trackless Tack Coat Materials: Laboratory Evaluation for Performance Acceptance
    10-1050 Bond Expectations for Asphalt Concrete Layers Applied to Milled Surfaces in Virginia
    10-2189 Limits of Acceptable Rail-and-Post Deflection in Crash-Damaged Strong-Post W-Beam Guardrail
    10-2303 Low-Profile Barrier with TL-3 Modification
    10-2621 Criteria for Passing Sight Distance for Roadway Design and Marking
    10-2804 Roadway Departure and Impact Conditions
    10-3278 Determining Lengths of Left-Turn Lanes at Signalized Intersections Under Different Left-Turn Signal Schemes
    10-3391 Development of Guidelines for Anchor Design for High-Tension Cable Guardrails
    10-3966 Application of Precast Concrete Barrier Adjacent to Steep Roadside Slope

    Freight Systems

    10-0559 Network Competition and Effects of Open Skies in Transatlantic Aviation

    Geology and Earth Materials

    10-0317 Energy Efficiency and Rod Length Effect in Standard Penetration Test Hammers
    10-0480 Investigation and Implications of Mechanically Stabilized Earth Wall Corrosion in Nevada
    10-0550 Evaluation of Characterization and Performance Modeling of Cementitiously Stabilized Layers in the Mechanistic-Empirical Pavement Design Guide
    10-1168 Implementation of Stabilized Blended Calcium Sulfate Materials in Flexible Pavement Design and Construction
    10-1755 Mechanistic Laboratory Evaluation and Field Construction of Recycled Concrete Materials for Use in Road Substructures
    10-2215 Selective Flexible Pavement Rehabilitation Based on Forensic Investigation and Deflection Analysis: Seventeen-Year Case Study in Virginia
    10-2278 Quantifying Effects of Particle Shape and Type and Amount of Fines on Unbound Aggregate Performance Through Controlled Gradation
    10-2379 Variability in Construction of Cement-Treated Base Layers: Material Properties and Contractor Performance
    10-2435 Optimum Use of Local Material for Roadway Base and Subbase
    10-2620 Investigation of the Use of Limestone Screenings in Roadway Construction
    10-2738 Detecting Voids Under Pavements: Update on Approach of U.S. Department of Defense
    10-3582 Analysis Method for Drilled Shaft-Stabilized Slopes Using Arching Concept
    10-3825 Variability in Resilient Modulus of Reclaimed Asphalt Pavement as Base Layer and Its Impact on Flexible Pavement Performance

    Infrastructure Preservation

    10-0992 Fiber-Reinforced Polymer Pile Repair Incorporating Cathodic Protection
    10-1741 Failure and Repair of Deck Closure Pour on Interstate 81
    10-2214 Use of Corrosion-Resistant Reinforcement as a Sustainable Technology for Bridge Deck Construction
    10-2736 Compaction of Noise-Reducing Asphalt Mixtures in the Laboratory
    10-3951 Feasibility of Stainless Steel as Bridge Deck Reinforcement Material: Sensitivity of Life-Cycle Evaluation to Key Analysis Variables

    Investing in Our Transportation Future – BOLD Ideas to Meet BIG Challenges

    10-3313 Effect of Frequency of Pavement Condition Data Collection on Performance Prediction
    10-4064 New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center

    Maintenance

    10-0741 Implementation of Structural Control Measures to Mitigate Avalanche Hazard Along Transportation Corridors
    10-0992 Fiber-Reinforced Polymer Pile Repair Incorporating Cathodic Protection
    10-1741 Failure and Repair of Deck Closure Pour on Interstate 81
    10-2214 Use of Corrosion-Resistant Reinforcement as a Sustainable Technology for Bridge Deck Construction
    10-2736 Compaction of Noise-Reducing Asphalt Mixtures in the Laboratory
    10-3951 Feasibility of Stainless Steel as Bridge Deck Reinforcement Material: Sensitivity of Life-Cycle Evaluation to Key Analysis Variables

    Management and Leadership

    10-0471 Agency-Initiated Bus Noise Reduction for Los Angeles Metro Orange Line
    10-4064 New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center
    10-4092 Mitigating Excessive Idling of Transit Buses

    Operations

    10-0741 Implementation of Structural Control Measures to Mitigate Avalanche Hazard Along Transportation Corridors
    10-1768 Improving Road Weather Hazard Products with Vehicle Probe Data: Vehicle Data Translator Quality-Checking Procedures
    10-2736 Compaction of Noise-Reducing Asphalt Mixtures in the Laboratory
    10-3060 Diagnosing Road Weather Conditions with Vehicle Probe Data: Results from Detroit IntelliDrive Field Study

    Pavement Management

    10-0164 Expert System for Design of Low-Volume Roads over Expansive Soils
    10-0434 Influence of Reclaimed Asphalt Pavement on Surface Friction
    10-0480 Investigation and Implications of Mechanically Stabilized Earth Wall Corrosion in Nevada
    10-0550 Evaluation of Characterization and Performance Modeling of Cementitiously Stabilized Layers in the Mechanistic-Empirical Pavement Design Guide
    10-0710 Local Calibration of Mechanistic-Empirical Pavement Design Guide Rutting Model for Minnesota Road Research Project Test Sections
    10-0794 Bonded Whitetopping Overlay Design Considerations for Prevention of Reflection Cracking, Joint Sealing, and the Use of Dowel Bars
    10-1086 Relative Effectiveness of Grooves in Tire and Pavement in Reducing Vehicle Hydroplaning Risk
    10-1542 Exploring Sustainable Pavement Rehabilitation: Cold In-place Recycling with Expanded Asphalt Mix
    10-1669 Longitudinal Joint Data Collection Efforts in Virginia Between 2005 and 2009
    10-1724 Comparative Performance of Conventional Cold In-place Recycling to Cold In-place Recycling with Expanded Asphalt: Ontario’s Experience
    10-1739 Full-Scale Field Testing for Injected Foam Stabilization of Portland Cement Concrete Repairs
    10-1938 CalME: A Mechanistic-Empirical Program to Analyze and Design Flexible Pavement Rehabilitation
    10-2209 Performance of Recycled Hot-Mix Asphalt Overlays in Rehabilitation of Flexible Pavements
    10-2215 Selective Flexible Pavement Rehabilitation Based on Forensic Investigation and Deflection Analysis: Seventeen-Year Case Study in Virginia
    10-2220 Development of a Global Positioning System-Based Vehicle Tracking System for the Minnesota Road Research Facility
    10-2272 Integration of Mechanistic-Empirical Pavement Design Guide Distresses with Local Performance Indices
    10-2278 Quantifying Effects of Particle Shape and Type and Amount of Fines on Unbound Aggregate Performance Through Controlled Gradation
    10-2333 Speed Adjustment Factors for Locked-Wheel Skid Trailer Measurements
    10-2355 Calibrating the MEPDG Permanent Deformation Performance Model for Different Maintenance and Rehabilitation Strategies
    10-2379 Variability in Construction of Cement-Treated Base Layers: Material Properties and Contractor Performance
    10-2381 Expedient Spall Repair Methods and Equipment for Airfield Pavements
    10-2395 Use of Pavement Management Information System for Verification of Mechanistic-Empirical Pavement Design Guide Performance Predictions
    10-2435 Optimum Use of Local Material for Roadway Base and Subbase
    10-2604 Long-Term Performance of Dowel Bar Retrofit in Washington State
    10-2620 Investigation of the Use of Limestone Screenings in Roadway Construction
    10-2657 Development of Maintenance Strategies to Mitigate Bridge End Damage from Water Intrusion
    10-2738 Detecting Voids Under Pavements: Update on Approach of U.S. Department of Defense
    10-2776 Updating the Pavement Design Catalog for Washington State Department of Transportation: Using 1993 AASHTO Guide, Mechanistic-Empirical Pavement Design Guide, and Historical Performance
    10-2941 Necessary Assessment of Use of State Pavement Management System Data in Mechanistic-Empirical Pavement Design Guide Calibration Process
    10-3313 Effect of Frequency of Pavement Condition Data Collection on Performance Prediction
    10-3331 Experimental Short-Wavelength Surface Textures in Portland Cement Concrete Pavements
    10-3554 Stiffness Characterization of Reinforced Asphalt Pavement Structures Built over Soft Organic Soils
    10-3565 Runway Instrumentation and Response Measurements
    10-3726 Assessment of Data Quality for Evaluations of Manual Pavement Distress

    Pedestrians and Cycles

    10-3437 Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey

    Public Transportation and Ferries

    10-0471 Agency-Initiated Bus Noise Reduction for Los Angeles Metro Orange Line
    10-3437 Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey
    10-4092 Mitigating Excessive Idling of Transit Buses

    Research and Education

    10-4064 New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center

    Safety

    10-0087 New Test Level 2 Rough Stone Masonry Guardwall
    10-0431 Termination and Transition of Temporary Concrete Barrier
    10-0741 Implementation of Structural Control Measures to Mitigate Avalanche Hazard Along Transportation Corridors
    10-1768 Improving Road Weather Hazard Products with Vehicle Probe Data: Vehicle Data Translator Quality-Checking Procedures
    10-2189 Limits of Acceptable Rail-and-Post Deflection in Crash-Damaged Strong-Post W-Beam Guardrail
    10-2303 Low-Profile Barrier with TL-3 Modification
    10-2804 Roadway Departure and Impact Conditions
    10-3060 Diagnosing Road Weather Conditions with Vehicle Probe Data: Results from Detroit IntelliDrive Field Study
    10-3391 Development of Guidelines for Anchor Design for High-Tension Cable Guardrails
    10-3966 Application of Precast Concrete Barrier Adjacent to Steep Roadside Slope

    Soil Mechanics

    10-0317 Energy Efficiency and Rod Length Effect in Standard Penetration Test Hammers
    10-0480 Investigation and Implications of Mechanically Stabilized Earth Wall Corrosion in Nevada
    10-0550 Evaluation of Characterization and Performance Modeling of Cementitiously Stabilized Layers in the Mechanistic-Empirical Pavement Design Guide
    10-1168 Implementation of Stabilized Blended Calcium Sulfate Materials in Flexible Pavement Design and Construction
    10-1653 Characterization of Two-Layer Soil System Using a Light Weight Deflectometer with Radial Sensors
    10-1755 Mechanistic Laboratory Evaluation and Field Construction of Recycled Concrete Materials for Use in Road Substructures
    10-2267 Implementation of Quality Management of Base Materials with Seismic Methods: Case Study in Texas
    10-2379 Variability in Construction of Cement-Treated Base Layers: Material Properties and Contractor Performance
    10-2657 Development of Maintenance Strategies to Mitigate Bridge End Damage from Water Intrusion
    10-2738 Detecting Voids Under Pavements: Update on Approach of U.S. Department of Defense
    10-3554 Stiffness Characterization of Reinforced Asphalt Pavement Structures Built over Soft Organic Soils
    10-3582 Analysis Method for Drilled Shaft-Stabilized Slopes Using Arching Concept
    10-3825 Variability in Resilient Modulus of Reclaimed Asphalt Pavement as Base Layer and Its Impact on Flexible Pavement Performance

    Structures

    10-0747 Seismic Design Recommendations for Steel Girder Bridges with Integral Abutments
    10-0992 Fiber-Reinforced Polymer Pile Repair Incorporating Cathodic Protection
    10-1599 Flexural Behavior and Design with High-Strength Bars and Bars Without a Well-Defined Yield Point
    10-1653 Characterization of Two-Layer Soil System Using a Light Weight Deflectometer with Radial Sensors
    10-1741 Failure and Repair of Deck Closure Pour on Interstate 81
    10-2214 Use of Corrosion-Resistant Reinforcement as a Sustainable Technology for Bridge Deck Construction
    10-2267 Implementation of Quality Management of Base Materials with Seismic Methods: Case Study in Texas
    10-3951 Feasibility of Stainless Steel as Bridge Deck Reinforcement Material: Sensitivity of Life-Cycle Evaluation to Key Analysis Variables

    Users

    10-0471 Agency-Initiated Bus Noise Reduction for Los Angeles Metro Orange Line
    10-3437 Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey
    10-4092 Mitigating Excessive Idling of Transit Buses


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    AICP Certification Maintenance Session

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    10-3437 - Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey
    Session 313
    Carsharing has grown considerably in North America during the past decade and has flourished within metropolitan regions across the United States and Canada. The result has been a new transportation landscape, which offers urban residents an alternative to automobility without car ownership. As carsharing has expanded, there has been a growing demand to understand its environmental impacts. This paper presents the results of a North American carsharing member (N = 6,281) survey. The authors establish a “before-and-after” analytical design with a specific focus on carsharing’s impacts on household vehicle holdings and the aggregate vehicle population. The results show that carsharing members reduce their vehicle holdings to a degree that is statistically significant. The average vehicles per household of the sample drops from 0.47 to 0.24. Most of this shift constitutes one-car households becoming carless. The average fuel economy of vehicles shed by carsharing households is on average 10 miles per gallon (mpg)/16 kilometers per gallon (kmpg) less than the carsharing vehicle most often used by respondents. The median age of vehicles shed by carsharing households is 11 years, but the distribution covers a considerable range. A sensitivity analysis of the sample with respect to the membership population suggests that carsharing has taken between 75,000 to 94,000 vehicles off the road, which equates to 9 to 12 vehicles (including shed and postponed auto purchases) for each carsharing vehicle.
         Elliot W. Martin, University of California, Berkeley, elliot@berkeley.edu
         Susan A. Shaheen, University of California, Berkeley
         Jeffrey R. Lidicker, University of California, Berkeley

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    10-4064 - New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center
    Session 317
    From September 2008 to April 2009, the New York Metropolitan Transportation Council collaborated with the NYU Wagner Rudin Center on a unique program to offer training courses to professional transportation staff from regional transportation agencies. The Program consisted of 23 courses organized within three distinct modules, Skill Building, Transportation Policy, and Tools and Methods. Tailored for line and mid-level staff as a parallel and complimentary track to the already established NYMTC Executive Education Program developed in the 1990s, 86% of Program participants reported the curriculum to be of strong content and with high relevance to their jobs and professional development. The Program offers a model for MPO and university research center collaboration on continuing professional education for transportation professionals. Connecting agencies through MPOs with university educational resources aligns the training goals to the MPO's regional objectives as well as national transportation education initiatives.
         Lina  Duran, NYU Wagner Rudin Center for Transportation Policy and Management, linaduran@nyu.edu
         Adam  Gromis, NYU Wagner Rudin Center for Transportation Policy and Management
         Kuo-Ann  Chiao, New York Metropolitan Transportation Council

     

    Aviation

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    10-0559 - Network Competition and Effects of Open Skies in Transatlantic Aviation
    Session 276
    This paper examines how competition in the transatlantic aviation market has evolved over the last decade and evaluates the effects of Open Skies agreements on service levels in specific U.S. and European markets. Our route analysis reveals that, in aggregate since 2000, transatlantic routes have seen an increase in number of competitors. U.S. carriers have gained a disproportionate share of new transatlantic service, leveraging the network effects of flying from their hubs. In our analysis of the effects of Open Skies between European countries and the U.S., we find that the agreements have resulted in both increases and decreases in service levels. Of the 22 European countries with U.S. Open Skies agreements in place by 2007, only seven demonstrated overall increases in service levels while six demonstrated overall reductions. Five countries saw no significant change and the remaining four have yet to receive direct transatlantic service, suggesting that liberalization alone does not oblige service level increases.
         Alex  Cosmas, Booz Allen Hamilton, acosmas@alum.mit.edu
         Peter  Belobaba, Massachusetts Institute of Technology
         William  Swelbar, Massachusetts Institute of Technology

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    10-1357 - Regional Cooperation, Coordination, and Communication Between Airports During Disasters
    Session 436
    Regional cooperation, coordination, and communication among airports can promote preparedness and continuity of operations during disasters. Interviews at 20 U.S. airports ranging in size from the smallest commercial airports to major international airports led to workshops in South Florida, New England, and Minnesota, in which representatives of airports, airlines, local responders, state agencies, and federal agencies discussed needs, opportunities, and barriers to increased regional cooperation, coordination, and communication. Qualitative analysis of the discussions led to a number of recommendations. Increased regional cooperation, coordination, and communication among airports and between regional groups of airports and other responding or regulatory agencies are highly desirable goals. Different regions of the country have different methods in place, but none is fully optimized. Interstate mutual aid among airports (SEADOG and WESTDOG, for example) has different issues than intrastate arrangements. Intrastate arrangements may need new state legislation to provide liability coverage and reimbursement. Airports in New England and the Midwest seem interested in the airport disaster operations group (DOG) approach. In Florida, the Florida Emergency Management Agency already provides strong intrastate coordination among counties and local agencies including airports. In New England, the primary interest is interstate, not intrastate. A yet-unformed national umbrella organization could coordinate the regional DOGs and serve as EMAC's aviation coordination function. TSA, FAA, and CDC have current initiatives that will assist airports during disasters.The FAA's new Advisory Circular 150/2300-31C opens an opportunity to expand regional airport cooperation and airport-community preparedness. This study makes eleven specific recommendations to improve regional cooperation among airports during disasters.
         James Fielding Smith, American Public University System, jfsmith@swva.net

     

    Bituminous Materials

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    10-0434 - Influence of Reclaimed Asphalt Pavement on Surface Friction
    Session 505
    Reclaimed asphalt pavement (RAP) is currently a widely used material for the construction of asphalt pavements. However, in regions deficient in non-polishing aggregates, RAP is not commonly allowed in mainline surface courses for high volume roadways because of friction performance concerns. The goal of the present study was to determine the maximum amount of RAP that can be blended with high friction aggregates and used in surface mixes without significantly impacting their frictional properties. The initial part of the study described here included a comparison of RAPs collected from six different sources (mix plant stockpiles) in Indiana. It was shown that the field-collected RAP’s exhibited fairly consistent properties in terms of their gradations and binder contents. In the second part of the study, low friction aggregate (limestone) was used to produce a “worst case scenario” RAP, for evaluation of its influence on frictional characteristics of two types of hot mix asphalt mixtures: (a) dense graded asphalt (DGA), and (b) stone matrix asphalt (SMA). The DGA and SMA mixtures were produced with various amounts of this “laboratory-produced” RAP. The RAP was blended with two types of highly friction resistant aggregates: steel slag and air cooled blast furnace slag. Overall, the results suggest that for the materials and mixtures studied the maximum amount (threshold level) of RAP, which can be used in surface mixes without detrimental effect on their frictional properties, was about 30%. That addition level did not seem to depend on the type of aggregate present in RAP.
         Karol J. Kowalski, Warsaw University of Technology, Poland, k.kowalski@il.pw.edu.pl
         Rebecca S. McDaniel, Purdue University
         Jan  Olek, Purdue University

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    10-0710 - Local Calibration of Mechanistic-Empirical Pavement Design Guide Rutting Model for Minnesota Road Research Project Test Sections
    Session 505
    The AASHTO interim Mechanistic-Empirical Pavement Design Guide (MEPDG) was recently introduced in the United States. Many State agencies have conducted validation and local calibration of the MEPDG performance prediction models. In this study, time history rutting performance data for pavement sections at the Minnesota Department of Transportation (Mn/DOT) full-scale pavement research facility (MnROAD) have been used for an evaluation and local calibration of the MEPDG rutting model. A detailed comparison of the predicted total rutting, asphalt layer rutting, and measured rutting is presented. The paper discusses why a conventional MEPDG model calibration was not found to feasible and recommends a modification of the rutting model. It was found that the locally calibrated model greatly improved the MEPDG rutting prediction for various pavement designs in MnROAD conditions.
         Kyle  Hoegh, University of Minnesota, hoeg0021@umn.edu
         Lev  Khazanovich, University of Minnesota
         Maureen  Jensen, Minnesota Department of Transportation

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    10-0985 - Trackless Tack Coat Materials: Laboratory Evaluation for Performance Acceptance
    Session 375
    During the design of a pavement structure, the engineer assumes the loads applied by traffic will be distributed in such a manner that minimizes pavement distress. For flexible pavements, the impacts of the loadings are reduced by using high quality materials in the asphalt bound layers at a designed thickness in order to minimize fatigue cracking in the bottom of the asphalt concrete section and rutting in the top of the subgrade. However, when the engineer makes this assumption, they design for a “no slip” (i.e. bonding) condition between asphalt concrete layers resulting in a monolithic structure. Unfortunately, the “no slip” condition is not always provided during construction. While the importance of the bond is known during pavement design, the use of tack coat materials in the field is often omitted or not applied at the specified application rate. The predominant reason for not following the specifications is the tracking of tack onto adjacent pavements. Tracking results in build up at intersections and covering of permanent pavement markings. This leads to additional costs to the contractor as well as safety concerns. Unfortunately, the cost to the pavement’s owner for not achieving good bond is much higher due to premature functional and structural failures. For certain applications, VDOT will specify the use of a tack coat material that meets its special provision for non-tracking tack. This special provision was developed based on experience with one material. Since developed, additional suppliers have provided materials for consideration and acceptance as trackless tack. This paper will outline the approach VDOT used to assess each material and the testing results. This paper will provide conclusions as well as recommendations for future research.
         Trenton  Clark, Virginia Asphalt Association, tclark@vaasphalt.com

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    10-1050 - Bond Expectations for Asphalt Concrete Layers Applied to Milled Surfaces in Virginia
    Session 375
    This paper describes a field study of the effect of tack on bond strength between a new asphalt concrete overlay and a milled surface. The study was a supporting activity to a program of research designed to identify a test method and acceptance criteria for bonding of asphalt concrete layers. The findings of the study led to the recommendation that the Virginia Department of Transportation no longer require the practice of tacking primary horizontal surfaces when placing a new overlay on a milled surface. An analysis of the costs associated with conventional tack use found that the material cost per lane-mile is between $572 and $836. A review of the typical “mill and fill” paving activity (maintenance) for the 2008 season found that VDOT would save between $488,000 and $650,000 per year by foregoing conventional tacking on milled horizontal surfaces. If the tacking material is of the non-tracking variety, which is becoming more and more common, the savings could be as much as $950,000 per year.
         Kevin Kenneth McGhee, Virginia Center for Transportation Innovation and Research, Kevin.McGhee@VDOT.Virginia.gov
         Trenton  Clark, Virginia Asphalt Association

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    10-1168 - Implementation of Stabilized Blended Calcium Sulfate Materials in Flexible Pavement Design and Construction
    Session 243
    The Blended Calcium Sulfate (BCS), a recycled fluorogypsum waste material, has been used in Louisiana as a pavement base layer for more than a decade. Without further chemical stabilization, the major concern of using raw BCS as a pavement structural layer is its moisture susceptibility. It could cause both short-term construction difficulties and long-term performance problems. In order to improve the moisture susceptibility of BCS, various cementitious agents were used in the laboratory for BCS stabilization. To further verify the efficiency of BCS stabilization schemes obtained from laboratory and assess the field performance for stabilized BCS materials as well as potential cost benefits, three pavement test sections were constructed and tested using the Accelerated Loading Facility (ALF) device. Both laboratory and field test results indicated that a grade 120 granulated ground blast furnace slag (GGBFS) of 10 percent by volume stabilized BCS material possessed a superior performance over raw BCS in terms of water resistance, durability and good long-term performance. Field test results further demonstrated that the GGBFS stabilized BCS base outperformed both a regular crushed stone base and a fly ash stabilized BCS base by a significantly large margin. A life-cycle cost analysis proved that, besides its outstanding laboratory and field performance, using the GGBFS stabilized BCS can provide a substantial long-term savings over regular crushed stone and fly ash stabilized BCS bases in a 30-year pavement design life period.
         Zhong  Wu, Louisiana Transportation Research Center, zhongwu@ltrc.lsu.edu
         Zhongjie  Zhang, Louisiana Department of Transportation and Development
         Mingjiang  Tao, Worcester Polytechnic Institute

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    10-1527 - Can More Reclaimed Asphalt Pavement Be Added? A Study of Extracted Binder Properties from Plant-Produced Mixtures with up to 25% Reclaimed Asphalt Pavement
    Session 502
    This paper presents the results of a study conducted by the New Hampshire Department of Transportation (NHDOT) in cooperation with three local paving contractors. Plant-produced HMA mixtures containing RAP percentages from 0% to 25% were obtained from seven different batch plants. A total of 28 mixtures were sampled and sent to the binder testing laboratories at NHDOT and Pike Industries, Inc. The virgin binders were also sampled and sent for binder testing. Binders were extracted and recovered from all of the mixtures and were tested to determine the PG binder grade and critical cracking temperature. The effect of the RAP at various percentages on the binder properties was evaluated. The high-end PG grades were found to remain the same or only increase one grade for the mixtures tested. The low-end PG grades also remained the same or only bumped one grade, and the critical cracking temperatures only changed by a few degrees for the mixtures examined in this study. The results of this study lead to a change in the implementation of the new NHDOT specification regarding the use of recyled asphalt binder in HMA.
         Jo Sias Daniel, University of New Hampshire, jo.daniel@unh.edu
         Jeffrey L Pochily, Pike Industries, Inc
         Denis M Boisvert, New Hampshire Department of Transportation

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    10-1755 - Mechanistic Laboratory Evaluation and Field Construction of Recycled Concrete Materials for Use in Road Substructures
    Session 243
    Conventional flexible pavement systems require significant volumes of quality aggregates. Unfortunately, most urban centres are faced with depleted aggregate sources. Given recent significant urban infrastructure renewal as well as increased costs associated with landfilling concrete rubble, there is potential to optimize the reclamation and recycling of Portland cement concrete (PCC) and hot mix asphalt concrete (HMAC) rubble through innovative use of these materials in road rehabilitation. The primary objective of this study was to demonstrate the ability to reclaim, process, and recycle stockpiled concrete materials in order to provide improved structural mechanistic-climatic material properties. As part of this objective, it is desirable to meet or exceed the mechanical properties of conventional granular road materials. This research is based on advancements of the “Green Streets” Infrastructure Program in the City of Saskatoon. A second objective of this research was to pilot the field application of reclaimed and recycled asphaltic concrete and PCC rubble in a typical urban road reconstruction application. Recycled HMAC and PCC materials were used in a pilot re construction project of a road exhibiting substructure moisture problems and structural failure. This study showed that recycled HMAC and PCC rubble materials could be processed to achieve mechanistic laboratory properties that exceed those of conventional granular base materials. This study also demonstrated efficient constructability and high end-product structural value of a typical rehabilitated urban road structure test section in the City of Saskatoon utilizing recycled HMAC and PCC rubble.
         Curtis F. Berthelot Ph.D.,P.Eng., University of Saskatchewan, Canada, curtis.berthelot@usask.ca
         Rielle  Haichert, PSITechnologies Inc., Canada
         Diana  Podborochynski, Pavement Scientific International, Canada
         Colin  Wandzura, PSI Technologies, Inc., Canada
         Brian  Taylor P.Eng., Consultant, Canada
         Duane Joel Guenther, City of Saskatoon, Canada

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    10-2170 - Bulk Specific Gravity of Reclaimed Asphalt Pavement Aggregate: Evaluating the Effect on Voids in Mineral Aggregate
    Session 502
    Several methods are available for determining the bulk specific gravity (Gsb) of reclaimed asphalt pavement (RAP). However, there has not been a clear recommendation for determining this property. In this study, asphalt mixes with known aggregate properties were produced and aged in the laboratory to simulate RAP. The aggregates were recovered and the aggregate properties, including Gsb, were reassessed. The aged mixtures were also tested to determine maximum theoretical specific gravity (Gmm), from which estimated Gsb values could be calculated. The Gsb values from both the extraction methods and Gmm method were compared to the known or “true” Gsb values for these aggregates. The effects of the RAP Gsb errors on VMA from the various methods were also evaluated. Based on the results of this study, it is recommended that the Gmm method be used to determine the RAP Gsb when a regional absorption value is known.
         Andrea  Kvasnak, National Center for Asphalt Technology, ank0004@auburn.edu
         Randy C. West, National Center for Asphalt Technology
         Jenna  Michael, MeadWextvaco Corporation
         Luis  Loria-Salazar, University of Costa Rica
         Elie Y Hajj, University of Nevada, Reno
         Nam  Tran, National Center for Asphalt Technology

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    10-3825 - Variability in Resilient Modulus of Reclaimed Asphalt Pavement as Base Layer and Its Impact on Flexible Pavement Performance
    Session 243
    The use of reclaimed asphalt pavement (RAP) as a base layer is gaining popularity, but there are gaps in the literature about the material performance. One problem that has not been well investigated is the variability in the resilient modulus (MR) of RAP as a base layer compared to typical granular material, and the impact of this variability on pavement performance. In addition to the expected variability in MR of the base layer resulting from the use of aggregates that have different qualities, the process of selecting one MR value has its own variability. This paper investigates the effect of three sources of variability in determining the base layer resilient modulus in the laboratory for RAP compared to granular material. The first source that was considered is the variability in the material and sample preparation for the MR testing. The second source of variability is the constitutive model used to predict the resilient modulus. The third source is the state of stress used to predict the base layer modulus. The study compares the variability of MR of RAP to MR of unbound granular materials based on actual testing results. The impact of MR variability for RAP compared to granular material on the flexible pavement distresses is investigated using the Mechanistic-Empirical Pavement Design Guide (MEPDG).
         Mohamed Ibrahim El-Sharkawi Attia, Zagazig University, Egypt
         Magdy  Abdelrahman, North Dakota State University, m.abdelrahman@ndsu.edu

     

    Concrete Materials

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    10-1042 - Scaling Resistance of Concrete Containing Slag Cement: Critical Review
    Session 242
    Concrete containing slag cement (i.e., interground with clinker or replacing ordinary portland cement) has been widely used for many years and has provided proven long-term performance. On the other hand, there are concerns about the deicer salt scaling resistance of concrete containing high amounts of slag (e.g., 50% and up). These concerns are generally based on laboratory results obtained from ASTM C672 procedure. However, laboratory results are not generally consistent with field observations. A literature survey has been conducted to compile laboratory data from reported ASTM C672 tests along with field performance data. The objective was to seek evidence that would support the selection of an upper limit for slag dosage in concrete that will be exposed to deicer salts. The findings were that when using up to 50% slag it is possible to produce concrete that is resistant to salt scaling. However, slag content is not the sole factor controlling scaling resistance but construction related issues such as finishing and curing are also significant. In addition, the current ASTM C672 procedure reportedly does not reliably predict field performance of concrete containing slag.
         Fatih  Bektas, Iowa State University, fbektas@iastate.edu
         Peter C. Taylor, Iowa State University
         Kejin  Wang, Iowa State University

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    10-1630 - Evaluation of Probing Versus Coring for Determination of Portland Cement Concrete Pavement Thickness
    Session 240
    The Wisconsin Department of Transportation (WisDOT) has used contractor probing measurement of fresh Portland Cement Concrete Pavement (PCCP) to determine pavement thickness since 1998. Prior to that, WisDOT used coring to measure thickness and determine payment for pavement. The probing method is non-destructive and has financial advantages for WisDOT, as it eliminates the costs of coring and reduces the expenses of contract administration. Probing also provides the contractor with immediate feedback on the depth of the pavement being constructed. A study was conducted to verify the reliability of probing measurement for determining pavement thickness, as well as verifying contractors’ compliance with design requirements. To determine whether probing was still a viable method for use by WisDOT in construction contract administration, core depths were compared to field measured probe depths for twelve projects constructed between 2006 and 2008 across the state of Wisconsin. Sample means were compared, statistically calculated estimates of differences were examined, and a statistical analysis at the 95% confidence interval was carried out. Based upon these analyses, probing does provide an acceptable measure of pavement thickness. All contractor probe measurements and over 80% of the WisDOT core samples showed that constructed pavement thickness exceeded the design thickness.
         Haidy Gerges Nasief, University of Wisconsin, Madison, eng.haidy@yahoo.com
         Gyude W. Allison, University of Wisconsin, Madison
         Gary C. Whited, University of Wisconsin, Madison
         Awad S. Hanna Ph.D., P.E., University of Wisconsin, Madison

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    10-1631 - New AASHTO T336-09 Coefficient of Thermal Expansion Test Method: How Will It Affect You?
    Session 241
    Although a large amount of papers were published in the past few years on the coefficient of thermal expansion (CTE) and its impact in concrete pavement design, just recently an error was discovered in the AASHTO TP 60-00 regarding the calibration of the testing equipment and consequently, on the determination of the concrete CTE. The new AASHTO T 336-09, even though it was based on the TP 60-00, rectifies this calibration issue. This paper presents the differences between the two test methods and its implications on the Long Term Pavement Performance (LTPP) database, on the mechanistic-empirical pavement design guide (MEPDG) and its implementation by the State DOTs. It also provides recommendations for improvements to the T 336-09 test method.
         Jussara  Tanesi Ph.D., SES Group & Associates, LLC, jussara.tanesi.ctr@dot.gov
         Gary L. Crawford, Federal Highway Administration
         Mihai  Nicolaescu, Global Consulting, Inc.
         Richard C. Meininger, Federal Highway Administration
         Jagan M. Gudimettla P.E., Federal Highway Administration

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    10-1704 - CRCP Forensic Investigations and Remedial Actions in Virginia
    Session 240
    ABSTRACT The key to attaining a long lasting, safe, and economical Continuously Reinforced Concrete Pavement (CRCP) or any other pavement is learning from its performance. Pavement performance is dependent on the characteristics of the materials, the pavement design, and the construction practice used. Therefore, it makes good sense to trace the impact of these elements to identify issues and then to develop a plan of action leading to a high-performing CRCP. Virginia’s plan of action was formulated using all the available talent in several areas, including pavement design, materials selection and testing, research, and the construction practices. The close cooperation with the concrete industry was essential for success. The collective effort resulted in a better understanding of the failure mechanisms, good performance and the interaction among the several factors involved in constructing long-lasting CRCP with minimal maintenance. This paper highlights forensic investigations and lessons learned from CRCP projects in the past and how the findings are applied to recently constructed CRCP pavements.
         Mohamed Khamis Elfino, VIrginia Department of Transportation, mohamed.elfino@vdot.virginia.gov
         Celik  Ozyildirim, Virginia Center for Transportation Innovation and Research
         Harikrishnan  Nair P.E, Virginia Center for Transportation Innovation and Research

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    10-2374 - Development of End-Result Specifications for Concrete in Virginia
    Session
    The purpose of this study was to describe the development of the Virginia Department of Transportation’s (VDOT) end result specifications (ERS) for hydraulic cement concrete. The work comprised two phases. In Phase 1, a special provision was developed and applied to two pilot projects. In Phase 2, the special provision was applied to more pilot projects from different districts across Virginia. Pay adjustments were not applied for the pilot projects; VDOT’s current specifications were applied for acceptance and rejection. The ERS have three parts. The first part introduces process control measures. The contractor is responsible for the concrete design and is required to provide a quality control plan. The plan addresses all elements that affect quality, including mixture designs, aggregate sources, ingredients, tests and testing frequency, fresh and hardened concrete properties, and control charts. The second part covers the mixture design approval by VDOT. The third part covers project acceptance, which includes pay adjustments depending on test results. The pilot projects are continuing; however, some of the features of the ERS are already permitted if requested by the contractor and approved by the project engineer, such as using combined cementitious material, using combined aggregates, mixing gravel and crushed stone, combining retarding admixtures and water-reducing admixtures, using curing boxes with continuously recording thermometers, and exceeding the 300 revolution limit or the time limit of 1.5 hours from the addition of water.
         Celik  Ozyildirim, Virginia Center for Transportation Innovation and Research, celik@VDOT.Virginia.gov

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    10-2943 - Alkali-Silica Reactivity Prevention in U.S. Department of Defense
    Session 242
    Supplementary cementitious materials (SCM) are used in concrete to prevent alkali silica reactivity (ASR) in Department of Defense (DOD) concrete construction. To insure that deleterious expansion does not take place, the DOD specifications rely primarily on ASTM C 1260 and C 1567. For airfield pavements, the threshold expansion indicative of ASR potential was conservatively set to 0.08% after 28 days of exposure. In this paper, the rationale for the reliance on these tests is explained, as well as the choice for the threshold expansion. The approach for ASR prevention, currently being expanded to all concrete construction, is also detailed.
         Luis Javier Malvar, U.S. Navy Engineering Service Center, luis.malvar@navy.mil

     

    Construction

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    10-0985 - Trackless Tack Coat Materials: Laboratory Evaluation for Performance Acceptance
    Session 375
    During the design of a pavement structure, the engineer assumes the loads applied by traffic will be distributed in such a manner that minimizes pavement distress. For flexible pavements, the impacts of the loadings are reduced by using high quality materials in the asphalt bound layers at a designed thickness in order to minimize fatigue cracking in the bottom of the asphalt concrete section and rutting in the top of the subgrade. However, when the engineer makes this assumption, they design for a “no slip” (i.e. bonding) condition between asphalt concrete layers resulting in a monolithic structure. Unfortunately, the “no slip” condition is not always provided during construction. While the importance of the bond is known during pavement design, the use of tack coat materials in the field is often omitted or not applied at the specified application rate. The predominant reason for not following the specifications is the tracking of tack onto adjacent pavements. Tracking results in build up at intersections and covering of permanent pavement markings. This leads to additional costs to the contractor as well as safety concerns. Unfortunately, the cost to the pavement’s owner for not achieving good bond is much higher due to premature functional and structural failures. For certain applications, VDOT will specify the use of a tack coat material that meets its special provision for non-tracking tack. This special provision was developed based on experience with one material. Since developed, additional suppliers have provided materials for consideration and acceptance as trackless tack. This paper will outline the approach VDOT used to assess each material and the testing results. This paper will provide conclusions as well as recommendations for future research.
         Trenton  Clark, Virginia Asphalt Association, tclark@vaasphalt.com

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    10-1050 - Bond Expectations for Asphalt Concrete Layers Applied to Milled Surfaces in Virginia
    Session 375
    This paper describes a field study of the effect of tack on bond strength between a new asphalt concrete overlay and a milled surface. The study was a supporting activity to a program of research designed to identify a test method and acceptance criteria for bonding of asphalt concrete layers. The findings of the study led to the recommendation that the Virginia Department of Transportation no longer require the practice of tacking primary horizontal surfaces when placing a new overlay on a milled surface. An analysis of the costs associated with conventional tack use found that the material cost per lane-mile is between $572 and $836. A review of the typical “mill and fill” paving activity (maintenance) for the 2008 season found that VDOT would save between $488,000 and $650,000 per year by foregoing conventional tacking on milled horizontal surfaces. If the tacking material is of the non-tracking variety, which is becoming more and more common, the savings could be as much as $950,000 per year.
         Kevin Kenneth McGhee, Virginia Center for Transportation Innovation and Research, Kevin.McGhee@VDOT.Virginia.gov
         Trenton  Clark, Virginia Asphalt Association

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    10-1527 - Can More Reclaimed Asphalt Pavement Be Added? A Study of Extracted Binder Properties from Plant-Produced Mixtures with up to 25% Reclaimed Asphalt Pavement
    Session 502
    This paper presents the results of a study conducted by the New Hampshire Department of Transportation (NHDOT) in cooperation with three local paving contractors. Plant-produced HMA mixtures containing RAP percentages from 0% to 25% were obtained from seven different batch plants. A total of 28 mixtures were sampled and sent to the binder testing laboratories at NHDOT and Pike Industries, Inc. The virgin binders were also sampled and sent for binder testing. Binders were extracted and recovered from all of the mixtures and were tested to determine the PG binder grade and critical cracking temperature. The effect of the RAP at various percentages on the binder properties was evaluated. The high-end PG grades were found to remain the same or only increase one grade for the mixtures tested. The low-end PG grades also remained the same or only bumped one grade, and the critical cracking temperatures only changed by a few degrees for the mixtures examined in this study. The results of this study lead to a change in the implementation of the new NHDOT specification regarding the use of recyled asphalt binder in HMA.
         Jo Sias Daniel, University of New Hampshire, jo.daniel@unh.edu
         Jeffrey L Pochily, Pike Industries, Inc
         Denis M Boisvert, New Hampshire Department of Transportation

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    10-1630 - Evaluation of Probing Versus Coring for Determination of Portland Cement Concrete Pavement Thickness
    Session 240
    The Wisconsin Department of Transportation (WisDOT) has used contractor probing measurement of fresh Portland Cement Concrete Pavement (PCCP) to determine pavement thickness since 1998. Prior to that, WisDOT used coring to measure thickness and determine payment for pavement. The probing method is non-destructive and has financial advantages for WisDOT, as it eliminates the costs of coring and reduces the expenses of contract administration. Probing also provides the contractor with immediate feedback on the depth of the pavement being constructed. A study was conducted to verify the reliability of probing measurement for determining pavement thickness, as well as verifying contractors’ compliance with design requirements. To determine whether probing was still a viable method for use by WisDOT in construction contract administration, core depths were compared to field measured probe depths for twelve projects constructed between 2006 and 2008 across the state of Wisconsin. Sample means were compared, statistically calculated estimates of differences were examined, and a statistical analysis at the 95% confidence interval was carried out. Based upon these analyses, probing does provide an acceptable measure of pavement thickness. All contractor probe measurements and over 80% of the WisDOT core samples showed that constructed pavement thickness exceeded the design thickness.
         Haidy Gerges Nasief, University of Wisconsin, Madison, eng.haidy@yahoo.com
         Gyude W. Allison, University of Wisconsin, Madison
         Gary C. Whited, University of Wisconsin, Madison
         Awad S. Hanna Ph.D., P.E., University of Wisconsin, Madison

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    10-1704 - CRCP Forensic Investigations and Remedial Actions in Virginia
    Session 240
    ABSTRACT The key to attaining a long lasting, safe, and economical Continuously Reinforced Concrete Pavement (CRCP) or any other pavement is learning from its performance. Pavement performance is dependent on the characteristics of the materials, the pavement design, and the construction practice used. Therefore, it makes good sense to trace the impact of these elements to identify issues and then to develop a plan of action leading to a high-performing CRCP. Virginia’s plan of action was formulated using all the available talent in several areas, including pavement design, materials selection and testing, research, and the construction practices. The close cooperation with the concrete industry was essential for success. The collective effort resulted in a better understanding of the failure mechanisms, good performance and the interaction among the several factors involved in constructing long-lasting CRCP with minimal maintenance. This paper highlights forensic investigations and lessons learned from CRCP projects in the past and how the findings are applied to recently constructed CRCP pavements.
         Mohamed Khamis Elfino, VIrginia Department of Transportation, mohamed.elfino@vdot.virginia.gov
         Celik  Ozyildirim, Virginia Center for Transportation Innovation and Research
         Harikrishnan  Nair P.E, Virginia Center for Transportation Innovation and Research

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    10-2170 - Bulk Specific Gravity of Reclaimed Asphalt Pavement Aggregate: Evaluating the Effect on Voids in Mineral Aggregate
    Session 502
    Several methods are available for determining the bulk specific gravity (Gsb) of reclaimed asphalt pavement (RAP). However, there has not been a clear recommendation for determining this property. In this study, asphalt mixes with known aggregate properties were produced and aged in the laboratory to simulate RAP. The aggregates were recovered and the aggregate properties, including Gsb, were reassessed. The aged mixtures were also tested to determine maximum theoretical specific gravity (Gmm), from which estimated Gsb values could be calculated. The Gsb values from both the extraction methods and Gmm method were compared to the known or “true” Gsb values for these aggregates. The effects of the RAP Gsb errors on VMA from the various methods were also evaluated. Based on the results of this study, it is recommended that the Gmm method be used to determine the RAP Gsb when a regional absorption value is known.
         Andrea  Kvasnak, National Center for Asphalt Technology, ank0004@auburn.edu
         Randy C. West, National Center for Asphalt Technology
         Jenna  Michael, MeadWextvaco Corporation
         Luis  Loria-Salazar, University of Costa Rica
         Elie Y Hajj, University of Nevada, Reno
         Nam  Tran, National Center for Asphalt Technology

     

    Data and Information Systems

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    10-1768 - Improving Road Weather Hazard Products with Vehicle Probe Data: Vehicle Data Translator Quality-Checking Procedures
    Session 211
    One of the goals of the Research and Innovative Technology Administration’s IntelliDriveSM initiative is for the public and private organizations that collect, process, and generate weather products to utilize vehicle sensor data to improve weather and road condition hazard products. It is possible that some users will not be able to — or not want to — contend with the complexities associated with vehicle data, such as data quality, representativeness, and format. With funding and support from the U.S. Department of Transportation’s (USDOT) Research and Innovative Technology Administration (RITA) IntelliDriveSM initiative and direction from the Federal Highway Administration’s (FHWA) Road Weather Management Program, the National Center for Atmospheric Research (NCAR) is conducting research to develop a Vehicle Data Translator (VDT) to address these vehicle-based data challenges. This paper first describes the VDT quality-check (QCh) concept and then examines QCh pass rates for temperature and pressure data collected from 11 specially-equipped vehicles operating in the Detroit Testbed in April 2009. Results show that temperature pass rates are higher than pressure. Additionally, pass rates are affected by vehicle type, vehicle speed, ambient temperature, and precipitation occurrence for both temperature and pressure.
         Sheldon  Drobot, National Center for Atmospheric Research, drobot@ucar.edu
         Michael Benjamin Chapman, National Center for Atmospheric Research
         Elena  Schuler, National Center for Atmospheric Research
         Gerry  Wiener, National Center for Atmospheric Research
         William Paul Mahoney III, National Center for Atmospheric Research
         Paul A. Pisano, Federal Highway Administration
         Ben  McKeever, Research and Innovative Technology Administration

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    10-3060 - Diagnosing Road Weather Conditions with Vehicle Probe Data: Results from Detroit IntelliDrive Field Study
    Session 211
    Over the past two years, the USDOT/Research and Innovative Technology Administration funded an IntelliDriveSM vehicle probe data collection testbed in the Northwest Detroit area (the Detroit Testbed). The purpose of the testbed was to provide the infrastructure for both public and private organizations to collect, process, and generate a robust observation dataset for multiple purposes (e.g., crash avoidance, automated toll services, weather diagnostics). During April 2009, a weather specific field study was performed over an 11-day period. The resulting dataset was processed by a Vehicle Data Translator (VDT), which parsed, quality controlled, and combined these data (with ancillary weather data) in the generation of road-weather specific algorithms. This paper briefly describes the VDT concept and then examines the accuracy of the quality-controlled temperature and pressure data (for several different stratifications) collected from 11 specially-equipped vehicles operated during the study time period. Results show that the vehicles accurately measure the temperature (compared with a nearby fixed weather station; KDTW), but are not as accurate at measuring the barometric pressure. In addition, stratification by speed, vehicle type, time of day, and occurrence of precipitation do not affect the accuracy of the temperature and barometric pressure measurements
         Michael Benjamin Chapman, National Center for Atmospheric Research, mchapman@ucar.edu

     

    Design

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    10-0087 - New Test Level 2 Rough Stone Masonry Guardwall
    Session 277
    A minimum mounting-height rough stone masonry guardwall was designed and successfully crash tested to meet Test Level 2 (TL-2) safety performance criteria found in NCHRP Report 350. Several design concepts were considered for providing shear transfer between the top capstones and the inner core wall. The new design utilizes steel angle segments anchored to the core wall with the upper leg recessed into saw-cuts placed in the capstones. LS-DYNA simulations were performed with varying barrier heights to evaluate the propensity for vehicular instabilities and barrier override. Two crash tests were performed. The first test was performed on a 22 in. tall guardwall using a 2000P pickup truck impacting at a speed of 44.4 mph and at an angle of 24.2 degrees. The second test was performed on a 20 in. tall guardwall using another 2000P vehicle impacting at a speed of 43.6 mph and at an angle of 24.4 degrees. Both crash tests provided acceptable safety performance. Although the 20 in. tall parapet adequately contained and redirected the pickup truck at the TL-2 conditions, barrier performance was slightly degraded over that observed in the 22 in. tall parapet. Based on the results of this study and for new construction, it is recommended that the rough stone masonry guardwall system be implemented using a nominal top mounting height of 22 in. relative to the traveled way. A significant benefit of this nominal height is that roadways requiring resurfacing could be accommodated using a 2 in. pavement overlay placed adjacent to the barrier system.
         John D. Reid, University of Nebraska, Lincoln, jreid@unl.edu
         Ronald K. Faller P.E., University of Nebraska, Lincoln

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    10-0431 - Termination and Transition of Temporary Concrete Barrier
    Session 277
    For the research studies described herein two new technologies were developed for temporary concrete barriers (TCBs). The first project developed an economical method for terminating and anchoring the upstream end of TCB systems. The second developed a TCB approach transition for attachment to permanent concrete median barriers. Both designs were configured for use with the Kansas F-shape TCB that is currently used by several states participating in the Midwest Pooled Fund Program. These efforts were performed in accordance with the Test Level 3 (TL-3) guidelines found in the Manual for Assessing Safety Hardware 2008 (MASH). The termination and anchorage system allowed for a significant reduction in the number of barrier segments required upstream from the length of need and for use in anchoring a free-standing TCB system. The anchorage system was configured to effectively constrain the end of the TCB system for impacts as far upstream as the first anchored barrier segment. Full-scale crash testing demonstrated that the impacting vehicle was safely and smoothly redirected, and the test was judged acceptable according to the TL-3 safety criteria set forth in MASH. The approach transition was developed for attaching free-standing TCBs to permanent concrete median barriers. Evaluation of the approach transition required testing at two Critical Impact Point (CIP) locations. Full-scale crash testing demonstrated that the impacting vehicle was safely and smoothly redirected, and the testing of the approach transition was judged acceptable according to the TL-3 safety criteria set forth in MASH.
         Robert  Bielenberg, University of Nebraska, Lincoln, rbielenberg2@unl.edu
         Scott K. Rosenbaugh, Midwest Roadside Safety Facility
         John D. Reid, University of Nebraska, Lincoln
         Ronald K. Faller P.E., University of Nebraska, Lincoln
         Karla A. Lechtenberg, University of Nebraska, Lincoln

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    10-0985 - Trackless Tack Coat Materials: Laboratory Evaluation for Performance Acceptance
    Session 375
    During the design of a pavement structure, the engineer assumes the loads applied by traffic will be distributed in such a manner that minimizes pavement distress. For flexible pavements, the impacts of the loadings are reduced by using high quality materials in the asphalt bound layers at a designed thickness in order to minimize fatigue cracking in the bottom of the asphalt concrete section and rutting in the top of the subgrade. However, when the engineer makes this assumption, they design for a “no slip” (i.e. bonding) condition between asphalt concrete layers resulting in a monolithic structure. Unfortunately, the “no slip” condition is not always provided during construction. While the importance of the bond is known during pavement design, the use of tack coat materials in the field is often omitted or not applied at the specified application rate. The predominant reason for not following the specifications is the tracking of tack onto adjacent pavements. Tracking results in build up at intersections and covering of permanent pavement markings. This leads to additional costs to the contractor as well as safety concerns. Unfortunately, the cost to the pavement’s owner for not achieving good bond is much higher due to premature functional and structural failures. For certain applications, VDOT will specify the use of a tack coat material that meets its special provision for non-tracking tack. This special provision was developed based on experience with one material. Since developed, additional suppliers have provided materials for consideration and acceptance as trackless tack. This paper will outline the approach VDOT used to assess each material and the testing results. This paper will provide conclusions as well as recommendations for future research.
         Trenton  Clark, Virginia Asphalt Association, tclark@vaasphalt.com

    Back to Top

    10-1050 - Bond Expectations for Asphalt Concrete Layers Applied to Milled Surfaces in Virginia
    Session 375
    This paper describes a field study of the effect of tack on bond strength between a new asphalt concrete overlay and a milled surface. The study was a supporting activity to a program of research designed to identify a test method and acceptance criteria for bonding of asphalt concrete layers. The findings of the study led to the recommendation that the Virginia Department of Transportation no longer require the practice of tacking primary horizontal surfaces when placing a new overlay on a milled surface. An analysis of the costs associated with conventional tack use found that the material cost per lane-mile is between $572 and $836. A review of the typical “mill and fill” paving activity (maintenance) for the 2008 season found that VDOT would save between $488,000 and $650,000 per year by foregoing conventional tacking on milled horizontal surfaces. If the tacking material is of the non-tracking variety, which is becoming more and more common, the savings could be as much as $950,000 per year.
         Kevin Kenneth McGhee, Virginia Center for Transportation Innovation and Research, Kevin.McGhee@VDOT.Virginia.gov
         Trenton  Clark, Virginia Asphalt Association

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    10-2189 - Limits of Acceptable Rail-and-Post Deflection in Crash-Damaged Strong-Post W-Beam Guardrail
    Session 457
    The guidelines for the testing of strong-post w-beam guardrail, intended to ensure the safety of errant vehicles, are specified in the National Cooperative Highway Research Program (NCHRP) Report 350. A limitation of these tests is that they are always performed on new, undamaged guardrail whereas guardrail along highways is in a continuous cycle of damage and repair. No tests have ever evaluated the performance of deflection-damaged guardrail. A full scale, two part crash test was conducted to evaluate the performance of a guardrail with 14.5 inches (368 mm) of prior crash damage. When this guardrail was struck by a 4409 lb (2000 kg) pickup truck traveling at 62 mph (100 kph) the vehicle vaulted and came to rest upright behind the barrier. A critical factor was the failure of a post to separate from the rails. Finite element models were employed to evaluate the guardrail performance at lower levels of deflection. The crash tests and finite element models demonstrated that post and rail deflection of 11 inches (279 mm) or higher resulted in vaulting. Repair was recommended for strong-post w-beam guardrail with combined rail and post deflection exceeding 6 inches (152 mm). This limit allows a margin of safety for variations in soil strength and vehicle height. The existence of rail only deflection had a minimal effect on the crash performance up to the maximum tested value of 6 inches.
         Carolyn E. Hampton, Virginia Polytechnic Institute and State University, champton@vt.edu
         Douglas John Gabauer, Bucknell University
         Hampton Clay Gabler, Virginia Polytechnic Institute and State University

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    10-2303 - Low-Profile Barrier with TL-3 Modification
    Session 277
    The Low-Profile Barrier (LPB) is only 20 inches high with predictably improved visibility of intersecting and/or surrounding traffic compared to the 32-inch standard safety shape. The initial LPB was developed by Texas Transportation Institute (TTI) and Texas Department of Transportation (TxDOT) in 1995 and approved by FHWA for Test Level 2 (TL-2) (45 mph) in 1997 and 1998. Since that time, it has become a standard in Texas in construction zones and also has been applied to permanent installations. Florida engineers have developed their own single-sided LPB using TTI’s profile. A new advantage has been discovered that should have a significant influence on permanent installations. Design consultants have reported spectacular potential savings in soil/rock earth work in mountainous terrain if a 20-inch LPB can be used instead of the common 32 inch safety shape. This is due to the AASHTO requirement for sight distance around horizontal curves. These applications often require TL-3 performance. TL-3 performance was achieved by using the existing LPB as the base and developing a stabilizing rail that attaches to the top of the LPB at connection points. A retrofit of the current LPB was tested for both visibility, and for pickup rollover stability, the flaw in LPB TL-2 performance. NCHRP Report 350 test 3-11 was performed on two designs to evaluate the modified barrier in containing and redirecting a pickup. This report includes details of the LPB 3 testing.
         Jeremy  Klam, Texas A&M Transportation Institute
         Don L. Ivey PhD.,P.E., Scientific Inquiry, Inc.
         Wanda L Menges, Texas A&M Transportation Institute , w-menges@tamu.edu

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    10-2621 - Criteria for Passing Sight Distance for Roadway Design and Marking
    Session 213
    The research summarized in this paper investigated the need for changes in the passing sight distance (PSD) criteria used for design of two-lane highways and for marking of passing and no-passing zones on two-lane highways. PSD models from the AASHTO Green Book and the MUTCD were first compared with models developed in previous research to determine the most accurate representation of the passing maneuver. It was determined that two models, developed by Glennon and Hassan et al., warranted further consideration. Field studies were then conducted in Missouri and Pennsylvania and recent field data from a study in Texas were also evaluated to validate the assumptions made in the passing models. It was determined that based on current driver behaviors no change in the PSD criteria used for marking passing and no-passing zones was needed. The research found that two-lane highways can be safely designed with any set of PSD criteria equal to or greater than the PSD criteria used in marking passing and no-passing zones, instead of the longer PSD values currently used in design. The use of the current PSD marking criteria in design will provide desirable consistency between PSD design and marking practices.
         Douglas W. Harwood, MRIGlobal, dharwood@mriglobal.org
         David K. Gilmore, MRIGlobal
         Karen  Richard, University of Missouri, Kansas City

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    10-2804 - Roadway Departure and Impact Conditions
    Session 612
    In-depth accident data was collected in order to investigate vehicle impact conditions (i.e., crash severity, impact speed, impact angle, and orientation) for crashes with roadside obstacles and features. Descriptive statistics of these variables are presented, including statistics for the data segregated by highway class, speed limit and access control. Relationships between impact conditions and these segregating factors are explored. Statistical tests were applied to investigate the association between speed and angle, and univariate distributions were fitted for these two variables. It was found that impact speed and impact angle are independent for most highway classes when segregated by highway class and that they have a relatively weak negative correlation. It was also found that both impact speed and angle data for all highway classes follow a normal distribution. Joint impact distributions were then determined using the Bivariate Normal distribution and are presented in this paper. The findings of this study are of significant importance to establish and/or reinforce full-scale vehicle crash testing guidelines, to benefit-cost analysis procedures, and to highway designers who seek for more detailed information on probabilities of impact conditions for different highway classes.
         Francisco Daniel B. Albuquerque, Midwest Roadside Safety Facility, dbenicio@huskers.unl.edu
         Dean L. Sicking, University of Nebraska, Lincoln
         Cody S. Stolle, Midwest Roadside Safety Facility

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    10-3278 - Determining Lengths of Left-Turn Lanes at Signalized Intersections Under Different Left-Turn Signal Schemes
    Session 213
    An analytical procedure for determining the lengths of left-turn lanes at signalized intersections is developed. A large body of literature exists about this subject; however, most of it examines the case when the left-turn and through movements take place during the same signal phase (split phase). Many state DOTs base their guidelines on this case also. This paper develops the general framework for determining the lengths of the left-turn lanes that prevent lane overflow and blockage of the entrance of the left-turn lane by the queued through vehicles. The framework considers many factors: arrival rates and the sequence of left-turn and through vehicles, different signal schemes (the split-phase, permissive-only, protected-only leading, protected-only lagging, and protected-permissive left-turn phases), and intersection capacity. All possible queue patterns (including the leftover from the previous cycle) are identified, and the probabilities of lane blockage and lane overflow are obtained for different combinations of the parameters. The recommended lengths that prevent lane overflow and blockage more than 95% of the cycles are developed. It is found that the lengths that are suggested by the existing guidelines are useful within certain ranges of combinations of left-turn and through volumes. Suggestions are made how to determine the lengths for outside this limited range of combinations. The framework and suggested lengths should be useful for identifying the options of extending lane length or changing the signal scheme in order to manage lane overflow and blockage, and evaluating the adequacy of the current length.
         Shinya  Kikuchi, Virginia Polytechnic Institute and State University, kikuchi@vt.edu
         Nopadon  Kronprasert, Federal Highway Administration

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    10-3391 - Development of Guidelines for Anchor Design for High-Tension Cable Guardrails
    Session 457
    High tension cable guardrail is becoming increasing popular in median and roadside applications due to the promise of reduced deflections upon impact and reduced maintenance. As the performance of these systems is observed in service, there is a growing concern over the end anchorage foundation performance of current systems. Foundations for high tension systems must not only be capable of restraining the impact load of a vehicle but must also must restrain the initial pretension on the cable system as well as temperature induced loads. While it is acceptable for a many roadside safety devices to require foundation repair after impact, this is not acceptable for high tension cable systems as the temperature induced loads can be greater than those loads applied during impact. Foundation deflection can reduce cable tension, increasing deflection of the system during impact and letting the cables sag after impact. The soil conditions in which these foundations are placed vary significantly. This paper considers the potential impact, tension, and temperature loads and develops a set of suggested foundation designs to accommodate a range on in situ soil conditions. These designs will vary significantly in different areas around the nation due to variations in both weather and in situ soil conditions. Deflection during full-scale crash tests may not accurately represent the foundation deflection that will be experienced in the field.
         Ling  Zhu, Midwest Roadside Safety Facility
         John  Rohde, University of Nebraska, Lincoln, jrohde@unl.edu

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    10-3966 - Application of Precast Concrete Barrier Adjacent to Steep Roadside Slope
    Session 277
    When concrete barriers are installed adjacent to drop-offs or steep roadside slopes such as 1.5H:1V, a cast-in-place concrete moment slab is usually attached to the base of the barrier to resist lateral and overturning forces during vehicle impact. Cast-in-place construction can require more time on site to build forms, pour the concrete, and allow for curing. This results in an increase in disruption to traffic and more exposure for construction workers. Furthermore, the installation of a moment slab is very costly and requires an additional construction phase to build the slab. Since the slab is normally under the shoulder and possibly the lanes, the disruption of traffic flow is increased. This paper presents a new application of a precast 42-inch tall single slope concrete barrier for use in front of steep slopes, without requiring a moment slab. The lateral movement of the barrier is restricted by embedding it in soil. This design also reduces the embankment behind the barrier to two feet. The embedded barrier application was successfully evaluated under Manual for Assessing Safety Hardware test level 3 criteria. The permanent deflection of the barrier was 5.5 inches. The use of the embedded concrete barrier in lieu of the typically installed barrier with a moment slab is expected to result in cost savings of approximately $300 per linear foot and reduced time to construct.
         Nauman M. Sheikh P.E., Texas A&M Transportation Institute , nauman@tamu.edu
         Roger P. Bligh, Texas A&M Transportation Institute
         Richard B Albin, Federal Highway Administration
         David K. Olson, Washington State Department of Transportation

     

    Freight Systems

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    10-0559 - Network Competition and Effects of Open Skies in Transatlantic Aviation
    Session 276
    This paper examines how competition in the transatlantic aviation market has evolved over the last decade and evaluates the effects of Open Skies agreements on service levels in specific U.S. and European markets. Our route analysis reveals that, in aggregate since 2000, transatlantic routes have seen an increase in number of competitors. U.S. carriers have gained a disproportionate share of new transatlantic service, leveraging the network effects of flying from their hubs. In our analysis of the effects of Open Skies between European countries and the U.S., we find that the agreements have resulted in both increases and decreases in service levels. Of the 22 European countries with U.S. Open Skies agreements in place by 2007, only seven demonstrated overall increases in service levels while six demonstrated overall reductions. Five countries saw no significant change and the remaining four have yet to receive direct transatlantic service, suggesting that liberalization alone does not oblige service level increases.
         Alex  Cosmas, Booz Allen Hamilton, acosmas@alum.mit.edu
         Peter  Belobaba, Massachusetts Institute of Technology
         William  Swelbar, Massachusetts Institute of Technology

     

    Geology and Earth Materials

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    10-0317 - Energy Efficiency and Rod Length Effect in Standard Penetration Test Hammers
    Session 236
    Please Update this!
         Michael D. Valiquette, North Carolina Department of Transportation
         Brent  Robinson, North Carolina State University, Raleigh, brrobins@ncsu.edu
         Roy H. Borden, North Carolina State University, Raleigh

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    10-0480 - Investigation and Implications of Mechanically Stabilized Earth Wall Corrosion in Nevada
    Session 244
    Nevada Department of Transportation has over 150 mechanically stabilized earth (MSE) walls at 39 locations. Recently, high levels of corrosion were observed due to accidental discovery at two of these locations. The resulting investigations of these walls produced direct measurements of metal corrosion losses and electrochemical properties of the MSE backfill. One MSE wall was replaced with a cast-in-place tie-back wall at great expense. The paper incorporates a statistical analysis that addresses the variability in measured corrosion and electrochemical data to predict corrosion behavior. It is shown that the original MSE backfill approval electrochemical test results are significantly different from those measured in post-construction investigations. A correlation has been developed between two distinctly different soil resistivity test methods, namely the Nevada T235B and AASHTO T-288 methods. Over-prediction made by the Nevada T235B method has proved detrimental to the service lives of MSE walls. The internal stability analyses (using AASHTO 2007 LRFD) of two remaining MSE walls at an intersection were also performed using corrosion loss models developed from the statistical analysis. The findings of the study were subsequently extrapolated to other Nevada MSE walls. Through review of the backfill approval data, suspect Nevada MSE walls have been identified relative to estimated backfill aggressiveness.
         John David Thornley, Hattenburg Dilley & Linnell, jthornley@hdlalaska.com
         Raj  Siddharthan, University of Nevada, Reno
         Barbara  Luke, University of Nevada, Las Vegas
         John Mark Salazar, Nevada Department of Transportation

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    10-0550 - Evaluation of Characterization and Performance Modeling of Cementitiously Stabilized Layers in the Mechanistic-Empirical Pavement Design Guide
    Session 291
    Cementitious stabilization of aggregates and soils is an effective technique to increase the stiffness of the base and subbase layers and modify the structural response of pavement: for instance, cementitious bases can improve the fatigue behavior of asphalt surface layers and subgrade rutting over the short- and long-term. However, the stabilization of soils and aggregates with cement can lead to additional distresses such as shrinkage and fatigue in the stabilized layers. Extensive research has been done to test these materials experimentally and characterize them, however, very little of this research attempts to correlate the mechanical properties of the stabilized layers with their performance. MEPDG provides a promising theoretical framework for the modeling of CSMs performance. However, significant improvements are needed to bring the modeling of semi-rigid pavements in MEPDG to the same level as that of flexible and rigid pavements. Furthermore, the design of pavement systems with stabilized layers is disadvantaged by the fact that the Mechanistic Empirical Pavement Design Guide (MEPDG) does not model cementitiously stabilized materials (CSMs) in the manner similar to those for hot mix asphalt (HMA) or portland cement concrete (PCC) materials; as a result, performance gains from stabilized layers are difficult to assess using the MEPDG. The purpose of this paper is to evaluate the current characterization of CSMs and bring to light issues with their modeling in MEPDG. Addressing of these issues will help the designer to quantify the benefits of stabilization and improve pavement service life.
         Priyam  Saxena, University of Minnesota, saxe0034@umn.edu
         Derek  Tompkins, University of Minnesota
         Lev  Khazanovich, University of Minnesota
         Jose Tadeu Balbo, University of Sao Paulo, Brazil

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    10-1168 - Implementation of Stabilized Blended Calcium Sulfate Materials in Flexible Pavement Design and Construction
    Session 243
    The Blended Calcium Sulfate (BCS), a recycled fluorogypsum waste material, has been used in Louisiana as a pavement base layer for more than a decade. Without further chemical stabilization, the major concern of using raw BCS as a pavement structural layer is its moisture susceptibility. It could cause both short-term construction difficulties and long-term performance problems. In order to improve the moisture susceptibility of BCS, various cementitious agents were used in the laboratory for BCS stabilization. To further verify the efficiency of BCS stabilization schemes obtained from laboratory and assess the field performance for stabilized BCS materials as well as potential cost benefits, three pavement test sections were constructed and tested using the Accelerated Loading Facility (ALF) device. Both laboratory and field test results indicated that a grade 120 granulated ground blast furnace slag (GGBFS) of 10 percent by volume stabilized BCS material possessed a superior performance over raw BCS in terms of water resistance, durability and good long-term performance. Field test results further demonstrated that the GGBFS stabilized BCS base outperformed both a regular crushed stone base and a fly ash stabilized BCS base by a significantly large margin. A life-cycle cost analysis proved that, besides its outstanding laboratory and field performance, using the GGBFS stabilized BCS can provide a substantial long-term savings over regular crushed stone and fly ash stabilized BCS bases in a 30-year pavement design life period.
         Zhong  Wu, Louisiana Transportation Research Center, zhongwu@ltrc.lsu.edu
         Zhongjie  Zhang, Louisiana Department of Transportation and Development
         Mingjiang  Tao, Worcester Polytechnic Institute

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    10-1755 - Mechanistic Laboratory Evaluation and Field Construction of Recycled Concrete Materials for Use in Road Substructures
    Session 243
    Conventional flexible pavement systems require significant volumes of quality aggregates. Unfortunately, most urban centres are faced with depleted aggregate sources. Given recent significant urban infrastructure renewal as well as increased costs associated with landfilling concrete rubble, there is potential to optimize the reclamation and recycling of Portland cement concrete (PCC) and hot mix asphalt concrete (HMAC) rubble through innovative use of these materials in road rehabilitation. The primary objective of this study was to demonstrate the ability to reclaim, process, and recycle stockpiled concrete materials in order to provide improved structural mechanistic-climatic material properties. As part of this objective, it is desirable to meet or exceed the mechanical properties of conventional granular road materials. This research is based on advancements of the “Green Streets” Infrastructure Program in the City of Saskatoon. A second objective of this research was to pilot the field application of reclaimed and recycled asphaltic concrete and PCC rubble in a typical urban road reconstruction application. Recycled HMAC and PCC materials were used in a pilot re construction project of a road exhibiting substructure moisture problems and structural failure. This study showed that recycled HMAC and PCC rubble materials could be processed to achieve mechanistic laboratory properties that exceed those of conventional granular base materials. This study also demonstrated efficient constructability and high end-product structural value of a typical rehabilitated urban road structure test section in the City of Saskatoon utilizing recycled HMAC and PCC rubble.
         Curtis F. Berthelot Ph.D.,P.Eng., University of Saskatchewan, Canada, curtis.berthelot@usask.ca
         Rielle  Haichert, PSITechnologies Inc., Canada
         Diana  Podborochynski, Pavement Scientific International, Canada
         Colin  Wandzura, PSI Technologies, Inc., Canada
         Brian  Taylor P.Eng., Consultant, Canada
         Duane Joel Guenther, City of Saskatoon, Canada

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    10-2215 - Selective Flexible Pavement Rehabilitation Based on Forensic Investigation and Deflection Analysis: Seventeen-Year Case Study in Virginia
    Session 509
    ABSTRACT This paper describes the effectiveness of combining forensic investigation and Falling Weight Deflectometer (FWD) deflection analysis in selecting the most economical best performing rehabilitation remedy for a prematurely failing thin flexible pavement. The project is a four lane divided primary road, about 3 miles long and part of Route 3 in Lancaster County, Fredericksburg District, Virginia. The two west bound lanes were constructed in 1992 with pavement structure consisting of 4.5 inches asphalt concrete on top of 6 inches dense graded aggregate, which rested on a 6 inches soil cement treated layer, on top of the natural subgrade. Within two years of service, it showed white stains at the surface, but no distresses were observed. In 1998 several areas in truck lane failed in fatigue and alligator cracking. The first rehabilitation activity, in 1998, was to mill and replace the asphalt layers, a total of 4.5 inches, without identifying the failure mechanism. This activity proved ineffective and the pavement failed in the same mode but more severely in 1999. Determination of the failure mechanism based on forensic investigation and deflection testing was finally considered, in 2000. The failure mechanism showed that dense plain aggregate which was loaded with fines acted as a weak link between the top and bottom stiff layers and lead to entrapment of moisture (in the absence of pavement edgedrain) and the premature failure due to the truck loading in the truck lane. Based on the forensic investigation and FWD deflection testing, it was decided to remove the asphalt layers and in-place cement stabilize the plain aggregate layer for the truck lane only to provide much stronger pavement by eliminating the weak link. This unique and selective rehabilitation approach resulted in two different treatments one for the truck lane, where most of the heavy loading is applied, and one for the passing lane where light loading is applied. The pavement has performed very well during the last eight years without any signs of distresses. This paper documents the lessons learned from this project, over a span of 17 years.
         Mohamed Khamis Elfino, VIrginia Department of Transportation, mohamed.elfino@vdot.virginia.gov
         Harikrishnan  Nair P.E, Virginia Center for Transportation Innovation and Research

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    10-2278 - Quantifying Effects of Particle Shape and Type and Amount of Fines on Unbound Aggregate Performance Through Controlled Gradation
    Session 651
    Construction of a pavement working platform is often needed on soft, unstable soils to provide sufficient stability and adequate immediate support for equipment mobility and paving operations without developing excessive rutting. Standard specifications may often allow the use of a wide range of aggregate materials for subgrade applications regardless of aggregate properties. The aggregate type and quality are important factors for determining the required treatment/replacement thickness. This paper describes laboratory findings from an ongoing research study at the University of Illinois aimed at evaluating aggregate cover thickness requirements on soft subgrade through characterizing strength and deformation behavior of crushed limestone and dolomite and uncrushed gravel, commonly used in Illinois for subgrade replacement and subbase. The initial laboratory phase consisted of moisture-density, unsoaked CBR, imaging based aggregate shape characterization, and shear strength tests based on a comprehensive experimental test matrix which considered both plastic and non-plastic fines (passing No. 200 sieve or 0.075 mm) blended in the engineered gradations at 4%, 8%, 12%, and 16% target fines contents. From the test results, the most important property at low fines contents (less than 8%) was the aggregate type governed by the angularity, i.e. crushed or uncrushed, and the amount of voids in the aggregate matrix. The uncrushed gravel more quickly filled the voids at lower fine percentages thus making gravel less tolerable to negative effects of increasing fines. When plastic fines (plasticity index or PI of 10 or higher) were included, the amount of fines had a drastic effect on aggregate performance.
         Debakanta  Mishra, University of Illinois, Urbana-Champaign
         Erol  Tutumluer, University of Illinois, Urbana-Champaign, tutumlue@illinois.edu
         Abbas Ahmad Butt, Engineering & Research International, Inc.

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    10-2379 - Variability in Construction of Cement-Treated Base Layers: Material Properties and Contractor Performance
    Session 640
    The primary purposes of this research were to identify construction factors most correlated to specific mechanical properties of cement-treated base (CTB) layers and to determine which construction factors exhibit comparatively high variability within individual construction sections of the two pavement reconstruction projects included in this study. In addition, differences between construction sections tested in this research were evaluated. Researchers collected extensive field and laboratory data, which were analyzed using several statistical techniques. The results of this research suggest that reduced spatial variability is needed in reclaimed asphalt pavement (RAP) content, cement content, and time between mixing and compaction, which were all identified as important predictors of CTB strength in this study. Concerning full-depth reclamation projects, milling plans should be utilized to achieve improved uniformity in RAP content, and inspection protocols for encouraging improved control of cement content during construction should be implemented to ensure high-quality work. Compaction should be performed as soon as possible after mixing to minimize the adverse effects of cement hydration on the ability to achieve maximum dry density in the field. Minimizing variability in construction of CTB layers will ultimately lead to higher quality pavements that more consistently meet design expectations.
         W. Spencer Guthrie, Brigham Young University, guthrie@byu.edu
         Maile A. Rogers, Brigham Young University

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    10-2435 - Optimum Use of Local Material for Roadway Base and Subbase
    Session 230
    Base materials that meet specifications are getting more difficult to get in many regions of the United States. As a result, higher quality materials have to be hauled long distances. This act would significantly increase the costs associated with roadway construction and subsequent maintenance and rehabilitation. Low quality or out-of-specification materials are usually available from local sources. If through appropriate treatment of the materials or/and structural design, the optimum use of local materials can be permitted, the construction can be accelerated and significant monetary benefits can be realized. Under many current specifications, a material can be considered low-quality for a variety of reasons such as inadequate gradation, inadequate plasticity, and inadequate strength. In many cases, the local base supplies miss the specifications by small margins. Since the criteria set in most of current specifications are experienced-based, some of the criteria used to classify a base material may be less significant than others. This paper presents a test protocol for the use of low quality flexible base materials based on the test results of materials from eight local pits in Texas to document how a low-quality material can be used on low-volume roads and still get a quality foundation layer.
         Biraj  Gautam, Marino Engineering Associates, bgautam@meacorporation.com
         Soheil  Nazarian, University of Texas, El Paso
         Deren  Yuan, University of Texas, El Paso

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    10-2620 - Investigation of the Use of Limestone Screenings in Roadway Construction
    Session 230
    Disposal of limestone screenings, or limestone fines, creates problems for many quarry operations. Much of the fines is either stockpiled or deposited back into the quarry pit. A laboratory study and pilot project was conducted to determine if limestone screenings could be stabilized and used as a structural layer in road construction. This project set forth the following objectives: determine from laboratory experiments if limestone screenings could be stabilized and used as a structural layer in road construction and evaluate the effectiveness of stabilized limestone screenings as a structural layer in road construction through performance monitoring. Compaction, unconfined compression, freezing and thawing durability, and wet-dry durability tests were performed to determine if limestone screenings could be stabilized and used as a structural layer in road construction. Falling Weight Deflectometer (FWD) tests were used to compare stiffness differences, and temperature data was used to determine the number of freezing and thawing cycles each test section underwent. Laboratory compaction and unconfined compression test results confirm that limestone screenings can be stabilized for use as a structural layer. Freezing and thawing and wet-dry durability test results show that cement kiln dust (CKD) is not an acceptable stabilizer due to poor durability performance. Class C fly ash (FA) and CKD mixtures were determined to be acceptable. Test section one (30% CKD) most likely failed due to freeze-thaw action. Visual observations show good performance of test section two (15% FA and 15% CKD) and the two control sections with no rutting or pothole formation.
         Tyson  Rupnow, Louisiana Transportation Research Center, Tyson.Rupnow@la.gov
         Vernon Ray Schaefer, Iowa State University
         David J. White, Iowa State University

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    10-2738 - Detecting Voids Under Pavements: Update on Approach of U.S. Department of Defense
    Session 244
    Several accidents involving aircraft punching through airfield pavements prompted the Navy to develop a technology for void detection. Initially, a successful void detection survey was completed at a Naval Air Station where several voids were generated by leakage of large underground drainpipes. Various methods were used such as internal videotaping of the pipes, heavy weight deflectometer (HWD) testing, ground penetrating radar (GPR), and dynamic cone penetrometer (DCP) testing. A state-of-the-art review was also completed to assess all existing technology applicable to void detection under pavements. However, the optimum technology determined (visual inspection, HWD, and DCP) still presented limitations in terms of availability and speed of data acquisition, requiring prioritization of the work. A risk analysis was then completed, establishing work prioritization within each airfield and providing a prioritization of all U.S. Navy and Marine Corps airfield pavements. An Interim Policy and Technical Guidance (IP&TG) was issued on 23 March 2000 to establish the developed void detection methodology. This is now included as an appendix in Department of Defense Unified Facilities Criteria UFC 3-260-03 and routinely applied at all 70 major Navy and Marine Corps airfields. This paper summarizes the methodology used and presents some recent field cases.
         Luis Javier Malvar, U.S. Navy Engineering Service Center, luis.malvar@navy.mil

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    10-3582 - Analysis Method for Drilled Shaft-Stabilized Slopes Using Arching Concept
    Session 236
    The use of drilled shafts to stabilize an unstable slope or to fix a failed slope has gained popularity in highway applications mainly due to the fact that it is a structural fix that does not require additional right of way, as compared to change in slope geometry (adding berms to the toe of the slope) or other methods of stabilization. The main purpose of this paper is to introduce an analysis method for determining the FS of a drilled shaft/slope system and for determining the earth thrust on the drilled shafts for structural design of the drilled shafts. The concept of the analysis is cast in the limiting equilibrium approach via. method of slices, while incorporating the drilled shafts induced arching effects as the soil mass moves down-slope and around the drilled shafts. The mathematical equations based on the limiting equilibrium calculation, together with the load transfer factor for accounting for the drilled shafts induced arching effects, is presented in this paper. The 3-dimensional FEM parametric study using ABAQUS program is used to derive the regression based semi-empirical equations for quantifying the arching effect through the load transfer factor. A UASLOPE computer program is written to incorporate the above mentioned algorithms for applications to real cases. A case study of a fully instrumented and monitored slope stabilization project, ATH-124, in Ohio, is presented. The analysis of the stabilized slope at the ATH-124 project site using FEM and the computer code UA Slope are presented, together with field monitored data. Based on field monitoring data and the comparison between the finite element analysis results and the computer code UA slope for the global factor of safety and shaft force , the suggested analysis and design approach appears to be reasonable.
         Robert  Liang, University of Akron, rliang@uakron.edu
         Wassel  Al Bodour, University of Akron
         Mohammad  Yamin, University of Akron
         Arash  Erfani joorabchi, University of Akron

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    10-3825 - Variability in Resilient Modulus of Reclaimed Asphalt Pavement as Base Layer and Its Impact on Flexible Pavement Performance
    Session 243
    The use of reclaimed asphalt pavement (RAP) as a base layer is gaining popularity, but there are gaps in the literature about the material performance. One problem that has not been well investigated is the variability in the resilient modulus (MR) of RAP as a base layer compared to typical granular material, and the impact of this variability on pavement performance. In addition to the expected variability in MR of the base layer resulting from the use of aggregates that have different qualities, the process of selecting one MR value has its own variability. This paper investigates the effect of three sources of variability in determining the base layer resilient modulus in the laboratory for RAP compared to granular material. The first source that was considered is the variability in the material and sample preparation for the MR testing. The second source of variability is the constitutive model used to predict the resilient modulus. The third source is the state of stress used to predict the base layer modulus. The study compares the variability of MR of RAP to MR of unbound granular materials based on actual testing results. The impact of MR variability for RAP compared to granular material on the flexible pavement distresses is investigated using the Mechanistic-Empirical Pavement Design Guide (MEPDG).
         Mohamed Ibrahim El-Sharkawi Attia, Zagazig University, Egypt
         Magdy  Abdelrahman, North Dakota State University, m.abdelrahman@ndsu.edu

     

    Infrastructure Preservation

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    10-0992 - Fiber-Reinforced Polymer Pile Repair Incorporating Cathodic Protection
    Session 325
    Fiber reinforced polymers (FRP) are increasingly being used for corrosion repair. As barrier elements FRP can only slow down corrosion. Cathodic protection (CP) is the only proven method for stopping electro-chemical corrosion of steel. This paper describes a new method for repairing corrosion damage in which a sacrificial cathodic protection system is incorporated within a FRP repair. The system was implemented in a demonstration project in which corroding piles supporting the Friendship Trail Bridge, Tampa Bay were repaired. The repaired piles were instrumented so that the performance of the CP system could be assessed. Results indicate that the CP system is effective in protecting the reinforcing steel. It also shows that corrosion rates are lower in FRP wrapped piles. This implies longer lives for the sacrificial anodes.
         Rajan  Sen, University of South Florida, sen@eng.usf.edu

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    10-1741 - Failure and Repair of Deck Closure Pour on Interstate 81
    Session 443
    On April 6, 2009 a 3’ x 3’ section of a closure pour in a reinforced concrete deck on Interstate 81 punched through. The deck was cast in 1992 during a deck replacement project in which each lane and shoulder of the deck was replaced while traffic used the adjacent lane. The center closure pour connected the two new deck placements. An examination of the failed section revealed that a total of eighteen #5 rebars were sheared to create the hole in the deck. The epoxy coated rebars had sustained section loss due to corrosion caused by water and chlorides leaking through the construction joint and a transverse crack. Repair consisted of removing an 8-ft wide section of the deck that spanned between the steel beams along each side of the closure pour over the entire length of the bridge, forming the opening, placing MMFX2 reinforcement that spanned between the beams, and placing expansive bridge deck concrete prepared with Type K cement. Four slabs removed from the closure pour area were delivered to the Virginia Tech Structures and Materials Research Laboratory for evaluation. Evaluation methods included chloride contents, concrete resistivities, corrosion potentials and currents and the electrical indication of the resistance of concrete to chloride penetration. This paper presents the results from the evaluation of the closure pour failure and the deck repair.
         Michael M. Sprinkel, Virginia Center for Transportation Innovation and Research, michael.sprinkel@vdot.virginia.gov
         Richard E. Weyers, Virginia Polytechnic Institute and State University

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    10-2214 - Use of Corrosion-Resistant Reinforcement as a Sustainable Technology for Bridge Deck Construction
    Session 325
    As part of the Innovative Bridge Research and Construction Program (IBRCP), this study used the full-scale construction project of the Route 123 Bridge over the Occoquan River in Northern Virginia to identify differences in the installation practices and comprehensive placement costs of epoxy-coated reinforcing steel (ECR) and corrosion-resistant reinforcing steel (CRR), specifically MMFX 2. Two bridge decks were constructed separately with a raised median covering the longitudinal joint between them. The southbound and northbound decks were reinforced with ECR and MMFX 2 respectively. Inclusion of the labor and unanticipated costs directly related to the respective deck reinforcement raised the in-place cost of MMFX 2 from $0.78/lb to $0.87/lb and that of ECR from $0.51/lb to $0.90/lb. Sealing of cracks in the ECR side was determined to be directly related to deck construction, thus these unanticipated costs were included in the $0.90/lb figure. Including the indirect costs of the sealing operations, however, more than quadrupled the final cost of ECR over its initial unit bid price. The final in-place estimated cost of ECR, in the range of $2.34/lb to $2.90/lb, reversed the cost advantage of ECR over MMFX 2 that existed in the planning stage. In the expectation of a future stream of similar maintenance operations and the costs imposed on the public during such operations, the results of this study demonstrate that CRR is the more sustainable choice for deck reinforcement steel and highlights the need to be mindful of hidden costs when comparing reinforcement materials on a cost basis.
         Audrey K. Moruza, Virginia Center for Transportation Innovation and Research, Audrey.Moruza@VDOT.Virginia.gov
         Stephen R. Sharp, Virginia Center for Transportation Innovation and Research

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    10-2736 - Compaction of Noise-Reducing Asphalt Mixtures in the Laboratory
    Session 295
    In recent years, significant amount of research effort has been spent by engineers worldwide to develop alternative asphalt surface mixtures that are quieter, safe, and durable. These mixtures typically have very high air-void contents, placed in thin layers, and compacted in a way different from conventional dense-graded asphalt mixtures. Different compaction methods have been applied to fabricate specimens in laboratory studies. The effect of compaction on mix performance has not been sufficiently studied. This paper investigates the impact of compaction methods on the performance of quiet (porous) asphalt mixtures. Four different compaction methods are included: Marshall impact, Hveem kneading, Superpave gyratory, and rolling wheel compaction. The rolling wheel compaction is selected as a surrogate for field compaction. Specimens of four different porous mixtures with nominal maximum aggregate sizes varying from 4.75 mm to 19.0 mm are compacted by the four methods, and are tested for various performance indices, including permeability, sound absorption, moisture sensitivity, and resistance to raveling and aging. It is found that each compaction method has its own advantages and disadvantages. The effect of compaction methods also varies with the aggregate gradation. Mix performance indices also have different sensitivities to the compaction method.
         Qing  Lu, University of South Florida, qlu@usf.edu
         Sang  Luo, Southeast University, China
         John  Harvey, University of California, Davis

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    10-3951 - Feasibility of Stainless Steel as Bridge Deck Reinforcement Material: Sensitivity of Life-Cycle Evaluation to Key Analysis Variables
    Session 325
    Bridge designers strive to implement cost-effective designs that yield minimal rehabilitation frequency and intensity over the facility life and hence least life-cycle preservation cost to the agency and agencies. As such, the bridge engineering community seeks new materials, configurations, and other design elements to meet this objective. The efficacy of new materials can be influenced by the context under which they are used. This paper discusses the potential of stainless steel as a bridge deck reinforcement material and analyzes the sensitivity of the cost-effectiveness of this material to key input parameters such as interest rate, user cost weight, traffic volume. The superior reinforcement material alternative was determined on the basis of the criteria that include agency cost, user cost, and material service life. Using data from a mid-western state in the United States, this paper carried out sensitivity analysis and showed that using stainless steel as reinforcement material for the bridge deck, under a majority of the analysis scenarios, yields significantly higher initial costs but drastically reduced costs over the bridge life cycle, and thus is more cost-effective over the long term. In harsher environments where bridges are more vulnerable to corrosion, the relative benefits of stainless steel are expected to be even higher.
         Amanda  Cope, Purdue University
         Samuel  Labi, Purdue University, labi@purdue.edu

     

    Investing in Our Transportation Future – BOLD Ideas to Meet BIG Challenges

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    10-3313 - Effect of Frequency of Pavement Condition Data Collection on Performance Prediction
    Session 219
    Monitoring pavement surface conditions over time is essential for pavement management and performance models at the network level. Time series distress data can be used to determine the remaining service life (RSL) at project level, which can then be used for all projects to assess the overall health of the pavement network. Observed field performance is also crucial for calibrating performance prediction models for pavement design purposes. Therefore, highway agencies collect pavement condition data to accomplish both policy and engineering outcomes. However, there exist differences among many agencies between the monitoring frequency used for pavement surface distress (imaging) and that used for the sensor-measured features (roughness, rut depth, and joint faulting). These differences are mainly related to the relative difficulties (cost, resources, and technology) in collecting and processing imaging data. Many agencies collect sensor data more frequently than images. Most of the highway agencies monitor pavement condition at 1-, 2-, or 3-year frequencies. Discrepancies between performance model predictions and observed field performance are conventionally attributed solely to errors in the predicted pavement distresses. In fact, there may also be significant inherent uncertainty in the measured pavement distresses due to spatial variability, sampling, and measurement errors. In addition, the frequency of distress data collection will further add to the uncertainty in performance prediction. This paper explores the effect of pavement condition monitoring frequency on pavement performance prediction. The analyses of the observed performance in several SPS-1 and SPS-2 pavement sections show that condition data collection frequency can significantly affect performance prediction, especially for structural distresses with high variability. This was clearly observed in the case of rigid pavements. Therefore, higher data collection frequency for image-based methods can reduce the associated risk in performance prediction and thus can be more effective for better decision making in the context of pavement management.
         Syed Waqar Haider P.E., Michigan State University, syedwaqa@egr.msu.edu
         Gilbert Y. Baladi, Michigan State University
         Karim  Chatti, Michigan State University

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    10-4064 - New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center
    Session 317
    From September 2008 to April 2009, the New York Metropolitan Transportation Council collaborated with the NYU Wagner Rudin Center on a unique program to offer training courses to professional transportation staff from regional transportation agencies. The Program consisted of 23 courses organized within three distinct modules, Skill Building, Transportation Policy, and Tools and Methods. Tailored for line and mid-level staff as a parallel and complimentary track to the already established NYMTC Executive Education Program developed in the 1990s, 86% of Program participants reported the curriculum to be of strong content and with high relevance to their jobs and professional development. The Program offers a model for MPO and university research center collaboration on continuing professional education for transportation professionals. Connecting agencies through MPOs with university educational resources aligns the training goals to the MPO's regional objectives as well as national transportation education initiatives.
         Lina  Duran, NYU Wagner Rudin Center for Transportation Policy and Management, linaduran@nyu.edu
         Adam  Gromis, NYU Wagner Rudin Center for Transportation Policy and Management
         Kuo-Ann  Chiao, New York Metropolitan Transportation Council

     

    Maintenance

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    10-0741 - Implementation of Structural Control Measures to Mitigate Avalanche Hazard Along Transportation Corridors
    Session 600
    Avalanche hazards along transportation corridors in the United States have traditionally been addressed through the use of forecast their potential and actively controlling them through explosive release while the roadway is closed. This approach reduces the threat of avalanches cascading onto the roadway and thus reduces danger to the traveling public. However, active control methods cannot always be implemented in a timely fashion, can be ineffective, and can have large associated economic impacts. An alternative to active control is passive, structural avalanche defenses. They are “passive” in that they do not require the efforts of winter maintenance personnel during winter storm periods. Structural defense measures include snow sails, snow supporting structures, and snow sheds. Despite their extensive use in Europe and their potential for effectively reducing avalanche hazards, there are very few examples to be found in the United States. The potential for negative impacts to the visual attributes of the landscape has been a significant reason for their lack of domestic use. This paper discusses several types of structural defense measures, criteria for their selection at a given site, and their relative effectiveness. Passive structural defense measures designed for implementation at the 151 Avalanche on US Route 89/191near Jackson, Wyoming are described. Details are given on important collaborations between landscape architects and engineers that led to successfully addressing National Environmental Policy Act (NEPA) requirements for retention of visual attributes at the 151 Avalanche site in the presence of snow support structures deployed for the purpose of avalanche hazard reduction.
         Joshua  Hewes, Northern Arizona University, Joshua.Hewes@nau.edu
         Rand  Decker, Northern Arizona University
         Scott  Merry, Kleinfelder, Inc.
         Jamie M Yount, Wyoming Department of Transportation

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    10-0992 - Fiber-Reinforced Polymer Pile Repair Incorporating Cathodic Protection
    Session 325
    Fiber reinforced polymers (FRP) are increasingly being used for corrosion repair. As barrier elements FRP can only slow down corrosion. Cathodic protection (CP) is the only proven method for stopping electro-chemical corrosion of steel. This paper describes a new method for repairing corrosion damage in which a sacrificial cathodic protection system is incorporated within a FRP repair. The system was implemented in a demonstration project in which corroding piles supporting the Friendship Trail Bridge, Tampa Bay were repaired. The repaired piles were instrumented so that the performance of the CP system could be assessed. Results indicate that the CP system is effective in protecting the reinforcing steel. It also shows that corrosion rates are lower in FRP wrapped piles. This implies longer lives for the sacrificial anodes.
         Rajan  Sen, University of South Florida, sen@eng.usf.edu

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    10-1741 - Failure and Repair of Deck Closure Pour on Interstate 81
    Session 443
    On April 6, 2009 a 3’ x 3’ section of a closure pour in a reinforced concrete deck on Interstate 81 punched through. The deck was cast in 1992 during a deck replacement project in which each lane and shoulder of the deck was replaced while traffic used the adjacent lane. The center closure pour connected the two new deck placements. An examination of the failed section revealed that a total of eighteen #5 rebars were sheared to create the hole in the deck. The epoxy coated rebars had sustained section loss due to corrosion caused by water and chlorides leaking through the construction joint and a transverse crack. Repair consisted of removing an 8-ft wide section of the deck that spanned between the steel beams along each side of the closure pour over the entire length of the bridge, forming the opening, placing MMFX2 reinforcement that spanned between the beams, and placing expansive bridge deck concrete prepared with Type K cement. Four slabs removed from the closure pour area were delivered to the Virginia Tech Structures and Materials Research Laboratory for evaluation. Evaluation methods included chloride contents, concrete resistivities, corrosion potentials and currents and the electrical indication of the resistance of concrete to chloride penetration. This paper presents the results from the evaluation of the closure pour failure and the deck repair.
         Michael M. Sprinkel, Virginia Center for Transportation Innovation and Research, michael.sprinkel@vdot.virginia.gov
         Richard E. Weyers, Virginia Polytechnic Institute and State University

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    10-2214 - Use of Corrosion-Resistant Reinforcement as a Sustainable Technology for Bridge Deck Construction
    Session 325
    As part of the Innovative Bridge Research and Construction Program (IBRCP), this study used the full-scale construction project of the Route 123 Bridge over the Occoquan River in Northern Virginia to identify differences in the installation practices and comprehensive placement costs of epoxy-coated reinforcing steel (ECR) and corrosion-resistant reinforcing steel (CRR), specifically MMFX 2. Two bridge decks were constructed separately with a raised median covering the longitudinal joint between them. The southbound and northbound decks were reinforced with ECR and MMFX 2 respectively. Inclusion of the labor and unanticipated costs directly related to the respective deck reinforcement raised the in-place cost of MMFX 2 from $0.78/lb to $0.87/lb and that of ECR from $0.51/lb to $0.90/lb. Sealing of cracks in the ECR side was determined to be directly related to deck construction, thus these unanticipated costs were included in the $0.90/lb figure. Including the indirect costs of the sealing operations, however, more than quadrupled the final cost of ECR over its initial unit bid price. The final in-place estimated cost of ECR, in the range of $2.34/lb to $2.90/lb, reversed the cost advantage of ECR over MMFX 2 that existed in the planning stage. In the expectation of a future stream of similar maintenance operations and the costs imposed on the public during such operations, the results of this study demonstrate that CRR is the more sustainable choice for deck reinforcement steel and highlights the need to be mindful of hidden costs when comparing reinforcement materials on a cost basis.
         Audrey K. Moruza, Virginia Center for Transportation Innovation and Research, Audrey.Moruza@VDOT.Virginia.gov
         Stephen R. Sharp, Virginia Center for Transportation Innovation and Research

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    10-2736 - Compaction of Noise-Reducing Asphalt Mixtures in the Laboratory
    Session 295
    In recent years, significant amount of research effort has been spent by engineers worldwide to develop alternative asphalt surface mixtures that are quieter, safe, and durable. These mixtures typically have very high air-void contents, placed in thin layers, and compacted in a way different from conventional dense-graded asphalt mixtures. Different compaction methods have been applied to fabricate specimens in laboratory studies. The effect of compaction on mix performance has not been sufficiently studied. This paper investigates the impact of compaction methods on the performance of quiet (porous) asphalt mixtures. Four different compaction methods are included: Marshall impact, Hveem kneading, Superpave gyratory, and rolling wheel compaction. The rolling wheel compaction is selected as a surrogate for field compaction. Specimens of four different porous mixtures with nominal maximum aggregate sizes varying from 4.75 mm to 19.0 mm are compacted by the four methods, and are tested for various performance indices, including permeability, sound absorption, moisture sensitivity, and resistance to raveling and aging. It is found that each compaction method has its own advantages and disadvantages. The effect of compaction methods also varies with the aggregate gradation. Mix performance indices also have different sensitivities to the compaction method.
         Qing  Lu, University of South Florida, qlu@usf.edu
         Sang  Luo, Southeast University, China
         John  Harvey, University of California, Davis

    Back to Top

    10-3951 - Feasibility of Stainless Steel as Bridge Deck Reinforcement Material: Sensitivity of Life-Cycle Evaluation to Key Analysis Variables
    Session 325
    Bridge designers strive to implement cost-effective designs that yield minimal rehabilitation frequency and intensity over the facility life and hence least life-cycle preservation cost to the agency and agencies. As such, the bridge engineering community seeks new materials, configurations, and other design elements to meet this objective. The efficacy of new materials can be influenced by the context under which they are used. This paper discusses the potential of stainless steel as a bridge deck reinforcement material and analyzes the sensitivity of the cost-effectiveness of this material to key input parameters such as interest rate, user cost weight, traffic volume. The superior reinforcement material alternative was determined on the basis of the criteria that include agency cost, user cost, and material service life. Using data from a mid-western state in the United States, this paper carried out sensitivity analysis and showed that using stainless steel as reinforcement material for the bridge deck, under a majority of the analysis scenarios, yields significantly higher initial costs but drastically reduced costs over the bridge life cycle, and thus is more cost-effective over the long term. In harsher environments where bridges are more vulnerable to corrosion, the relative benefits of stainless steel are expected to be even higher.
         Amanda  Cope, Purdue University
         Samuel  Labi, Purdue University, labi@purdue.edu

     

    Management and Leadership

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    10-0471 - Agency-Initiated Bus Noise Reduction for Los Angeles Metro Orange Line
    Session 523
    This paper presents noise control efforts of the Los Angeles County Metro Orange Line, one of the first bus rapid transit (BRT) systems in the U.S. through residential areas. The Orange Line is a 14-mile (22.5 km) dedicated BRT corridor in the San Fernando Valley in Los Angeles County that utilizes 60-foot (18.3 m), articulated vehicles powered by compressed natural gas engines. Noise control efforts included noise mitigation design features, establishing noise emission values of the buses, modeling of the operational noise to determine location where residual impacts occur, establishing background noise levels, monitoring operational noise levels, mitigation of residual noise impacts, and retrofitting the fleet with new mufflers. The paper discusses the results of an agencies commitment to resolving community environmental noise issues and provides guidance regarding noise modeling and noise specification of city buses.
         Ramon  Nugent, Acentech Inc., rnugent@acentech.com
         McDuffee  Mathew, Acentech Inc.
         Carl Peter Ripaldi, Los Angeles County Metropolitan Transportation Authority
         Michael  Chang, Los Angeles County Metropolitan Transportation Authority

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    10-4064 - New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center
    Session 317
    From September 2008 to April 2009, the New York Metropolitan Transportation Council collaborated with the NYU Wagner Rudin Center on a unique program to offer training courses to professional transportation staff from regional transportation agencies. The Program consisted of 23 courses organized within three distinct modules, Skill Building, Transportation Policy, and Tools and Methods. Tailored for line and mid-level staff as a parallel and complimentary track to the already established NYMTC Executive Education Program developed in the 1990s, 86% of Program participants reported the curriculum to be of strong content and with high relevance to their jobs and professional development. The Program offers a model for MPO and university research center collaboration on continuing professional education for transportation professionals. Connecting agencies through MPOs with university educational resources aligns the training goals to the MPO's regional objectives as well as national transportation education initiatives.
         Lina  Duran, NYU Wagner Rudin Center for Transportation Policy and Management, linaduran@nyu.edu
         Adam  Gromis, NYU Wagner Rudin Center for Transportation Policy and Management
         Kuo-Ann  Chiao, New York Metropolitan Transportation Council

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    10-4092 - Mitigating Excessive Idling of Transit Buses
    Session 523
    In recent years, much media attention has been paid to research developments related to three types of diesel vehicles: School buses, long-haul trucks and transit buses. Transit bus emissions studies get attention often because the public wants to know if transit agencies are spending public dollars efficiently and with concern for public health. The public health and environmental effects of transit bus idling and strategies to mitigate idling practices need to be understood. Most transit bus idling is considered “non-discretionary,” occurring while a bus is stuck in traffic or making a stop along its route. There are, however, some scenarios in which transit buses idle unnecessarily, and despite the fact that many solutions exist to limit idling from these buses, these solutions have not garnered much interest from transit agencies, researchers or lawmakers. This paper will review the causes and effects of transit bus idling, and will examine the potential costs and benefits of employing idling-reduction technologies and policies on the bus fleet of a large metropolitan transit agency in the Midwest to limit fuel consumption and emissions. The paper is organized as follows: Economic, environmental and health effects of diesel emissions are discussed in the background section, as well as current anti-idling public policy. The research methodology is described, and causes of excessive bus idling at the Chicago Transit Authority are discussed as well as potential solutions. Idling-reduction technologies are examined to determine which provides the greatest economic and environmental benefit for the lowest cost. The conclusion presents specific recommendations for the Chicago Transit Authority.
         Emily  Ziring, University of Illinois, Chicago
         P. S. Sriraj, University of Illinois, Chicago, sriraj@uic.edu

     

    Operations

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    10-0741 - Implementation of Structural Control Measures to Mitigate Avalanche Hazard Along Transportation Corridors
    Session 600
    Avalanche hazards along transportation corridors in the United States have traditionally been addressed through the use of forecast their potential and actively controlling them through explosive release while the roadway is closed. This approach reduces the threat of avalanches cascading onto the roadway and thus reduces danger to the traveling public. However, active control methods cannot always be implemented in a timely fashion, can be ineffective, and can have large associated economic impacts. An alternative to active control is passive, structural avalanche defenses. They are “passive” in that they do not require the efforts of winter maintenance personnel during winter storm periods. Structural defense measures include snow sails, snow supporting structures, and snow sheds. Despite their extensive use in Europe and their potential for effectively reducing avalanche hazards, there are very few examples to be found in the United States. The potential for negative impacts to the visual attributes of the landscape has been a significant reason for their lack of domestic use. This paper discusses several types of structural defense measures, criteria for their selection at a given site, and their relative effectiveness. Passive structural defense measures designed for implementation at the 151 Avalanche on US Route 89/191near Jackson, Wyoming are described. Details are given on important collaborations between landscape architects and engineers that led to successfully addressing National Environmental Policy Act (NEPA) requirements for retention of visual attributes at the 151 Avalanche site in the presence of snow support structures deployed for the purpose of avalanche hazard reduction.
         Joshua  Hewes, Northern Arizona University, Joshua.Hewes@nau.edu
         Rand  Decker, Northern Arizona University
         Scott  Merry, Kleinfelder, Inc.
         Jamie M Yount, Wyoming Department of Transportation

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    10-1768 - Improving Road Weather Hazard Products with Vehicle Probe Data: Vehicle Data Translator Quality-Checking Procedures
    Session 211
    One of the goals of the Research and Innovative Technology Administration’s IntelliDriveSM initiative is for the public and private organizations that collect, process, and generate weather products to utilize vehicle sensor data to improve weather and road condition hazard products. It is possible that some users will not be able to — or not want to — contend with the complexities associated with vehicle data, such as data quality, representativeness, and format. With funding and support from the U.S. Department of Transportation’s (USDOT) Research and Innovative Technology Administration (RITA) IntelliDriveSM initiative and direction from the Federal Highway Administration’s (FHWA) Road Weather Management Program, the National Center for Atmospheric Research (NCAR) is conducting research to develop a Vehicle Data Translator (VDT) to address these vehicle-based data challenges. This paper first describes the VDT quality-check (QCh) concept and then examines QCh pass rates for temperature and pressure data collected from 11 specially-equipped vehicles operating in the Detroit Testbed in April 2009. Results show that temperature pass rates are higher than pressure. Additionally, pass rates are affected by vehicle type, vehicle speed, ambient temperature, and precipitation occurrence for both temperature and pressure.
         Sheldon  Drobot, National Center for Atmospheric Research, drobot@ucar.edu
         Michael Benjamin Chapman, National Center for Atmospheric Research
         Elena  Schuler, National Center for Atmospheric Research
         Gerry  Wiener, National Center for Atmospheric Research
         William Paul Mahoney III, National Center for Atmospheric Research
         Paul A. Pisano, Federal Highway Administration
         Ben  McKeever, Research and Innovative Technology Administration

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    10-2736 - Compaction of Noise-Reducing Asphalt Mixtures in the Laboratory
    Session 295
    In recent years, significant amount of research effort has been spent by engineers worldwide to develop alternative asphalt surface mixtures that are quieter, safe, and durable. These mixtures typically have very high air-void contents, placed in thin layers, and compacted in a way different from conventional dense-graded asphalt mixtures. Different compaction methods have been applied to fabricate specimens in laboratory studies. The effect of compaction on mix performance has not been sufficiently studied. This paper investigates the impact of compaction methods on the performance of quiet (porous) asphalt mixtures. Four different compaction methods are included: Marshall impact, Hveem kneading, Superpave gyratory, and rolling wheel compaction. The rolling wheel compaction is selected as a surrogate for field compaction. Specimens of four different porous mixtures with nominal maximum aggregate sizes varying from 4.75 mm to 19.0 mm are compacted by the four methods, and are tested for various performance indices, including permeability, sound absorption, moisture sensitivity, and resistance to raveling and aging. It is found that each compaction method has its own advantages and disadvantages. The effect of compaction methods also varies with the aggregate gradation. Mix performance indices also have different sensitivities to the compaction method.
         Qing  Lu, University of South Florida, qlu@usf.edu
         Sang  Luo, Southeast University, China
         John  Harvey, University of California, Davis

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    10-3060 - Diagnosing Road Weather Conditions with Vehicle Probe Data: Results from Detroit IntelliDrive Field Study
    Session 211
    Over the past two years, the USDOT/Research and Innovative Technology Administration funded an IntelliDriveSM vehicle probe data collection testbed in the Northwest Detroit area (the Detroit Testbed). The purpose of the testbed was to provide the infrastructure for both public and private organizations to collect, process, and generate a robust observation dataset for multiple purposes (e.g., crash avoidance, automated toll services, weather diagnostics). During April 2009, a weather specific field study was performed over an 11-day period. The resulting dataset was processed by a Vehicle Data Translator (VDT), which parsed, quality controlled, and combined these data (with ancillary weather data) in the generation of road-weather specific algorithms. This paper briefly describes the VDT concept and then examines the accuracy of the quality-controlled temperature and pressure data (for several different stratifications) collected from 11 specially-equipped vehicles operated during the study time period. Results show that the vehicles accurately measure the temperature (compared with a nearby fixed weather station; KDTW), but are not as accurate at measuring the barometric pressure. In addition, stratification by speed, vehicle type, time of day, and occurrence of precipitation do not affect the accuracy of the temperature and barometric pressure measurements
         Michael Benjamin Chapman, National Center for Atmospheric Research, mchapman@ucar.edu

     

    Pavement Management

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    10-0164 - Expert System for Design of Low-Volume Roads over Expansive Soils
    Session 511
    This paper summarizes the development of an expert system to assist pavement engineers in designing more realistic and practical low-volume roads in clayey areas. This expert system combines numerical and engineering analyses with heuristic information about the site to recommend optimal design, remediation and construction alternatives. Common distress types are considered. In particular, numerical analysis is incorporated to predict the potential for longitudinal cracking of the section, which was reported by a survey throughout Texas to be the most prevailing distress. After assessing the structural capacitity, remediation methods are proposed to address the problem of pre-mature failure of low-volume roads on high-PI clays. Cost-benefit analyses are added to compare cost-effectiveness of alternative recommended strategies. Finally a case study is presented to illustrate the use of the software. Based on preliminary study of typical low-volume roads in Texas built over expansive subsoils, thicker and stronger pavement layers do not guarantee better performance. Instead, addressing the environmental factors on changes in subgrade properties play a bigger role in serviceability and performance.
         Yaqi  Wanyan, Texas Southern University, wanyany@tsu.edu
         Imad N. Abdallah, University of Texas, El Paso
         Soheil  Nazarian, University of Texas, El Paso
         Anand J. Puppala, University of Texas, Arlington

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    10-0434 - Influence of Reclaimed Asphalt Pavement on Surface Friction
    Session 505
    Reclaimed asphalt pavement (RAP) is currently a widely used material for the construction of asphalt pavements. However, in regions deficient in non-polishing aggregates, RAP is not commonly allowed in mainline surface courses for high volume roadways because of friction performance concerns. The goal of the present study was to determine the maximum amount of RAP that can be blended with high friction aggregates and used in surface mixes without significantly impacting their frictional properties. The initial part of the study described here included a comparison of RAPs collected from six different sources (mix plant stockpiles) in Indiana. It was shown that the field-collected RAP’s exhibited fairly consistent properties in terms of their gradations and binder contents. In the second part of the study, low friction aggregate (limestone) was used to produce a “worst case scenario” RAP, for evaluation of its influence on frictional characteristics of two types of hot mix asphalt mixtures: (a) dense graded asphalt (DGA), and (b) stone matrix asphalt (SMA). The DGA and SMA mixtures were produced with various amounts of this “laboratory-produced” RAP. The RAP was blended with two types of highly friction resistant aggregates: steel slag and air cooled blast furnace slag. Overall, the results suggest that for the materials and mixtures studied the maximum amount (threshold level) of RAP, which can be used in surface mixes without detrimental effect on their frictional properties, was about 30%. That addition level did not seem to depend on the type of aggregate present in RAP.
         Karol J. Kowalski, Warsaw University of Technology, Poland, k.kowalski@il.pw.edu.pl
         Rebecca S. McDaniel, Purdue University
         Jan  Olek, Purdue University

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    10-0480 - Investigation and Implications of Mechanically Stabilized Earth Wall Corrosion in Nevada
    Session 244
    Nevada Department of Transportation has over 150 mechanically stabilized earth (MSE) walls at 39 locations. Recently, high levels of corrosion were observed due to accidental discovery at two of these locations. The resulting investigations of these walls produced direct measurements of metal corrosion losses and electrochemical properties of the MSE backfill. One MSE wall was replaced with a cast-in-place tie-back wall at great expense. The paper incorporates a statistical analysis that addresses the variability in measured corrosion and electrochemical data to predict corrosion behavior. It is shown that the original MSE backfill approval electrochemical test results are significantly different from those measured in post-construction investigations. A correlation has been developed between two distinctly different soil resistivity test methods, namely the Nevada T235B and AASHTO T-288 methods. Over-prediction made by the Nevada T235B method has proved detrimental to the service lives of MSE walls. The internal stability analyses (using AASHTO 2007 LRFD) of two remaining MSE walls at an intersection were also performed using corrosion loss models developed from the statistical analysis. The findings of the study were subsequently extrapolated to other Nevada MSE walls. Through review of the backfill approval data, suspect Nevada MSE walls have been identified relative to estimated backfill aggressiveness.
         John David Thornley, Hattenburg Dilley & Linnell, jthornley@hdlalaska.com
         Raj  Siddharthan, University of Nevada, Reno
         Barbara  Luke, University of Nevada, Las Vegas
         John Mark Salazar, Nevada Department of Transportation

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    10-0550 - Evaluation of Characterization and Performance Modeling of Cementitiously Stabilized Layers in the Mechanistic-Empirical Pavement Design Guide
    Session 291
    Cementitious stabilization of aggregates and soils is an effective technique to increase the stiffness of the base and subbase layers and modify the structural response of pavement: for instance, cementitious bases can improve the fatigue behavior of asphalt surface layers and subgrade rutting over the short- and long-term. However, the stabilization of soils and aggregates with cement can lead to additional distresses such as shrinkage and fatigue in the stabilized layers. Extensive research has been done to test these materials experimentally and characterize them, however, very little of this research attempts to correlate the mechanical properties of the stabilized layers with their performance. MEPDG provides a promising theoretical framework for the modeling of CSMs performance. However, significant improvements are needed to bring the modeling of semi-rigid pavements in MEPDG to the same level as that of flexible and rigid pavements. Furthermore, the design of pavement systems with stabilized layers is disadvantaged by the fact that the Mechanistic Empirical Pavement Design Guide (MEPDG) does not model cementitiously stabilized materials (CSMs) in the manner similar to those for hot mix asphalt (HMA) or portland cement concrete (PCC) materials; as a result, performance gains from stabilized layers are difficult to assess using the MEPDG. The purpose of this paper is to evaluate the current characterization of CSMs and bring to light issues with their modeling in MEPDG. Addressing of these issues will help the designer to quantify the benefits of stabilization and improve pavement service life.
         Priyam  Saxena, University of Minnesota, saxe0034@umn.edu
         Derek  Tompkins, University of Minnesota
         Lev  Khazanovich, University of Minnesota
         Jose Tadeu Balbo, University of Sao Paulo, Brazil

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    10-0710 - Local Calibration of Mechanistic-Empirical Pavement Design Guide Rutting Model for Minnesota Road Research Project Test Sections
    Session 505
    The AASHTO interim Mechanistic-Empirical Pavement Design Guide (MEPDG) was recently introduced in the United States. Many State agencies have conducted validation and local calibration of the MEPDG performance prediction models. In this study, time history rutting performance data for pavement sections at the Minnesota Department of Transportation (Mn/DOT) full-scale pavement research facility (MnROAD) have been used for an evaluation and local calibration of the MEPDG rutting model. A detailed comparison of the predicted total rutting, asphalt layer rutting, and measured rutting is presented. The paper discusses why a conventional MEPDG model calibration was not found to feasible and recommends a modification of the rutting model. It was found that the locally calibrated model greatly improved the MEPDG rutting prediction for various pavement designs in MnROAD conditions.
         Kyle  Hoegh, University of Minnesota, hoeg0021@umn.edu
         Lev  Khazanovich, University of Minnesota
         Maureen  Jensen, Minnesota Department of Transportation

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    10-0794 - Bonded Whitetopping Overlay Design Considerations for Prevention of Reflection Cracking, Joint Sealing, and the Use of Dowel Bars
    Session 214
    Thousands of bonded Portland cement concrete (PCC) overlays of hot mix asphalt (HMA) pavements are being constructed all over the United States and around the world. Increasing interest in this rehabilitation method has lead to a need to further define the most common forms of distresses, quantify the extent of influence of design parameters on performance and to develop rational design guidelines. The main focus of this study is to evaluate the performance of in-service pavements to establish criteria on when reflection cracks might develop. It is revealed that reflection cracking is dictated by the thickness of PCC overlay and HMA layer, panel size, climatic conditions, and by the accumulated vehicle loads. It has been found that when the stiffness of the PCC overlay relative and HMA layer (defined during the coldest month of the year) falls below the critical value 1, then reflection cracking develops. The rate of development is a function of the load-related stress in the overlay. The performance analysis of the in-service pavements also verified the benefits of joint sealing and the use of small diameter dowel bars for high volume roadway applications.
         Julie M. Vandenbossche, University of Pittsburgh, jmv7@pitt.edu

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    10-1086 - Relative Effectiveness of Grooves in Tire and Pavement in Reducing Vehicle Hydroplaning Risk
    Session 678
    Grooving of pavement surface and tire tread has been accepted as a good practice to enhance road travel safety against wet-weather skidding and hydroplaning. There have been many guidelines on their use in practice, basically derived from findings of experimental studies and field experience. There is a lack of theoretical studies to provide insights into the factors and mechanisms involved. This paper presents an attempt to apply a theoretically derived analytical simulation model to study the relative effectiveness of pavement grooving and tire grooving in reducing vehicle hydroplaning risk. Three basic grooving configurations were considered: ungrooved, longitudinally grooved, and transversely grooved. Altogether there are nine different combinations of grooving configurations. To form a common basis for comparison, constant values of groove width, groove spacing and water film thickness were considered in the computation of hydroplaning speeds for different groove depths. Overall, the analysis shows that transverse grooves perform better than longitudinal grooves in raising hydroplaning speed (i.e. reducing hydroplaning risk), and that pavement grooving is a more effective measure than grooving tire tread in reducing hydroplaning risk. Further detailed examinations of the results were conducted to study the practical implications of the findings. It was found that for longitudinal grooving which is commonly adopted in highways, pavement and tire grooving are of equal importance in their contributions towards reducing hydroplaning risk. In the case of runways where transverse grooving is the standard practice, pavement grooving is the dominating component in guarding against hydroplaning.
         Tien Fang  Fwa, National University of Singapore, ceefwatf@nus.edu.sg
         Kumar  Anupam, TU Delft, Netherlands
         Ghim Ping  Ong, National University of Singapore

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    10-1542 - Exploring Sustainable Pavement Rehabilitation: Cold In-place Recycling with Expanded Asphalt Mix
    Session 459
    Pavement rehabilitation is a critical component to maintain pavement serviceability and performance. Riding surface of the pavement deteriorates over time due to environment, load, material and construction related distresses. In a society where funding and natural resources are scarce, sustainable pavement rehabilitations become the emerging trend to maximize pavement performance using the available funds. Cold In-Place Recycling with Expanded Asphalt Mix (CIREAM) is a very sustainable pavement rehabilitation technique currently available in the industry. CIREAM is an in-place recycling technique that utilizes expanded asphalt (also known as foamed asphalt) without pulverizing the existing pavement. It works similar to cold in-place recycling (CIR) in terms of milling existing pavement when CIR typically uses emulsified asphalt to provide additional adhesion to the recycled aggregates. Foamed asphalt and emulsified asphalt both use water as an additive to cause asphalt cement to foam. The potential benefit of CIREAM includes savings in asphalt cement, in situ recycling of aggregates, significant money and time savings in transportation cost and disposal cost, and low curing time after rehabilitation for traffic. The paper explores planning, design, construction, quality assurance, and environmental aspect of CIREAM in a qualitative manner. The planning for CIREAM involves identifying potential pavement distresses that can be treated with CIREAM. The CIREAM rehabilitation design considers CIREAM mix design, mill depth design, and overlay design. This paper addresses critical items for construction to ensure a good quality results. Quality assurance tests are also explored to understand the acceptance criteria for CIREAM rehabilitation. Lastly, the environmental evaluation for CIREAM through PaLATE analysis is conducted to demonstrate the environmental impacts of CIREAM compared to conventional mill and overlay. This analysis illustrates the energy use, emissions, and carbon footprint associated with CIREAM rehabilitation.
         Peter  Chan, University of Waterloo, Canada, pcpchan@engmail.uwaterloo.ca
         Susan Louise Tighe, University of Waterloo, Canada
         Susanne  Chan, Ontario Ministry of Transportation, Canada

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    10-1669 - Longitudinal Joint Data Collection Efforts in Virginia Between 2005 and 2009
    Session 511
    Premature deterioration of asphalt concrete at longitudinal joints has been a problem for many transportation agencies over the years. The primary cause for this deterioration is the lack of in-place density. To address this issue, the Virginia Department of Transportation (VDOT) and the Virginia Asphalt Association (VAA) formed an alliance to seek a solution to the problem. Instead of developing a new specification regarding longitudinal joint density and potentially increasing construction costs, the alliance developed a communication and training plan focused on proper joint compaction. This plan included a joint construction memorandum and a field training program. During the implementation year (2005), data collection revealed improved density values at the joints. However, in subsequent years (2006 and 2007) the joint densities began to decline. Therefore, VDOT and VAA placed an emphasis on adherence to proper joint construction during the 2009 paving season. Results collected through July 2009 indicate a significant improvement in joint densities. A substantial improvement was noted in the SM-12.5 surface mixes. Average differences of less than 2% between mat and joint densities for the 12.5 mm mixes were obtained. Statistical results from analysis of variance (ANOVA) and F tests also confirmed this trend
         Alexander Kwasi Appea PhD. P.E, Virginia Department of Transportation, Alexander.Appea@VDOT.Virginia.gov
         Trenton  Clark, Virginia Asphalt Association

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    10-1724 - Comparative Performance of Conventional Cold In-place Recycling to Cold In-place Recycling with Expanded Asphalt: Ontario’s Experience
    Session 459
    The Ministry of Transportation Ontario (MTO) constructed its first 5-km trial section of Cold In-Place Recycled Expanded Asphalt Mix (CIREAM) on Highway 7, east of Perth in July 2003, adjacent to 7-km of Cold in-place recycling (CIR) mix. Conventional cold in-place recycling (CIR) is an established pavement rehabilitation method that processes an existing hot mix asphalt (HMA) pavement, sizes it, mixes in additional emulsified asphalt, and lays it back down without off-site hauling and processing. A recent development in CIR technology termed Cold In-Place Recycled Expanded Asphalt Mix (CIREAM) is the use of expanded (foamed) asphalt, rather than emulsified asphalt to bind the mix. Both technologies are considered to be a sustainable pavement rehabilitation that generates less greenhouse gas emission. Both CIR and CIREAM pavement sections were uniform in appearance and performed similarly under traffic. The sections now have 5 years of performance data and the visual distress survey indicated the pavement is performing very well. Automatic Road Analyzer (ARAN) was carried out on an annual basis to evaluate pavement roughness and rutting. Falling Weight Deflectometer (FWD) testing was also carried out annually to compare the strength of CIR and CIREAM. Results of an ANOVA analysis of the ARAN and FWD data show the two sections are performing statistically the same. Summary of the resilient modulus and indirect tensile strength of the two mixes are presented. The five year performance data for CIREAM indicates that the technology is a promising alternative to conventional CIR. MTO will continue to monitor the long-term performance of this innovative rehabilitation technology.
         Susanne  Chan, Ontario Ministry of Transportation, Canada, Susanne.chan@ontario.ca
         Becca  Lane P.Eng., Ontario Ministry of Transportation, Canada
         Thomas J. Kazmierowski, Golder Associates Ltd., Canada
         Chris  Raymond, Ontario Ministry of Transportation, Canada
         Warren  Lee, Ontario Ministry of Transportation, Canada

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    10-1739 - Full-Scale Field Testing for Injected Foam Stabilization of Portland Cement Concrete Repairs
    Session 214
    A series of foam-injected repairs were performed on a portland cement concrete (PCC) test section at the U.S. Army Engineer Research and Development Center. Repairs consisted of uncompacted backfill overlaid by a 9-in. rapid-setting cementitious cap. A series of injection tubes were inserted through the cap into the backfill, and a two-component rigid polyurethane foam was injected into the underlying backfill. The test matrix compared the performance of three different repairs using various volumes of injected foam. An additional control repair was constructed without injected foam. Three hours after cap construction, repairs underwent simulated aircraft traffic using an F-15E load cart. The performance of the four repairs was measured in terms of passes to failure. The results of traffic testing were used to quantify the benefits of foam-injection technology for rapid repair of PCC pavements. Results showed that injection of excessive foam was detrimental to pavement performance, inducing cracking prior to traffic application. However, repairs using moderate amounts of foam sustained the required traffic levels, defined by the research sponsor, of 200 passes. The performances of foam-injected repairs were also compared with poured foam and traditional backfill repairs, each capped with rapid-setting materials. Comparisons were also made in terms of cost as well as total repair time.
         Lucy Phillips Priddy, U.S. Army Engineer Research and Development Center, lucy.p.priddy@usace.army.mil
         Sarah  Jersey, U.S. Army Engineer Research and Development Center
         Cody  Reese, Naval Facilities Engineering Command's Engineering Service Center

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    10-1938 - CalME: A Mechanistic-Empirical Program to Analyze and Design Flexible Pavement Rehabilitation
    Session 303
    A computer program, known as CalME, has been developed for analysis and design of new flexible pavements and rehabilitation of existing pavements. The paper describes the overlay design procedure and the calibration of the models for reflection cracking and permanent deformation through Heavy Vehicle Simulator (HVS) tests. To simplify the input process the program includes databases for traffic loading, climatic conditions and standard materials. A companion program was developed for backcalculation of layer moduli, and the results may be automatically imported into the CalME database. The program incorporates the existing, empirical Caltrans design methods as well as an incremental-recursive analysis procedure based on the mechanistic-empirical method. The effects of different pavement preservation and rehabilitation strategies on pavement damage may be studied with several options for triggering timing of placement. The influence of within-project variability on the propagation of damage can be evaluated using Monte Carlo simulation. The program also permits importation of the results of HVS or track tests into the database and simulation of the experiments on the computer. This is very useful for the calibration of the mechanistic-empirical models, but may also be used for an in-depth interpretation of accelerated pavement testing results. An HVS experiment that was used for calibration of the reflection cracking and the permanent deformation models is described.
         Per  Ullidtz, Dynatest International, Denmark, pullidtz@dynatest.com
         John  Harvey, University of California, Davis
         Imad  Basheer, California Department of Transportation
         David  Jones, University of California, Davis
         Rongzong  Wu, University of California, Davis
         Jeremy David Lea, University of California, Davis
         Qing  Lu, University of South Florida

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    10-2209 - Performance of Recycled Hot-Mix Asphalt Overlays in Rehabilitation of Flexible Pavements
    Session 459
    The most widely application of recycling materials in pavements is the reuse of reclaimed asphalt pavement (RAP) to produce recycled hot mix asphalt. When designed properly, RAP mixes have demonstrated quality comparable to virgin HMAs in laboratory tests. Despite all the information available about the quality of RAP mixes, obstacles still exist to make them more frequently used in pavement engineering. This study investigates short and long term field performance of RAP mixes when compared to virgin hot mix asphalt (HMA) overlays used in flexible pavements. Data from the 18 Specific Pavement Studies-5 (SPS-5) sites from the Long Term Pavement Performance (LTPP) program located across the United States and Canada were used. Performance data was collected during periods ranging from 8 to 17 years. Repeated Measures Analysis of Variance (ANOVA) was the statistical analysis tool chosen, pairing distress measurements with survey dates to compare performance and response. The results suggest that RAP mixes have performance statistically equivalent to virgin HMA mixes for all performance indicators used. Deflections were also statistically equivalent, suggesting that RAP overlays can provide structural improvement equivalent to virgin HMA overlays.
         Regis L. Carvalho, Dynatest Consulting, Inc., rcarvalho@dynatest.com
         Hamid  Shirazi, Applied Research Associates, Inc.
         Manuel  Ayres, Airport Safety Management Consultants LLC
         Olga I. Selezneva, Applied Research Associates, Inc.

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    10-2215 - Selective Flexible Pavement Rehabilitation Based on Forensic Investigation and Deflection Analysis: Seventeen-Year Case Study in Virginia
    Session 509
    ABSTRACT This paper describes the effectiveness of combining forensic investigation and Falling Weight Deflectometer (FWD) deflection analysis in selecting the most economical best performing rehabilitation remedy for a prematurely failing thin flexible pavement. The project is a four lane divided primary road, about 3 miles long and part of Route 3 in Lancaster County, Fredericksburg District, Virginia. The two west bound lanes were constructed in 1992 with pavement structure consisting of 4.5 inches asphalt concrete on top of 6 inches dense graded aggregate, which rested on a 6 inches soil cement treated layer, on top of the natural subgrade. Within two years of service, it showed white stains at the surface, but no distresses were observed. In 1998 several areas in truck lane failed in fatigue and alligator cracking. The first rehabilitation activity, in 1998, was to mill and replace the asphalt layers, a total of 4.5 inches, without identifying the failure mechanism. This activity proved ineffective and the pavement failed in the same mode but more severely in 1999. Determination of the failure mechanism based on forensic investigation and deflection testing was finally considered, in 2000. The failure mechanism showed that dense plain aggregate which was loaded with fines acted as a weak link between the top and bottom stiff layers and lead to entrapment of moisture (in the absence of pavement edgedrain) and the premature failure due to the truck loading in the truck lane. Based on the forensic investigation and FWD deflection testing, it was decided to remove the asphalt layers and in-place cement stabilize the plain aggregate layer for the truck lane only to provide much stronger pavement by eliminating the weak link. This unique and selective rehabilitation approach resulted in two different treatments one for the truck lane, where most of the heavy loading is applied, and one for the passing lane where light loading is applied. The pavement has performed very well during the last eight years without any signs of distresses. This paper documents the lessons learned from this project, over a span of 17 years.
         Mohamed Khamis Elfino, VIrginia Department of Transportation, mohamed.elfino@vdot.virginia.gov
         Harikrishnan  Nair P.E, Virginia Center for Transportation Innovation and Research

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    10-2220 - Development of a Global Positioning System-Based Vehicle Tracking System for the Minnesota Road Research Facility
    Session 483
    One of the more important tasks in the operation of a pavement research test track involves tracking the location of individual vehicles during load response testing. The location of a vehicle’s tires has a profound effect on the values obtained from embedded pavement load response sensors. In an effort to improve the efficiency of load response testing both in the field and during analysis, a GPS-based vehicle tracking system (VTS) was developed for the MnROAD facility. Field trials to measure the accuracy of the VTS were conducted at the MnROAD facility. The VTS demonstrated its capability of tracking vehicle motion with an accuracy of ±1 inch (2.5 cm) at speeds up to 45 miles per hour (70 kph). These results matched or exceeded the accuracy obtained with the former high definition video camera used at MnROAD. Additional trials were conducted in greater Minnesota to determine the VTS operational area. Overall, the VTS received RTK level signal correction in nearly 90% of the tested areas. Two other modules were developed from the VTS. The Wireless Triggering System (WTS) provides the capability of triggering data acquisition as a test vehicle passes by an area containing pavement sensors. The Vehicle Guidance System (VGS) serves to guide test vehicle drivers through various predetermined paths. Both of these systems will significantly increase the efficiency of load response testing of pavement test sections in Minnesota.
         Thomas R. Burnham, Minnesota Department of Transportation, tom.burnham@dot.state.mn.us
         Ahmed  Tewfik, University of Minnesota, Twin Cities
         Madhavan  Vasudevan, University of Minnesota, Twin Cities

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    10-2272 - Integration of Mechanistic-Empirical Pavement Design Guide Distresses with Local Performance Indices
    Session 391
    The Pavement Management System (PMS) is the organizational entity responsible for the condition of the pavement network. Visual distress surveys are typically combined into an index to provide an overall measure of performance. Decision makers utilize these familiar indices in a number of facets. A recent survey suggests every state highway agency has implemented or plans to implement the Mechanistic-Empirical Pavement Design Guide (MEPDG). As they do so, maintaining the role these local indices play is critical for upholding the system’s continuity. However, utilizing the MEPDG output directly in calculating performance indices becomes problematic, as local distresses and MEPDG distresses are not always congruent. Therefore, there is a need to develop procedures for calculating local performance indices with locally-calibrated MEPDG output. Doing so will allow interchangeable utilization of both, while preserving the role of the local indices. The Nebraska Department of Roads (NDOR) PMS serves as a model case. NDOR employs three indices in network level PMS analyses for flexible pavements. MEPDG flexible distress models were calibrated using local agency data and input into the existing index functions. This paper explores how the current measures of network condition used in decision making can coexist with the new design methodology. This connection allows M-E analyses of fund allocation, needs estimations, performance modeling, planning, and remaining service life. In addition, local indices can provide much more meaningful failure criteria in the MEPDG to local designers. Practical methods for index calculations are introduced. Detailed guidance for local calibration is also presented.
         Scott Alan Schram P.E., Iowa Department of Transportation, scott.schram@dot.iowa.gov
         Magdy  Abdelrahman, North Dakota State University

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    10-2278 - Quantifying Effects of Particle Shape and Type and Amount of Fines on Unbound Aggregate Performance Through Controlled Gradation
    Session 651
    Construction of a pavement working platform is often needed on soft, unstable soils to provide sufficient stability and adequate immediate support for equipment mobility and paving operations without developing excessive rutting. Standard specifications may often allow the use of a wide range of aggregate materials for subgrade applications regardless of aggregate properties. The aggregate type and quality are important factors for determining the required treatment/replacement thickness. This paper describes laboratory findings from an ongoing research study at the University of Illinois aimed at evaluating aggregate cover thickness requirements on soft subgrade through characterizing strength and deformation behavior of crushed limestone and dolomite and uncrushed gravel, commonly used in Illinois for subgrade replacement and subbase. The initial laboratory phase consisted of moisture-density, unsoaked CBR, imaging based aggregate shape characterization, and shear strength tests based on a comprehensive experimental test matrix which considered both plastic and non-plastic fines (passing No. 200 sieve or 0.075 mm) blended in the engineered gradations at 4%, 8%, 12%, and 16% target fines contents. From the test results, the most important property at low fines contents (less than 8%) was the aggregate type governed by the angularity, i.e. crushed or uncrushed, and the amount of voids in the aggregate matrix. The uncrushed gravel more quickly filled the voids at lower fine percentages thus making gravel less tolerable to negative effects of increasing fines. When plastic fines (plasticity index or PI of 10 or higher) were included, the amount of fines had a drastic effect on aggregate performance.
         Debakanta  Mishra, University of Illinois, Urbana-Champaign
         Erol  Tutumluer, University of Illinois, Urbana-Champaign, tutumlue@illinois.edu
         Abbas Ahmad Butt, Engineering & Research International, Inc.

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    10-2333 - Speed Adjustment Factors for Locked-Wheel Skid Trailer Measurements
    Session 580
    Locked-wheel trailers are the predominant friction-testing tool used by state Departments of Transportation (DOTs) in the United States. They measure friction on a locked wheel on the wetted pavement surface as the wheel slides at a constant speed. The skid resistance is reported as skid number (SN) at the speed it was measured, with the standard test speed at 40 mph. Speed on most rural interstate and primary roads is rarely lower than 65 mph, whereas on most urban environments, congestion, intersections, and high-traffic volumes can lead to average traffic speeds as low as 20 mph. This paper proposes a methodology to convert the skid numbers from one speed to any desired speed using adjustment factors. The data used to develop this methodology came from measurements taken by members of the Pavement Surface Properties Consortium for the three consecutive years from 2007 to 2009. The adjustment factors were developed for the different flexible and continuously reinforced concrete pavement surfaces that are available at the Virginia Smart Road. The friction measurements performed with the skid testers presented different responses to the different pavement surface types. To separate them, principal component analysis was used and three different groups of surfaces were identified. Principal component analysis was also used to develop a friction-conversion method that used correlations between speed and texture. Correlations between speed factors and macrotexture were computed only for smooth tire skid testers because ribbed tires do not exhibit good relationships, probably because this tire is not sensitive to macrotexture.
         Gerardo W. Flintsch, Virginia Polytechnic Institute and State University
         Edgar David de León Izeppi, Virginia Tech Transportation Institute, edeleoni@vt.edu
         Kevin Kenneth McGhee, Virginia Center for Transportation Innovation and Research
         Shahriar  Najafi, Virginia Tech Transportation Institute

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    10-2355 - Calibrating the MEPDG Permanent Deformation Performance Model for Different Maintenance and Rehabilitation Strategies
    Session 387
    The different maintenance strategies available today are diverse in terms of their applicability to different pavement conditions. This research investigated the effect of different maintenance strategies on the bias correction factors necessary for the calibration of mechanistic-empirical pavement design procedures. Because each maintenance strategy is tailored to correct specific forms of distress, it can be expected that pavements that receive the right maintenance treatment will perform better than those that do not. The distress predictions are directly proportional to the value of the bias correction factors for the performance prediction model under study. A maintenance strategy proven effective in the field should have lower values for the different bias correction factors because of its ability to restrict the distress measurements to low levels. On the other hand, a maintenance strategy that has not been effective in controlling a certain distress mechanism will result in higher observed distress measurements that will translate to higher values for the different bias correction factors for the particular distress prediction model. In this study, a detailed analysis was undertaken to determine how sensitive the bias correction factors are to each of several selected maintenance strategies. The Mechanistic Empirical Pavement Design Guide (MEPDG), developed under the National Cooperative Highway Research Program (NCHRP 1-37A and 1-40D) was the main analysis tool for this investigation. The study was restricted to the permanent deformation performance models in the MEPDG. Results from this study have shown that the bias correction factors are indeed influenced by maintenance strategies. Therefore, calibration of pavement sections that have received some kind of maintenance work should be done after taking into consideration the diversity of maintenance work that has been done on them. Failure to do so will yield unrealistic pavement performance predictions.
         Ambarish  Banerjee, University of Texas, Austin
         Jorge A. Prozzi, University of Texas, Austin, prozzi@mail.utexas.edu
         José Pablo Aguiar-Moya, University of Costa Rica

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    10-2379 - Variability in Construction of Cement-Treated Base Layers: Material Properties and Contractor Performance
    Session 640
    The primary purposes of this research were to identify construction factors most correlated to specific mechanical properties of cement-treated base (CTB) layers and to determine which construction factors exhibit comparatively high variability within individual construction sections of the two pavement reconstruction projects included in this study. In addition, differences between construction sections tested in this research were evaluated. Researchers collected extensive field and laboratory data, which were analyzed using several statistical techniques. The results of this research suggest that reduced spatial variability is needed in reclaimed asphalt pavement (RAP) content, cement content, and time between mixing and compaction, which were all identified as important predictors of CTB strength in this study. Concerning full-depth reclamation projects, milling plans should be utilized to achieve improved uniformity in RAP content, and inspection protocols for encouraging improved control of cement content during construction should be implemented to ensure high-quality work. Compaction should be performed as soon as possible after mixing to minimize the adverse effects of cement hydration on the ability to achieve maximum dry density in the field. Minimizing variability in construction of CTB layers will ultimately lead to higher quality pavements that more consistently meet design expectations.
         W. Spencer Guthrie, Brigham Young University, guthrie@byu.edu
         Maile A. Rogers, Brigham Young University

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    10-2381 - Expedient Spall Repair Methods and Equipment for Airfield Pavements
    Session 214
    Selected equipment and procedures were evaluated to expedite repair of spalls with rapid-setting materials. The objective was to develop one or more methods to excavate and prepare a 2-foot-wide by 2-foot-long by 4-inch-deep spall for placement of a rapid-setting repair material in 15 minutes or less. A secondary objective was to correlate various excavation methods with a relative life expectancy of the repair. For five excavation methods, 2-foot-wide by 2-foot-long by 4-inch-deep spalls were excavated in triplicate. The spalls were subsequently repaired using a commonly-used rapid-setting cementitious repair material. The efficacy of the repair methods and equipment were evaluated based upon petrographic examination of the substrate excavation, production rate, total production rate, in-situ tensile pull-off strength, direct shear bond strength, and performance under simulated F-15 wheel loading. Each of the methods evaluated had a significant improvement in production rate over the 30-pound jackhammer, the standard Department of Defense spall repair excavation method. The most efficient method was a cold planer, which, on average, was approximately 58 percent more efficient than the jackhammer. Of the methods evaluated, only the cold planer can meet the requirement of being able to excavate 2-foot square by 4-inch deep spall in no more than 15 minutes.
         Michael I. Hammons P.E., U.S. Air Force Research Laboratory, Michael.I.Hammons@usace.army.mil
         Athar  Saeed PE, Saeed Consultants, Inc.

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    10-2395 - Use of Pavement Management Information System for Verification of Mechanistic-Empirical Pavement Design Guide Performance Predictions
    Session 391
    The performance models used in the Mechanistic-Empirical Pavement Design Guide (MEPDG) are nationally calibrated using design inputs and performance data largely obtained from the national Long-Term Pavement Performance (LTPP) program database. It is necessary to verify and calibrate MEPDG performance models for local highway agencies’ implementation by taking into account local materials, traffic information, and environmental conditions. This paper discusses the existing Pavement Management Information System (PMIS) with respect to the MEPDG and the accuracy of the nationally calibrated MEPDG prediction models for Iowa highway conditions. All the available PMIS data for interstate and primary road systems in Iowa were retrieved from the Iowa DOT’s PMIS. The retrieved databases were then compared and evaluated with respect to the input requirements and outputs for the version 1.0 of the MEPDG software. Using Iowa DOT’s comprehensive PMIS database, a total of sixteen different types of pavement sections across Iowa (not used for national calibration in NCHRP 1-37A study) were selected. A database of MEPDG inputs and the actual pavement performance measures for the selected pavement sites were prepared for verification. The accuracy of the MEPDG performance models for Iowa conditions was statistically evaluated. The verification testing showed promising results in terms of MEPDG’s performance prediction accuracy for Iowa conditions. Recalibrating the MEPDG performance models for Iowa conditions is recommended to improve the accuracy of pavement performance predictions.
         Sunghwan  Kim, Iowa State University, sunghwan@iastate.edu
         Halil  Ceylan, Iowa State University
         Kasthurirangan  Gopalakrishnan, Iowa State University
         Omar G. Smadi, Iowa State University

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    10-2435 - Optimum Use of Local Material for Roadway Base and Subbase
    Session 230
    Base materials that meet specifications are getting more difficult to get in many regions of the United States. As a result, higher quality materials have to be hauled long distances. This act would significantly increase the costs associated with roadway construction and subsequent maintenance and rehabilitation. Low quality or out-of-specification materials are usually available from local sources. If through appropriate treatment of the materials or/and structural design, the optimum use of local materials can be permitted, the construction can be accelerated and significant monetary benefits can be realized. Under many current specifications, a material can be considered low-quality for a variety of reasons such as inadequate gradation, inadequate plasticity, and inadequate strength. In many cases, the local base supplies miss the specifications by small margins. Since the criteria set in most of current specifications are experienced-based, some of the criteria used to classify a base material may be less significant than others. This paper presents a test protocol for the use of low quality flexible base materials based on the test results of materials from eight local pits in Texas to document how a low-quality material can be used on low-volume roads and still get a quality foundation layer.
         Biraj  Gautam, Marino Engineering Associates, bgautam@meacorporation.com
         Soheil  Nazarian, University of Texas, El Paso
         Deren  Yuan, University of Texas, El Paso

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    10-2604 - Long-Term Performance of Dowel Bar Retrofit in Washington State
    Session 214
    In 1993, WSDOT initiated its first full-scale dowel bar retrofit (DBR) project for the repair of a severely faulted concrete pavement. While DBR has had varied success in the United States, primarily due to construction techniques, the performance in Washington State has been very good such that DBR is considered a cost effective rehabilitation treatment for faulted concrete pavements. There are several factors that contribute to longer-term performance of DBR which include: apply prior to significant fault development (¨û inch or less); cut DBR slots to the proper depth; limit weight of jackhammers to 30 pounds; thoroughly clean DBR slot prior to placement of patching material; and extender aggregate should be of adequate size to allow consolidation of patching material around the dowel bar. To date, WSDOT has completed approximately 280 lane miles with no major DBR design or construction related issues.
         Linda M. Pierce, Applied Pavement Technology, Inc., lpierce@appliedpavement.com
         Stephen T. Muench, University of Washington
         Joe P. Mahoney, University of Washington

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    10-2620 - Investigation of the Use of Limestone Screenings in Roadway Construction
    Session 230
    Disposal of limestone screenings, or limestone fines, creates problems for many quarry operations. Much of the fines is either stockpiled or deposited back into the quarry pit. A laboratory study and pilot project was conducted to determine if limestone screenings could be stabilized and used as a structural layer in road construction. This project set forth the following objectives: determine from laboratory experiments if limestone screenings could be stabilized and used as a structural layer in road construction and evaluate the effectiveness of stabilized limestone screenings as a structural layer in road construction through performance monitoring. Compaction, unconfined compression, freezing and thawing durability, and wet-dry durability tests were performed to determine if limestone screenings could be stabilized and used as a structural layer in road construction. Falling Weight Deflectometer (FWD) tests were used to compare stiffness differences, and temperature data was used to determine the number of freezing and thawing cycles each test section underwent. Laboratory compaction and unconfined compression test results confirm that limestone screenings can be stabilized for use as a structural layer. Freezing and thawing and wet-dry durability test results show that cement kiln dust (CKD) is not an acceptable stabilizer due to poor durability performance. Class C fly ash (FA) and CKD mixtures were determined to be acceptable. Test section one (30% CKD) most likely failed due to freeze-thaw action. Visual observations show good performance of test section two (15% FA and 15% CKD) and the two control sections with no rutting or pothole formation.
         Tyson  Rupnow, Louisiana Transportation Research Center, Tyson.Rupnow@la.gov
         Vernon Ray Schaefer, Iowa State University
         David J. White, Iowa State University

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    10-2657 - Development of Maintenance Strategies to Mitigate Bridge End Damage from Water Intrusion
    Session 672
    Significant amounts of money are being spent annually on rehabilitation of damaged pavements and approach slabs near bridge ends. Investigation of such failures often reveals that saturated base and subgrade materials and/or loss of soil material from underneath the approach slab, pavement or rip rap slabs have contributed to failure. This paper reports findings from a research study entitled “Water Intrusion in Base/Subgrade Materials at Bridge Ends.” The objectives of this research project were to identify potential sources of water intrusion at bridge ends, and develop maintenance strategies that can be economically implemented in the field to minimize future occurrence of the problem. The study focused on existing, in-service bridges and remedial strategies that have been successfully implemented. A survey questionnaire was developed and sent to all the 25 TxDOT administrative districts to collect information about major factors contributing to water intrusion and bridge-end settlement problems. Field evaluations of selected bridges in four TxDOT districts were conducted, and one bridge site was selected for detailed field study. Based upon the information collected, the researchers developed a site assessment protocol to evaluate the potential of a particular site to incur water intrusion, and methods to develop optimum repair strategies. This paper reports the commonly observed sources of water intrusion at the bridge sites investigated. It also lists the preventive maintenance steps to ensure adequate service life of bridge approach pavements.
         Debakanta  Mishra, University of Illinois, Urbana-Champaign
         Priyantha Warnasuriya Jayawickrama, Texas Tech University, priyantha.jayawickrama@ttu.edu
         Phillip T Nash, Texas Tech University

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    10-2738 - Detecting Voids Under Pavements: Update on Approach of U.S. Department of Defense
    Session 244
    Several accidents involving aircraft punching through airfield pavements prompted the Navy to develop a technology for void detection. Initially, a successful void detection survey was completed at a Naval Air Station where several voids were generated by leakage of large underground drainpipes. Various methods were used such as internal videotaping of the pipes, heavy weight deflectometer (HWD) testing, ground penetrating radar (GPR), and dynamic cone penetrometer (DCP) testing. A state-of-the-art review was also completed to assess all existing technology applicable to void detection under pavements. However, the optimum technology determined (visual inspection, HWD, and DCP) still presented limitations in terms of availability and speed of data acquisition, requiring prioritization of the work. A risk analysis was then completed, establishing work prioritization within each airfield and providing a prioritization of all U.S. Navy and Marine Corps airfield pavements. An Interim Policy and Technical Guidance (IP&TG) was issued on 23 March 2000 to establish the developed void detection methodology. This is now included as an appendix in Department of Defense Unified Facilities Criteria UFC 3-260-03 and routinely applied at all 70 major Navy and Marine Corps airfields. This paper summarizes the methodology used and presents some recent field cases.
         Luis Javier Malvar, U.S. Navy Engineering Service Center, luis.malvar@navy.mil

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    10-2776 - Updating the Pavement Design Catalog for Washington State Department of Transportation: Using 1993 AASHTO Guide, Mechanistic-Empirical Pavement Design Guide, and Historical Performance
    Session 387
    This paper describes the preparation of a revised pavement thickness design catalog for the Washington State Department of Transportation (WSDOT) using the American Association of State Highway and Transportation Officials (AASHTO) 1993 Guide, the Mechanistic-Empirical Pavement Design Guide (MEPDG) and WSDOT historical pavement performance data. The selection of the design ESAL levels and performance criteria are presented followed by discussion about how AASHTO 1993 and MEPDG version 1.0 results were used to guide catalog thickness choices. Importantly, the process also includes historical pavement performance, the properties of new pavement materials, regional practices and construction variability as equally valuable inputs. Emphasis is placed on observations and issues encountered using the current AASHTO 1993 Guide and the MEPDG. The proposed design catalog has been implemented by WSDOT.
         Jianhua  Li, Washington State Department of Transportation, lijia@wsdot.wa.gov
         Jeffrey S. Uhlmeyer, Washington State Department of Transportation
         Joe P. Mahoney, University of Washington
         Stephen T. Muench, University of Washington

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    10-2941 - Necessary Assessment of Use of State Pavement Management System Data in Mechanistic-Empirical Pavement Design Guide Calibration Process
    Session 391
    Calibration and validation of the MEPDG for state DOT networks, require detailed information for a variety of pavement inputs. The biggest database resource that most states possess is their PMS (Pavement Management System). It is understandable for any DOT to maximize the use of this resource to the greatest extent possible. However, before any state utilizes PMS data in the MEPDG calibration; it is very important that a careful assessment be made of the equality of the measurements, data, etc. found in their PMS database to national LTPP values. The purpose of this paper is to review possible differences between several key PMS data found in a state PMS (ADOT) database to the LTPP database. The specific variables examined in this paper deal with distress type (rutting, cracking and roughness) and NDT backcalculated moduli to predict in-situ pavement layer properties. It was concluded that significant differences did exist between the ADOT-PMS values to LTPP measurements. Differences were found between: rut measurements, asphalt cracking, IRI, and all layer backcalculated moduli found from NDT measurements done by ADOT and those of the LTPP. As a consequence, a significant additional expense and effort may have to be provided by ADOT to calibrate the MEPDG to Arizona conditions. The paper discusses several possible reasons that would make the PMS data of a specific agency different from the LTPP data.
         Michael S. Mamlouk, Arizona State University, mamlouk@asu.edu
         Claudia E. Zapata, Arizona State University

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    10-3313 - Effect of Frequency of Pavement Condition Data Collection on Performance Prediction
    Session 219
    Monitoring pavement surface conditions over time is essential for pavement management and performance models at the network level. Time series distress data can be used to determine the remaining service life (RSL) at project level, which can then be used for all projects to assess the overall health of the pavement network. Observed field performance is also crucial for calibrating performance prediction models for pavement design purposes. Therefore, highway agencies collect pavement condition data to accomplish both policy and engineering outcomes. However, there exist differences among many agencies between the monitoring frequency used for pavement surface distress (imaging) and that used for the sensor-measured features (roughness, rut depth, and joint faulting). These differences are mainly related to the relative difficulties (cost, resources, and technology) in collecting and processing imaging data. Many agencies collect sensor data more frequently than images. Most of the highway agencies monitor pavement condition at 1-, 2-, or 3-year frequencies. Discrepancies between performance model predictions and observed field performance are conventionally attributed solely to errors in the predicted pavement distresses. In fact, there may also be significant inherent uncertainty in the measured pavement distresses due to spatial variability, sampling, and measurement errors. In addition, the frequency of distress data collection will further add to the uncertainty in performance prediction. This paper explores the effect of pavement condition monitoring frequency on pavement performance prediction. The analyses of the observed performance in several SPS-1 and SPS-2 pavement sections show that condition data collection frequency can significantly affect performance prediction, especially for structural distresses with high variability. This was clearly observed in the case of rigid pavements. Therefore, higher data collection frequency for image-based methods can reduce the associated risk in performance prediction and thus can be more effective for better decision making in the context of pavement management.
         Syed Waqar Haider P.E., Michigan State University, syedwaqa@egr.msu.edu
         Gilbert Y. Baladi, Michigan State University
         Karim  Chatti, Michigan State University

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    10-3331 - Experimental Short-Wavelength Surface Textures in Portland Cement Concrete Pavements
    Session 678
    This paper presents results from a cooperative research effort performed by the United States Federal Highway Administration (FHWA), and Canada’s Ministry of Transportation for Ontario (MTO) regarding experimental texturing of fresh Portland cement concrete pavement. The goal of the research was to develop techniques that can fabricate surface textures having most of the aggressive texture size wavelength content within the 2 to 8 mm (80 to 300 mils) wavelength range, with mean texture depth size at about 1 mm (40 mils). This wavelength range is relatively short, and it is difficult to fabricate ultra-flat textures having elevation variation only in this wavelength range. The research was initiated by the FHWA and an experimental texture test site was constructed in Ontario, Canada under the guidance of the MTO. Five texture test sections were constructed and evaluated at the Ontario test site. This paper presents an overview of the texture research and summarizes findings from the Ontario test site. The use of high resolution texture scanning profilers is described. Noise, friction and roughness properties of the different test textures are presented. Key findings regarding fabrication of short wavelength textures and their properties are summarized. The short wavelength transverse textures averaging about 8 mm (315 mils) spacing are quieter and appear to offer equal or better skid resistance to conventional deeper transverse tining having 16 mm (630 mils) groove spacing.
         Christopher Ronald Byrum PhD, PE, Soil and Materials Engineers, Inc., byrum@sme-usa.com
         Chris  Raymond, Ontario Ministry of Transportation, Canada
         Mark  Swanlund, Federal Highway Administration
         Thomas J. Kazmierowski, Golder Associates Ltd., Canada

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    10-3554 - Stiffness Characterization of Reinforced Asphalt Pavement Structures Built over Soft Organic Soils
    Session 644
    Many existing roadways in Florida are built over thick organic and peat layers which cause excessive pavement distress in the form of cracking, distortion, rutting and differential settlement. This paper presents a case study in the use of a variety of geosynthetic and steel mesh reinforcing products embedded in the asphalt overlay of SR15/US98 in southeast Florida in an effort to extend the useful life of the pavement structure. A total of 24 test sections (each 152 m long) were constructed which included 8 control sections, and 16 reinforced asphalt sections containing Glasgrid, PetroGrid, PaveTrac and Asphalt Rubber Membrane Interlayer (ARMI), at 2 different test locations representing significantly different subsoil characteristics. Prior to the rehabilitation project, series of Falling Weight Deflectometer (FWD) tests were conducted at every 15.2 m (50 feet) along the proposed test section alignment for evaluating the existing pavement capacity, and statistically determining the site variability among the test sections. Six months after the reconstruction project, FWD tests were repeated at the same locations for characterizing the performance improvements of the test sections. Though FWD tests constituted the primary evaluation technique, conventional backcalculation technique was impractical as thickness of the asphalt layer was far from uniform for having added more and more material over the years assuring a uniform pavement profile. Accordingly, FWD test results were directly employed to quantify the stiffness properties of the composite pavement based on load-deflection data thus evaluating the relative performance of the reinforced pavement sections. Based on statistical analysis of the data, it was found that the stiffness of the reinforced sections were consistently higher than the control sections, owing primarily to the reinforcements. Also, a slight trend was observed from this early age data indicating an expected relationship between the performance of the test sections and the site geotechnical characteristics.
         Khaled  Sobhan, Florida Atlantic University, ksobhan@fau.edu
         K. P. George, University of Mississippi
         Daniel  Pohly, Florida Atlantic University
         Hesham A. Ali, Florida International University

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    10-3565 - Runway Instrumentation and Response Measurements
    Session 483
    This paper presents ongoing research to measure the in-situ runway flexible pavement response to airplane traffic during its service life at the Airport of Cagliari-Elmas in Italy. Understanding how pavement materials respond to traffic and environmental loading is fundamental when designing pavements and assessing their performance. The pavement material behavior is affected by many factors (i.e., load magnitude, material properties, and environmental conditions). The influence of these factors can be simultaneously taken into account by measuring in-situ stresses and strains using embedded instruments. The pavement layers of the Cagliari-Elmas runway were instrumented with a total of 149 instruments: 36 Linear Variable Differential Transformers (LVDTs), 36 pressure cells, four Time Domain Reflectometers (TDRs), 28 T-thermocouples, and 45 HMA strain gauges. The instrumented area covers 55m2. The instrumented area allows measuring the responses during three main loading maneuvers: taking off, landing, and taxiing. The preliminary data acquired during and after the runway’s construction and prior to its opening to airplane traffic and its analysis show that the instrumentation process was a success. The instrument response testing includes FWD, truck, and airplane loading. The loading includes various loading type, magnitudes, and speed. The data acquired during the installation and before the runway was opened to traffic showed that the instrument responses were appropriate. The collected data was successfully compared to preliminary numerical simulations. Further data collection and research will be performed, especially airplane traffic data analysis. The data analysis will include the effect of the environmental data (i.e. moisture and temperature) and airplane configuration and speed. Such data resulting from this research have the potential to support and improve runway pavement design as well as to improve the evaluation process for new and existing runway pavements in terms of their performance and damage prediction.
         Imad L. Al-Qadi, University of Illinois, Urbana-Champaign, alqadi@illinois.edu
         Silvia  Portas, University of Cagliari, Italy
         Mauro  Coni, University of Cagliari, Italy
         Samer  Lahouar, Institut Supérieur des Sciences Appliquées et de Technologie de Sousse, Tunisia

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    10-3726 - Assessment of Data Quality for Evaluations of Manual Pavement Distress
    Session 450
    Assessment of present asset condition is a task of major relevance in a transportation agency asset management program that does not only provide information on the current situation of the asset, but it also helps the asset manager to identify future needs and to make decisions on required maintenance and rehabilitation activities. While low-volume roadways represent a great proportion of the total road network in the United States, little research has been done on the management of these assets. For roadway condition assessment, two major data collection techniques have been identified. Automated techniques have been found to be safer and quicker, but manual condition surveys have been proven to be more precise and cost-effective. In the case of low-volume roadways, where funds available to asset manager are more limited, manual condition surveys have been preferred. Nevertheless, manual condition surveys still have the stigma of the potential subjectivity involved in their results. As a result, asset manager would benefit from a system for assuring quality on manual condition surveys. Such a system would need to be easily implementable and to without doubt identify potential and actual data collection issues. The benefit of this system is that it would provide guidance during the data collection minimizing the risk of subjectivity. The present paper proposes a Data Quality Assessment Framework and presents a case study of its implementation in the Northern New Mexico Pavement Evaluation Program. The proposed system can be used as part of an asset management program, and could be particularly beneficial in the case of low-volume roads.
         Susan  Bogus, University of New Mexico
         Giovanni Ciro Migliaccio, University of Washington, gianciro@uw.edu
         Arturo  Cordova, University of New Mexico

     

    Pedestrians and Cycles

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    10-3437 - Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey
    Session 313
    Carsharing has grown considerably in North America during the past decade and has flourished within metropolitan regions across the United States and Canada. The result has been a new transportation landscape, which offers urban residents an alternative to automobility without car ownership. As carsharing has expanded, there has been a growing demand to understand its environmental impacts. This paper presents the results of a North American carsharing member (N = 6,281) survey. The authors establish a “before-and-after” analytical design with a specific focus on carsharing’s impacts on household vehicle holdings and the aggregate vehicle population. The results show that carsharing members reduce their vehicle holdings to a degree that is statistically significant. The average vehicles per household of the sample drops from 0.47 to 0.24. Most of this shift constitutes one-car households becoming carless. The average fuel economy of vehicles shed by carsharing households is on average 10 miles per gallon (mpg)/16 kilometers per gallon (kmpg) less than the carsharing vehicle most often used by respondents. The median age of vehicles shed by carsharing households is 11 years, but the distribution covers a considerable range. A sensitivity analysis of the sample with respect to the membership population suggests that carsharing has taken between 75,000 to 94,000 vehicles off the road, which equates to 9 to 12 vehicles (including shed and postponed auto purchases) for each carsharing vehicle.
         Elliot W. Martin, University of California, Berkeley, elliot@berkeley.edu
         Susan A. Shaheen, University of California, Berkeley
         Jeffrey R. Lidicker, University of California, Berkeley

     

    Public Transportation and Ferries

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    10-0471 - Agency-Initiated Bus Noise Reduction for Los Angeles Metro Orange Line
    Session 523
    This paper presents noise control efforts of the Los Angeles County Metro Orange Line, one of the first bus rapid transit (BRT) systems in the U.S. through residential areas. The Orange Line is a 14-mile (22.5 km) dedicated BRT corridor in the San Fernando Valley in Los Angeles County that utilizes 60-foot (18.3 m), articulated vehicles powered by compressed natural gas engines. Noise control efforts included noise mitigation design features, establishing noise emission values of the buses, modeling of the operational noise to determine location where residual impacts occur, establishing background noise levels, monitoring operational noise levels, mitigation of residual noise impacts, and retrofitting the fleet with new mufflers. The paper discusses the results of an agencies commitment to resolving community environmental noise issues and provides guidance regarding noise modeling and noise specification of city buses.
         Ramon  Nugent, Acentech Inc., rnugent@acentech.com
         McDuffee  Mathew, Acentech Inc.
         Carl Peter Ripaldi, Los Angeles County Metropolitan Transportation Authority
         Michael  Chang, Los Angeles County Metropolitan Transportation Authority

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    10-3437 - Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey
    Session 313
    Carsharing has grown considerably in North America during the past decade and has flourished within metropolitan regions across the United States and Canada. The result has been a new transportation landscape, which offers urban residents an alternative to automobility without car ownership. As carsharing has expanded, there has been a growing demand to understand its environmental impacts. This paper presents the results of a North American carsharing member (N = 6,281) survey. The authors establish a “before-and-after” analytical design with a specific focus on carsharing’s impacts on household vehicle holdings and the aggregate vehicle population. The results show that carsharing members reduce their vehicle holdings to a degree that is statistically significant. The average vehicles per household of the sample drops from 0.47 to 0.24. Most of this shift constitutes one-car households becoming carless. The average fuel economy of vehicles shed by carsharing households is on average 10 miles per gallon (mpg)/16 kilometers per gallon (kmpg) less than the carsharing vehicle most often used by respondents. The median age of vehicles shed by carsharing households is 11 years, but the distribution covers a considerable range. A sensitivity analysis of the sample with respect to the membership population suggests that carsharing has taken between 75,000 to 94,000 vehicles off the road, which equates to 9 to 12 vehicles (including shed and postponed auto purchases) for each carsharing vehicle.
         Elliot W. Martin, University of California, Berkeley, elliot@berkeley.edu
         Susan A. Shaheen, University of California, Berkeley
         Jeffrey R. Lidicker, University of California, Berkeley

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    10-4092 - Mitigating Excessive Idling of Transit Buses
    Session 523
    In recent years, much media attention has been paid to research developments related to three types of diesel vehicles: School buses, long-haul trucks and transit buses. Transit bus emissions studies get attention often because the public wants to know if transit agencies are spending public dollars efficiently and with concern for public health. The public health and environmental effects of transit bus idling and strategies to mitigate idling practices need to be understood. Most transit bus idling is considered “non-discretionary,” occurring while a bus is stuck in traffic or making a stop along its route. There are, however, some scenarios in which transit buses idle unnecessarily, and despite the fact that many solutions exist to limit idling from these buses, these solutions have not garnered much interest from transit agencies, researchers or lawmakers. This paper will review the causes and effects of transit bus idling, and will examine the potential costs and benefits of employing idling-reduction technologies and policies on the bus fleet of a large metropolitan transit agency in the Midwest to limit fuel consumption and emissions. The paper is organized as follows: Economic, environmental and health effects of diesel emissions are discussed in the background section, as well as current anti-idling public policy. The research methodology is described, and causes of excessive bus idling at the Chicago Transit Authority are discussed as well as potential solutions. Idling-reduction technologies are examined to determine which provides the greatest economic and environmental benefit for the lowest cost. The conclusion presents specific recommendations for the Chicago Transit Authority.
         Emily  Ziring, University of Illinois, Chicago
         P. S. Sriraj, University of Illinois, Chicago, sriraj@uic.edu

     

    Research and Education

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    10-4064 - New York Metropolitan Transportation Council Staff Training Program: Collaboration Between NYMTC and New York University Wagner Rudin Center
    Session 317
    From September 2008 to April 2009, the New York Metropolitan Transportation Council collaborated with the NYU Wagner Rudin Center on a unique program to offer training courses to professional transportation staff from regional transportation agencies. The Program consisted of 23 courses organized within three distinct modules, Skill Building, Transportation Policy, and Tools and Methods. Tailored for line and mid-level staff as a parallel and complimentary track to the already established NYMTC Executive Education Program developed in the 1990s, 86% of Program participants reported the curriculum to be of strong content and with high relevance to their jobs and professional development. The Program offers a model for MPO and university research center collaboration on continuing professional education for transportation professionals. Connecting agencies through MPOs with university educational resources aligns the training goals to the MPO's regional objectives as well as national transportation education initiatives.
         Lina  Duran, NYU Wagner Rudin Center for Transportation Policy and Management, linaduran@nyu.edu
         Adam  Gromis, NYU Wagner Rudin Center for Transportation Policy and Management
         Kuo-Ann  Chiao, New York Metropolitan Transportation Council

     

    Safety

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    10-0087 - New Test Level 2 Rough Stone Masonry Guardwall
    Session 277
    A minimum mounting-height rough stone masonry guardwall was designed and successfully crash tested to meet Test Level 2 (TL-2) safety performance criteria found in NCHRP Report 350. Several design concepts were considered for providing shear transfer between the top capstones and the inner core wall. The new design utilizes steel angle segments anchored to the core wall with the upper leg recessed into saw-cuts placed in the capstones. LS-DYNA simulations were performed with varying barrier heights to evaluate the propensity for vehicular instabilities and barrier override. Two crash tests were performed. The first test was performed on a 22 in. tall guardwall using a 2000P pickup truck impacting at a speed of 44.4 mph and at an angle of 24.2 degrees. The second test was performed on a 20 in. tall guardwall using another 2000P vehicle impacting at a speed of 43.6 mph and at an angle of 24.4 degrees. Both crash tests provided acceptable safety performance. Although the 20 in. tall parapet adequately contained and redirected the pickup truck at the TL-2 conditions, barrier performance was slightly degraded over that observed in the 22 in. tall parapet. Based on the results of this study and for new construction, it is recommended that the rough stone masonry guardwall system be implemented using a nominal top mounting height of 22 in. relative to the traveled way. A significant benefit of this nominal height is that roadways requiring resurfacing could be accommodated using a 2 in. pavement overlay placed adjacent to the barrier system.
         John D. Reid, University of Nebraska, Lincoln, jreid@unl.edu
         Ronald K. Faller P.E., University of Nebraska, Lincoln

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    10-0431 - Termination and Transition of Temporary Concrete Barrier
    Session 277
    For the research studies described herein two new technologies were developed for temporary concrete barriers (TCBs). The first project developed an economical method for terminating and anchoring the upstream end of TCB systems. The second developed a TCB approach transition for attachment to permanent concrete median barriers. Both designs were configured for use with the Kansas F-shape TCB that is currently used by several states participating in the Midwest Pooled Fund Program. These efforts were performed in accordance with the Test Level 3 (TL-3) guidelines found in the Manual for Assessing Safety Hardware 2008 (MASH). The termination and anchorage system allowed for a significant reduction in the number of barrier segments required upstream from the length of need and for use in anchoring a free-standing TCB system. The anchorage system was configured to effectively constrain the end of the TCB system for impacts as far upstream as the first anchored barrier segment. Full-scale crash testing demonstrated that the impacting vehicle was safely and smoothly redirected, and the test was judged acceptable according to the TL-3 safety criteria set forth in MASH. The approach transition was developed for attaching free-standing TCBs to permanent concrete median barriers. Evaluation of the approach transition required testing at two Critical Impact Point (CIP) locations. Full-scale crash testing demonstrated that the impacting vehicle was safely and smoothly redirected, and the testing of the approach transition was judged acceptable according to the TL-3 safety criteria set forth in MASH.
         Robert  Bielenberg, University of Nebraska, Lincoln, rbielenberg2@unl.edu
         Scott K. Rosenbaugh, Midwest Roadside Safety Facility
         John D. Reid, University of Nebraska, Lincoln
         Ronald K. Faller P.E., University of Nebraska, Lincoln
         Karla A. Lechtenberg, University of Nebraska, Lincoln

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    10-0741 - Implementation of Structural Control Measures to Mitigate Avalanche Hazard Along Transportation Corridors
    Session 600
    Avalanche hazards along transportation corridors in the United States have traditionally been addressed through the use of forecast their potential and actively controlling them through explosive release while the roadway is closed. This approach reduces the threat of avalanches cascading onto the roadway and thus reduces danger to the traveling public. However, active control methods cannot always be implemented in a timely fashion, can be ineffective, and can have large associated economic impacts. An alternative to active control is passive, structural avalanche defenses. They are “passive” in that they do not require the efforts of winter maintenance personnel during winter storm periods. Structural defense measures include snow sails, snow supporting structures, and snow sheds. Despite their extensive use in Europe and their potential for effectively reducing avalanche hazards, there are very few examples to be found in the United States. The potential for negative impacts to the visual attributes of the landscape has been a significant reason for their lack of domestic use. This paper discusses several types of structural defense measures, criteria for their selection at a given site, and their relative effectiveness. Passive structural defense measures designed for implementation at the 151 Avalanche on US Route 89/191near Jackson, Wyoming are described. Details are given on important collaborations between landscape architects and engineers that led to successfully addressing National Environmental Policy Act (NEPA) requirements for retention of visual attributes at the 151 Avalanche site in the presence of snow support structures deployed for the purpose of avalanche hazard reduction.
         Joshua  Hewes, Northern Arizona University, Joshua.Hewes@nau.edu
         Rand  Decker, Northern Arizona University
         Scott  Merry, Kleinfelder, Inc.
         Jamie M Yount, Wyoming Department of Transportation

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    10-1768 - Improving Road Weather Hazard Products with Vehicle Probe Data: Vehicle Data Translator Quality-Checking Procedures
    Session 211
    One of the goals of the Research and Innovative Technology Administration’s IntelliDriveSM initiative is for the public and private organizations that collect, process, and generate weather products to utilize vehicle sensor data to improve weather and road condition hazard products. It is possible that some users will not be able to — or not want to — contend with the complexities associated with vehicle data, such as data quality, representativeness, and format. With funding and support from the U.S. Department of Transportation’s (USDOT) Research and Innovative Technology Administration (RITA) IntelliDriveSM initiative and direction from the Federal Highway Administration’s (FHWA) Road Weather Management Program, the National Center for Atmospheric Research (NCAR) is conducting research to develop a Vehicle Data Translator (VDT) to address these vehicle-based data challenges. This paper first describes the VDT quality-check (QCh) concept and then examines QCh pass rates for temperature and pressure data collected from 11 specially-equipped vehicles operating in the Detroit Testbed in April 2009. Results show that temperature pass rates are higher than pressure. Additionally, pass rates are affected by vehicle type, vehicle speed, ambient temperature, and precipitation occurrence for both temperature and pressure.
         Sheldon  Drobot, National Center for Atmospheric Research, drobot@ucar.edu
         Michael Benjamin Chapman, National Center for Atmospheric Research
         Elena  Schuler, National Center for Atmospheric Research
         Gerry  Wiener, National Center for Atmospheric Research
         William Paul Mahoney III, National Center for Atmospheric Research
         Paul A. Pisano, Federal Highway Administration
         Ben  McKeever, Research and Innovative Technology Administration

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    10-2189 - Limits of Acceptable Rail-and-Post Deflection in Crash-Damaged Strong-Post W-Beam Guardrail
    Session 457
    The guidelines for the testing of strong-post w-beam guardrail, intended to ensure the safety of errant vehicles, are specified in the National Cooperative Highway Research Program (NCHRP) Report 350. A limitation of these tests is that they are always performed on new, undamaged guardrail whereas guardrail along highways is in a continuous cycle of damage and repair. No tests have ever evaluated the performance of deflection-damaged guardrail. A full scale, two part crash test was conducted to evaluate the performance of a guardrail with 14.5 inches (368 mm) of prior crash damage. When this guardrail was struck by a 4409 lb (2000 kg) pickup truck traveling at 62 mph (100 kph) the vehicle vaulted and came to rest upright behind the barrier. A critical factor was the failure of a post to separate from the rails. Finite element models were employed to evaluate the guardrail performance at lower levels of deflection. The crash tests and finite element models demonstrated that post and rail deflection of 11 inches (279 mm) or higher resulted in vaulting. Repair was recommended for strong-post w-beam guardrail with combined rail and post deflection exceeding 6 inches (152 mm). This limit allows a margin of safety for variations in soil strength and vehicle height. The existence of rail only deflection had a minimal effect on the crash performance up to the maximum tested value of 6 inches.
         Carolyn E. Hampton, Virginia Polytechnic Institute and State University, champton@vt.edu
         Douglas John Gabauer, Bucknell University
         Hampton Clay Gabler, Virginia Polytechnic Institute and State University

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    10-2303 - Low-Profile Barrier with TL-3 Modification
    Session 277
    The Low-Profile Barrier (LPB) is only 20 inches high with predictably improved visibility of intersecting and/or surrounding traffic compared to the 32-inch standard safety shape. The initial LPB was developed by Texas Transportation Institute (TTI) and Texas Department of Transportation (TxDOT) in 1995 and approved by FHWA for Test Level 2 (TL-2) (45 mph) in 1997 and 1998. Since that time, it has become a standard in Texas in construction zones and also has been applied to permanent installations. Florida engineers have developed their own single-sided LPB using TTI’s profile. A new advantage has been discovered that should have a significant influence on permanent installations. Design consultants have reported spectacular potential savings in soil/rock earth work in mountainous terrain if a 20-inch LPB can be used instead of the common 32 inch safety shape. This is due to the AASHTO requirement for sight distance around horizontal curves. These applications often require TL-3 performance. TL-3 performance was achieved by using the existing LPB as the base and developing a stabilizing rail that attaches to the top of the LPB at connection points. A retrofit of the current LPB was tested for both visibility, and for pickup rollover stability, the flaw in LPB TL-2 performance. NCHRP Report 350 test 3-11 was performed on two designs to evaluate the modified barrier in containing and redirecting a pickup. This report includes details of the LPB 3 testing.
         Jeremy  Klam, Texas A&M Transportation Institute
         Don L. Ivey PhD.,P.E., Scientific Inquiry, Inc.
         Wanda L Menges, Texas A&M Transportation Institute , w-menges@tamu.edu

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    10-2804 - Roadway Departure and Impact Conditions
    Session 612
    In-depth accident data was collected in order to investigate vehicle impact conditions (i.e., crash severity, impact speed, impact angle, and orientation) for crashes with roadside obstacles and features. Descriptive statistics of these variables are presented, including statistics for the data segregated by highway class, speed limit and access control. Relationships between impact conditions and these segregating factors are explored. Statistical tests were applied to investigate the association between speed and angle, and univariate distributions were fitted for these two variables. It was found that impact speed and impact angle are independent for most highway classes when segregated by highway class and that they have a relatively weak negative correlation. It was also found that both impact speed and angle data for all highway classes follow a normal distribution. Joint impact distributions were then determined using the Bivariate Normal distribution and are presented in this paper. The findings of this study are of significant importance to establish and/or reinforce full-scale vehicle crash testing guidelines, to benefit-cost analysis procedures, and to highway designers who seek for more detailed information on probabilities of impact conditions for different highway classes.
         Francisco Daniel B. Albuquerque, Midwest Roadside Safety Facility, dbenicio@huskers.unl.edu
         Dean L. Sicking, University of Nebraska, Lincoln
         Cody S. Stolle, Midwest Roadside Safety Facility

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    10-3060 - Diagnosing Road Weather Conditions with Vehicle Probe Data: Results from Detroit IntelliDrive Field Study
    Session 211
    Over the past two years, the USDOT/Research and Innovative Technology Administration funded an IntelliDriveSM vehicle probe data collection testbed in the Northwest Detroit area (the Detroit Testbed). The purpose of the testbed was to provide the infrastructure for both public and private organizations to collect, process, and generate a robust observation dataset for multiple purposes (e.g., crash avoidance, automated toll services, weather diagnostics). During April 2009, a weather specific field study was performed over an 11-day period. The resulting dataset was processed by a Vehicle Data Translator (VDT), which parsed, quality controlled, and combined these data (with ancillary weather data) in the generation of road-weather specific algorithms. This paper briefly describes the VDT concept and then examines the accuracy of the quality-controlled temperature and pressure data (for several different stratifications) collected from 11 specially-equipped vehicles operated during the study time period. Results show that the vehicles accurately measure the temperature (compared with a nearby fixed weather station; KDTW), but are not as accurate at measuring the barometric pressure. In addition, stratification by speed, vehicle type, time of day, and occurrence of precipitation do not affect the accuracy of the temperature and barometric pressure measurements
         Michael Benjamin Chapman, National Center for Atmospheric Research, mchapman@ucar.edu

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    10-3391 - Development of Guidelines for Anchor Design for High-Tension Cable Guardrails
    Session 457
    High tension cable guardrail is becoming increasing popular in median and roadside applications due to the promise of reduced deflections upon impact and reduced maintenance. As the performance of these systems is observed in service, there is a growing concern over the end anchorage foundation performance of current systems. Foundations for high tension systems must not only be capable of restraining the impact load of a vehicle but must also must restrain the initial pretension on the cable system as well as temperature induced loads. While it is acceptable for a many roadside safety devices to require foundation repair after impact, this is not acceptable for high tension cable systems as the temperature induced loads can be greater than those loads applied during impact. Foundation deflection can reduce cable tension, increasing deflection of the system during impact and letting the cables sag after impact. The soil conditions in which these foundations are placed vary significantly. This paper considers the potential impact, tension, and temperature loads and develops a set of suggested foundation designs to accommodate a range on in situ soil conditions. These designs will vary significantly in different areas around the nation due to variations in both weather and in situ soil conditions. Deflection during full-scale crash tests may not accurately represent the foundation deflection that will be experienced in the field.
         Ling  Zhu, Midwest Roadside Safety Facility
         John  Rohde, University of Nebraska, Lincoln, jrohde@unl.edu

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    10-3966 - Application of Precast Concrete Barrier Adjacent to Steep Roadside Slope
    Session 277
    When concrete barriers are installed adjacent to drop-offs or steep roadside slopes such as 1.5H:1V, a cast-in-place concrete moment slab is usually attached to the base of the barrier to resist lateral and overturning forces during vehicle impact. Cast-in-place construction can require more time on site to build forms, pour the concrete, and allow for curing. This results in an increase in disruption to traffic and more exposure for construction workers. Furthermore, the installation of a moment slab is very costly and requires an additional construction phase to build the slab. Since the slab is normally under the shoulder and possibly the lanes, the disruption of traffic flow is increased. This paper presents a new application of a precast 42-inch tall single slope concrete barrier for use in front of steep slopes, without requiring a moment slab. The lateral movement of the barrier is restricted by embedding it in soil. This design also reduces the embankment behind the barrier to two feet. The embedded barrier application was successfully evaluated under Manual for Assessing Safety Hardware test level 3 criteria. The permanent deflection of the barrier was 5.5 inches. The use of the embedded concrete barrier in lieu of the typically installed barrier with a moment slab is expected to result in cost savings of approximately $300 per linear foot and reduced time to construct.
         Nauman M. Sheikh P.E., Texas A&M Transportation Institute , nauman@tamu.edu
         Roger P. Bligh, Texas A&M Transportation Institute
         Richard B Albin, Federal Highway Administration
         David K. Olson, Washington State Department of Transportation

     

    Soil Mechanics

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    10-0317 - Energy Efficiency and Rod Length Effect in Standard Penetration Test Hammers
    Session 236
    Please Update this!
         Michael D. Valiquette, North Carolina Department of Transportation
         Brent  Robinson, North Carolina State University, Raleigh, brrobins@ncsu.edu
         Roy H. Borden, North Carolina State University, Raleigh

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    10-0480 - Investigation and Implications of Mechanically Stabilized Earth Wall Corrosion in Nevada
    Session 244
    Nevada Department of Transportation has over 150 mechanically stabilized earth (MSE) walls at 39 locations. Recently, high levels of corrosion were observed due to accidental discovery at two of these locations. The resulting investigations of these walls produced direct measurements of metal corrosion losses and electrochemical properties of the MSE backfill. One MSE wall was replaced with a cast-in-place tie-back wall at great expense. The paper incorporates a statistical analysis that addresses the variability in measured corrosion and electrochemical data to predict corrosion behavior. It is shown that the original MSE backfill approval electrochemical test results are significantly different from those measured in post-construction investigations. A correlation has been developed between two distinctly different soil resistivity test methods, namely the Nevada T235B and AASHTO T-288 methods. Over-prediction made by the Nevada T235B method has proved detrimental to the service lives of MSE walls. The internal stability analyses (using AASHTO 2007 LRFD) of two remaining MSE walls at an intersection were also performed using corrosion loss models developed from the statistical analysis. The findings of the study were subsequently extrapolated to other Nevada MSE walls. Through review of the backfill approval data, suspect Nevada MSE walls have been identified relative to estimated backfill aggressiveness.
         John David Thornley, Hattenburg Dilley & Linnell, jthornley@hdlalaska.com
         Raj  Siddharthan, University of Nevada, Reno
         Barbara  Luke, University of Nevada, Las Vegas
         John Mark Salazar, Nevada Department of Transportation

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    10-0550 - Evaluation of Characterization and Performance Modeling of Cementitiously Stabilized Layers in the Mechanistic-Empirical Pavement Design Guide
    Session 291
    Cementitious stabilization of aggregates and soils is an effective technique to increase the stiffness of the base and subbase layers and modify the structural response of pavement: for instance, cementitious bases can improve the fatigue behavior of asphalt surface layers and subgrade rutting over the short- and long-term. However, the stabilization of soils and aggregates with cement can lead to additional distresses such as shrinkage and fatigue in the stabilized layers. Extensive research has been done to test these materials experimentally and characterize them, however, very little of this research attempts to correlate the mechanical properties of the stabilized layers with their performance. MEPDG provides a promising theoretical framework for the modeling of CSMs performance. However, significant improvements are needed to bring the modeling of semi-rigid pavements in MEPDG to the same level as that of flexible and rigid pavements. Furthermore, the design of pavement systems with stabilized layers is disadvantaged by the fact that the Mechanistic Empirical Pavement Design Guide (MEPDG) does not model cementitiously stabilized materials (CSMs) in the manner similar to those for hot mix asphalt (HMA) or portland cement concrete (PCC) materials; as a result, performance gains from stabilized layers are difficult to assess using the MEPDG. The purpose of this paper is to evaluate the current characterization of CSMs and bring to light issues with their modeling in MEPDG. Addressing of these issues will help the designer to quantify the benefits of stabilization and improve pavement service life.
         Priyam  Saxena, University of Minnesota, saxe0034@umn.edu
         Derek  Tompkins, University of Minnesota
         Lev  Khazanovich, University of Minnesota
         Jose Tadeu Balbo, University of Sao Paulo, Brazil

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    10-1168 - Implementation of Stabilized Blended Calcium Sulfate Materials in Flexible Pavement Design and Construction
    Session 243
    The Blended Calcium Sulfate (BCS), a recycled fluorogypsum waste material, has been used in Louisiana as a pavement base layer for more than a decade. Without further chemical stabilization, the major concern of using raw BCS as a pavement structural layer is its moisture susceptibility. It could cause both short-term construction difficulties and long-term performance problems. In order to improve the moisture susceptibility of BCS, various cementitious agents were used in the laboratory for BCS stabilization. To further verify the efficiency of BCS stabilization schemes obtained from laboratory and assess the field performance for stabilized BCS materials as well as potential cost benefits, three pavement test sections were constructed and tested using the Accelerated Loading Facility (ALF) device. Both laboratory and field test results indicated that a grade 120 granulated ground blast furnace slag (GGBFS) of 10 percent by volume stabilized BCS material possessed a superior performance over raw BCS in terms of water resistance, durability and good long-term performance. Field test results further demonstrated that the GGBFS stabilized BCS base outperformed both a regular crushed stone base and a fly ash stabilized BCS base by a significantly large margin. A life-cycle cost analysis proved that, besides its outstanding laboratory and field performance, using the GGBFS stabilized BCS can provide a substantial long-term savings over regular crushed stone and fly ash stabilized BCS bases in a 30-year pavement design life period.
         Zhong  Wu, Louisiana Transportation Research Center, zhongwu@ltrc.lsu.edu
         Zhongjie  Zhang, Louisiana Department of Transportation and Development
         Mingjiang  Tao, Worcester Polytechnic Institute

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    10-1653 - Characterization of Two-Layer Soil System Using a Light Weight Deflectometer with Radial Sensors
    Session 344
    Non-destructive tests to estimate stiffness modulus, such as the light weight deflectometer (LWD), have experienced increased popularity, but very little research has been performed to evaluate the LWD with radial sensors. Results are presented from LWD testing with radial sensors that measured the deflection bowl on one- and two-layer field test beds consisting of unbound materials. LWD testing produced a measureable deflection bowl on medium stiffness granular materials to a radial sensor spacing of 750 mm (30 in). When limited to a stiff over soft layered system, the LWD with radial sensors demonstrated the ability to accurately backcalculate layered moduli. Backcalculated moduli closely matched laboratory determined moduli from triaxial testing at a similar stress state as in the field. The measurement depth for the LWD with radial sensors was found to be 1.8 times plate diameter versus the measurement depth of conventional LWD testing of 1.0 to 1.5 times plate diameter. The LWD with radial sensors was able to measure deeper than conventional LWD testing because the radial geophones measure vertical surface deflections caused almost entirely by strains in deeper material. As compared to other configurations, the 300 and 600 mm (12 and 24 in) radial sensor configuration is recommended for unbound materials because it produced the most accurate moduli backcalculation results and captures deflections critical to the backcalculation process.
         Christopher T. Senseney, Colorado School of Mines, csensene@mines.edu
         Michael A. Mooney, Colorado School of Mines

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    10-1755 - Mechanistic Laboratory Evaluation and Field Construction of Recycled Concrete Materials for Use in Road Substructures
    Session 243
    Conventional flexible pavement systems require significant volumes of quality aggregates. Unfortunately, most urban centres are faced with depleted aggregate sources. Given recent significant urban infrastructure renewal as well as increased costs associated with landfilling concrete rubble, there is potential to optimize the reclamation and recycling of Portland cement concrete (PCC) and hot mix asphalt concrete (HMAC) rubble through innovative use of these materials in road rehabilitation. The primary objective of this study was to demonstrate the ability to reclaim, process, and recycle stockpiled concrete materials in order to provide improved structural mechanistic-climatic material properties. As part of this objective, it is desirable to meet or exceed the mechanical properties of conventional granular road materials. This research is based on advancements of the “Green Streets” Infrastructure Program in the City of Saskatoon. A second objective of this research was to pilot the field application of reclaimed and recycled asphaltic concrete and PCC rubble in a typical urban road reconstruction application. Recycled HMAC and PCC materials were used in a pilot re construction project of a road exhibiting substructure moisture problems and structural failure. This study showed that recycled HMAC and PCC rubble materials could be processed to achieve mechanistic laboratory properties that exceed those of conventional granular base materials. This study also demonstrated efficient constructability and high end-product structural value of a typical rehabilitated urban road structure test section in the City of Saskatoon utilizing recycled HMAC and PCC rubble.
         Curtis F. Berthelot Ph.D.,P.Eng., University of Saskatchewan, Canada, curtis.berthelot@usask.ca
         Rielle  Haichert, PSITechnologies Inc., Canada
         Diana  Podborochynski, Pavement Scientific International, Canada
         Colin  Wandzura, PSI Technologies, Inc., Canada
         Brian  Taylor P.Eng., Consultant, Canada
         Duane Joel Guenther, City of Saskatoon, Canada

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    10-2267 - Implementation of Quality Management of Base Materials with Seismic Methods: Case Study in Texas
    Session 344
    Existing practices for field quality management of unbound layers (base, subbase and subgrade) rely on the adequacy of parameters such as density and moisture content. However, increasingly accepted mechanistic-empirical pavement design is primarily based on the strength and stiffness of the pavement layers. Therefore, methods to measure the modulus or stiffness of soil layers in the field shortly after construction may lead to a more reliable implementation of the design process. Modulus-based quality management methods may be more beneficial than traditional techniques because they test materials in their natural state. Nondestructive testing (NDT) methods allow for obtaining modulus of pavement layers in a rapid way. Seismic methods are one example of available methods that can be used to measure the modulus of finished unbound layers. Seismic methods are particularly attractive because they yield the same parameter (low-strain modulus) for the lab and field tests and do not require any backcalculation process. Performing the simplified seismic laboratory and field tests along with more traditional tests may lead to a smooth integration of design procedures along with pavement evaluation. In this paper, an overall approach that integrates design, laboratory and field quality management processes is presented. To evaluate the proposed method, a case study was investigated to corroborate its usefulness and convenience.
         Manuel  Celaya, University of Texas, El Paso, mcelaya@aidpe.com
         Soheil  Nazarian, University of Texas, El Paso
         Deren  Yuan, University of Texas, El Paso

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    10-2379 - Variability in Construction of Cement-Treated Base Layers: Material Properties and Contractor Performance
    Session 640
    The primary purposes of this research were to identify construction factors most correlated to specific mechanical properties of cement-treated base (CTB) layers and to determine which construction factors exhibit comparatively high variability within individual construction sections of the two pavement reconstruction projects included in this study. In addition, differences between construction sections tested in this research were evaluated. Researchers collected extensive field and laboratory data, which were analyzed using several statistical techniques. The results of this research suggest that reduced spatial variability is needed in reclaimed asphalt pavement (RAP) content, cement content, and time between mixing and compaction, which were all identified as important predictors of CTB strength in this study. Concerning full-depth reclamation projects, milling plans should be utilized to achieve improved uniformity in RAP content, and inspection protocols for encouraging improved control of cement content during construction should be implemented to ensure high-quality work. Compaction should be performed as soon as possible after mixing to minimize the adverse effects of cement hydration on the ability to achieve maximum dry density in the field. Minimizing variability in construction of CTB layers will ultimately lead to higher quality pavements that more consistently meet design expectations.
         W. Spencer Guthrie, Brigham Young University, guthrie@byu.edu
         Maile A. Rogers, Brigham Young University

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    10-2657 - Development of Maintenance Strategies to Mitigate Bridge End Damage from Water Intrusion
    Session 672
    Significant amounts of money are being spent annually on rehabilitation of damaged pavements and approach slabs near bridge ends. Investigation of such failures often reveals that saturated base and subgrade materials and/or loss of soil material from underneath the approach slab, pavement or rip rap slabs have contributed to failure. This paper reports findings from a research study entitled “Water Intrusion in Base/Subgrade Materials at Bridge Ends.” The objectives of this research project were to identify potential sources of water intrusion at bridge ends, and develop maintenance strategies that can be economically implemented in the field to minimize future occurrence of the problem. The study focused on existing, in-service bridges and remedial strategies that have been successfully implemented. A survey questionnaire was developed and sent to all the 25 TxDOT administrative districts to collect information about major factors contributing to water intrusion and bridge-end settlement problems. Field evaluations of selected bridges in four TxDOT districts were conducted, and one bridge site was selected for detailed field study. Based upon the information collected, the researchers developed a site assessment protocol to evaluate the potential of a particular site to incur water intrusion, and methods to develop optimum repair strategies. This paper reports the commonly observed sources of water intrusion at the bridge sites investigated. It also lists the preventive maintenance steps to ensure adequate service life of bridge approach pavements.
         Debakanta  Mishra, University of Illinois, Urbana-Champaign
         Priyantha Warnasuriya Jayawickrama, Texas Tech University, priyantha.jayawickrama@ttu.edu
         Phillip T Nash, Texas Tech University

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    10-2738 - Detecting Voids Under Pavements: Update on Approach of U.S. Department of Defense
    Session 244
    Several accidents involving aircraft punching through airfield pavements prompted the Navy to develop a technology for void detection. Initially, a successful void detection survey was completed at a Naval Air Station where several voids were generated by leakage of large underground drainpipes. Various methods were used such as internal videotaping of the pipes, heavy weight deflectometer (HWD) testing, ground penetrating radar (GPR), and dynamic cone penetrometer (DCP) testing. A state-of-the-art review was also completed to assess all existing technology applicable to void detection under pavements. However, the optimum technology determined (visual inspection, HWD, and DCP) still presented limitations in terms of availability and speed of data acquisition, requiring prioritization of the work. A risk analysis was then completed, establishing work prioritization within each airfield and providing a prioritization of all U.S. Navy and Marine Corps airfield pavements. An Interim Policy and Technical Guidance (IP&TG) was issued on 23 March 2000 to establish the developed void detection methodology. This is now included as an appendix in Department of Defense Unified Facilities Criteria UFC 3-260-03 and routinely applied at all 70 major Navy and Marine Corps airfields. This paper summarizes the methodology used and presents some recent field cases.
         Luis Javier Malvar, U.S. Navy Engineering Service Center, luis.malvar@navy.mil

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    10-3554 - Stiffness Characterization of Reinforced Asphalt Pavement Structures Built over Soft Organic Soils
    Session 644
    Many existing roadways in Florida are built over thick organic and peat layers which cause excessive pavement distress in the form of cracking, distortion, rutting and differential settlement. This paper presents a case study in the use of a variety of geosynthetic and steel mesh reinforcing products embedded in the asphalt overlay of SR15/US98 in southeast Florida in an effort to extend the useful life of the pavement structure. A total of 24 test sections (each 152 m long) were constructed which included 8 control sections, and 16 reinforced asphalt sections containing Glasgrid, PetroGrid, PaveTrac and Asphalt Rubber Membrane Interlayer (ARMI), at 2 different test locations representing significantly different subsoil characteristics. Prior to the rehabilitation project, series of Falling Weight Deflectometer (FWD) tests were conducted at every 15.2 m (50 feet) along the proposed test section alignment for evaluating the existing pavement capacity, and statistically determining the site variability among the test sections. Six months after the reconstruction project, FWD tests were repeated at the same locations for characterizing the performance improvements of the test sections. Though FWD tests constituted the primary evaluation technique, conventional backcalculation technique was impractical as thickness of the asphalt layer was far from uniform for having added more and more material over the years assuring a uniform pavement profile. Accordingly, FWD test results were directly employed to quantify the stiffness properties of the composite pavement based on load-deflection data thus evaluating the relative performance of the reinforced pavement sections. Based on statistical analysis of the data, it was found that the stiffness of the reinforced sections were consistently higher than the control sections, owing primarily to the reinforcements. Also, a slight trend was observed from this early age data indicating an expected relationship between the performance of the test sections and the site geotechnical characteristics.
         Khaled  Sobhan, Florida Atlantic University, ksobhan@fau.edu
         K. P. George, University of Mississippi
         Daniel  Pohly, Florida Atlantic University
         Hesham A. Ali, Florida International University

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    10-3582 - Analysis Method for Drilled Shaft-Stabilized Slopes Using Arching Concept
    Session 236
    The use of drilled shafts to stabilize an unstable slope or to fix a failed slope has gained popularity in highway applications mainly due to the fact that it is a structural fix that does not require additional right of way, as compared to change in slope geometry (adding berms to the toe of the slope) or other methods of stabilization. The main purpose of this paper is to introduce an analysis method for determining the FS of a drilled shaft/slope system and for determining the earth thrust on the drilled shafts for structural design of the drilled shafts. The concept of the analysis is cast in the limiting equilibrium approach via. method of slices, while incorporating the drilled shafts induced arching effects as the soil mass moves down-slope and around the drilled shafts. The mathematical equations based on the limiting equilibrium calculation, together with the load transfer factor for accounting for the drilled shafts induced arching effects, is presented in this paper. The 3-dimensional FEM parametric study using ABAQUS program is used to derive the regression based semi-empirical equations for quantifying the arching effect through the load transfer factor. A UASLOPE computer program is written to incorporate the above mentioned algorithms for applications to real cases. A case study of a fully instrumented and monitored slope stabilization project, ATH-124, in Ohio, is presented. The analysis of the stabilized slope at the ATH-124 project site using FEM and the computer code UA Slope are presented, together with field monitored data. Based on field monitoring data and the comparison between the finite element analysis results and the computer code UA slope for the global factor of safety and shaft force , the suggested analysis and design approach appears to be reasonable.
         Robert  Liang, University of Akron, rliang@uakron.edu
         Wassel  Al Bodour, University of Akron
         Mohammad  Yamin, University of Akron
         Arash  Erfani joorabchi, University of Akron

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    10-3825 - Variability in Resilient Modulus of Reclaimed Asphalt Pavement as Base Layer and Its Impact on Flexible Pavement Performance
    Session 243
    The use of reclaimed asphalt pavement (RAP) as a base layer is gaining popularity, but there are gaps in the literature about the material performance. One problem that has not been well investigated is the variability in the resilient modulus (MR) of RAP as a base layer compared to typical granular material, and the impact of this variability on pavement performance. In addition to the expected variability in MR of the base layer resulting from the use of aggregates that have different qualities, the process of selecting one MR value has its own variability. This paper investigates the effect of three sources of variability in determining the base layer resilient modulus in the laboratory for RAP compared to granular material. The first source that was considered is the variability in the material and sample preparation for the MR testing. The second source of variability is the constitutive model used to predict the resilient modulus. The third source is the state of stress used to predict the base layer modulus. The study compares the variability of MR of RAP to MR of unbound granular materials based on actual testing results. The impact of MR variability for RAP compared to granular material on the flexible pavement distresses is investigated using the Mechanistic-Empirical Pavement Design Guide (MEPDG).
         Mohamed Ibrahim El-Sharkawi Attia, Zagazig University, Egypt
         Magdy  Abdelrahman, North Dakota State University, m.abdelrahman@ndsu.edu

     

    Structures

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    10-0747 - Seismic Design Recommendations for Steel Girder Bridges with Integral Abutments
    Session 680
    This paper discusses the results of the longitudinal seismic behavior of straight bridges with integral abutments. Detailed nonlinear finite element (FE) models were utilized to establish the flexibility (translational and rotational) of the steel plate girders and the abutment connections. These connection springs were incorporated in a three dimensional global model of an integral abutment bridge to study the structural dynamics characteristics, as well as the seismic load path and distribution to piles, soil, girder elements. A procedure was demonstrated to determine embedment length of steel girders in the abutment to ensure the connection rigidity and more importantly to ensure that the piles will develop their ultimate flexural capacity.
         Gokhan  Pekcan, University of Nevada, Reno, pekcan@unr.edu
         Ahmad M. Itani, University of Nevada, Reno
         Eric  Monzon, University of Nevada, Reno

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    10-0992 - Fiber-Reinforced Polymer Pile Repair Incorporating Cathodic Protection
    Session 325
    Fiber reinforced polymers (FRP) are increasingly being used for corrosion repair. As barrier elements FRP can only slow down corrosion. Cathodic protection (CP) is the only proven method for stopping electro-chemical corrosion of steel. This paper describes a new method for repairing corrosion damage in which a sacrificial cathodic protection system is incorporated within a FRP repair. The system was implemented in a demonstration project in which corroding piles supporting the Friendship Trail Bridge, Tampa Bay were repaired. The repaired piles were instrumented so that the performance of the CP system could be assessed. Results indicate that the CP system is effective in protecting the reinforcing steel. It also shows that corrosion rates are lower in FRP wrapped piles. This implies longer lives for the sacrificial anodes.
         Rajan  Sen, University of South Florida, sen@eng.usf.edu

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    10-1599 - Flexural Behavior and Design with High-Strength Bars and Bars Without a Well-Defined Yield Point
    Session 274
    An ongoing project, the National Cooperative Highway Research Program (NCHRP) Project 12-77, was formed to evaluate and prepare appropriate revisions to the AASHTO LRFD Bridge Design Specifications and the AASHTO LRFD Bridge Construction Specifications in reference to high-strength reinforcement as well as other types of steel not having a well-defined yield plateau. Analytical and experimental studies are being conducted to identify and overcome deficiencies in the existing knowledge base. The focus of this paper is on behavior and design of flexural members reinforced with high-strength reinforcement (ASTM A1035) as well as other types of steel without well-defined yield plateaus. Analytical formulations and experimental testing of full-scale beams are reported. For members with most commonly encountered amounts of longitudinal reinforcement ratio, flexural capacity can be established by using well-established strain compatibility analysis procedures in which the steel stress-strain behavior is idealized as being elastic-perfectly plastic with the yield point taken as the stress at strain equal to 0.0035 or 0.005. For beams with reinforcement ratios larger than 3% and concrete strength exceeding 69 MPa (10 ksi), the use of stress corresponding to strain equal to 0.0035 is conservative and recommended. For high-strength reinforcement, the current strain limits of 0.002 and 0.005 should be changed to 0.004 and 0.008, respectively for tension-controlled and compression-controlled members. Beams reinforced with high-strength ASTM A1035 bars exhibit adequate ductility and do not suggest any unexpected response characteristics.
         Bahram M Shahrooz, University of Cincinnati, bahram.shahrooz@uc.edu
         Jonathan  Reis, University of Cincinnati
         Elizabeth  Wells, University of Cincinnati
         Richard Alan Miller, University of Cincinnati
         Kent  Harries, University of Pittsburgh
         Henry G. Russell, Henry G. Russell, Inc.

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    10-1653 - Characterization of Two-Layer Soil System Using a Light Weight Deflectometer with Radial Sensors
    Session 344
    Non-destructive tests to estimate stiffness modulus, such as the light weight deflectometer (LWD), have experienced increased popularity, but very little research has been performed to evaluate the LWD with radial sensors. Results are presented from LWD testing with radial sensors that measured the deflection bowl on one- and two-layer field test beds consisting of unbound materials. LWD testing produced a measureable deflection bowl on medium stiffness granular materials to a radial sensor spacing of 750 mm (30 in). When limited to a stiff over soft layered system, the LWD with radial sensors demonstrated the ability to accurately backcalculate layered moduli. Backcalculated moduli closely matched laboratory determined moduli from triaxial testing at a similar stress state as in the field. The measurement depth for the LWD with radial sensors was found to be 1.8 times plate diameter versus the measurement depth of conventional LWD testing of 1.0 to 1.5 times plate diameter. The LWD with radial sensors was able to measure deeper than conventional LWD testing because the radial geophones measure vertical surface deflections caused almost entirely by strains in deeper material. As compared to other configurations, the 300 and 600 mm (12 and 24 in) radial sensor configuration is recommended for unbound materials because it produced the most accurate moduli backcalculation results and captures deflections critical to the backcalculation process.
         Christopher T. Senseney, Colorado School of Mines, csensene@mines.edu
         Michael A. Mooney, Colorado School of Mines

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    10-1741 - Failure and Repair of Deck Closure Pour on Interstate 81
    Session 443
    On April 6, 2009 a 3’ x 3’ section of a closure pour in a reinforced concrete deck on Interstate 81 punched through. The deck was cast in 1992 during a deck replacement project in which each lane and shoulder of the deck was replaced while traffic used the adjacent lane. The center closure pour connected the two new deck placements. An examination of the failed section revealed that a total of eighteen #5 rebars were sheared to create the hole in the deck. The epoxy coated rebars had sustained section loss due to corrosion caused by water and chlorides leaking through the construction joint and a transverse crack. Repair consisted of removing an 8-ft wide section of the deck that spanned between the steel beams along each side of the closure pour over the entire length of the bridge, forming the opening, placing MMFX2 reinforcement that spanned between the beams, and placing expansive bridge deck concrete prepared with Type K cement. Four slabs removed from the closure pour area were delivered to the Virginia Tech Structures and Materials Research Laboratory for evaluation. Evaluation methods included chloride contents, concrete resistivities, corrosion potentials and currents and the electrical indication of the resistance of concrete to chloride penetration. This paper presents the results from the evaluation of the closure pour failure and the deck repair.
         Michael M. Sprinkel, Virginia Center for Transportation Innovation and Research, michael.sprinkel@vdot.virginia.gov
         Richard E. Weyers, Virginia Polytechnic Institute and State University

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    10-2214 - Use of Corrosion-Resistant Reinforcement as a Sustainable Technology for Bridge Deck Construction
    Session 325
    As part of the Innovative Bridge Research and Construction Program (IBRCP), this study used the full-scale construction project of the Route 123 Bridge over the Occoquan River in Northern Virginia to identify differences in the installation practices and comprehensive placement costs of epoxy-coated reinforcing steel (ECR) and corrosion-resistant reinforcing steel (CRR), specifically MMFX 2. Two bridge decks were constructed separately with a raised median covering the longitudinal joint between them. The southbound and northbound decks were reinforced with ECR and MMFX 2 respectively. Inclusion of the labor and unanticipated costs directly related to the respective deck reinforcement raised the in-place cost of MMFX 2 from $0.78/lb to $0.87/lb and that of ECR from $0.51/lb to $0.90/lb. Sealing of cracks in the ECR side was determined to be directly related to deck construction, thus these unanticipated costs were included in the $0.90/lb figure. Including the indirect costs of the sealing operations, however, more than quadrupled the final cost of ECR over its initial unit bid price. The final in-place estimated cost of ECR, in the range of $2.34/lb to $2.90/lb, reversed the cost advantage of ECR over MMFX 2 that existed in the planning stage. In the expectation of a future stream of similar maintenance operations and the costs imposed on the public during such operations, the results of this study demonstrate that CRR is the more sustainable choice for deck reinforcement steel and highlights the need to be mindful of hidden costs when comparing reinforcement materials on a cost basis.
         Audrey K. Moruza, Virginia Center for Transportation Innovation and Research, Audrey.Moruza@VDOT.Virginia.gov
         Stephen R. Sharp, Virginia Center for Transportation Innovation and Research

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    10-2267 - Implementation of Quality Management of Base Materials with Seismic Methods: Case Study in Texas
    Session 344
    Existing practices for field quality management of unbound layers (base, subbase and subgrade) rely on the adequacy of parameters such as density and moisture content. However, increasingly accepted mechanistic-empirical pavement design is primarily based on the strength and stiffness of the pavement layers. Therefore, methods to measure the modulus or stiffness of soil layers in the field shortly after construction may lead to a more reliable implementation of the design process. Modulus-based quality management methods may be more beneficial than traditional techniques because they test materials in their natural state. Nondestructive testing (NDT) methods allow for obtaining modulus of pavement layers in a rapid way. Seismic methods are one example of available methods that can be used to measure the modulus of finished unbound layers. Seismic methods are particularly attractive because they yield the same parameter (low-strain modulus) for the lab and field tests and do not require any backcalculation process. Performing the simplified seismic laboratory and field tests along with more traditional tests may lead to a smooth integration of design procedures along with pavement evaluation. In this paper, an overall approach that integrates design, laboratory and field quality management processes is presented. To evaluate the proposed method, a case study was investigated to corroborate its usefulness and convenience.
         Manuel  Celaya, University of Texas, El Paso, mcelaya@aidpe.com
         Soheil  Nazarian, University of Texas, El Paso
         Deren  Yuan, University of Texas, El Paso

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    10-3951 - Feasibility of Stainless Steel as Bridge Deck Reinforcement Material: Sensitivity of Life-Cycle Evaluation to Key Analysis Variables
    Session 325
    Bridge designers strive to implement cost-effective designs that yield minimal rehabilitation frequency and intensity over the facility life and hence least life-cycle preservation cost to the agency and agencies. As such, the bridge engineering community seeks new materials, configurations, and other design elements to meet this objective. The efficacy of new materials can be influenced by the context under which they are used. This paper discusses the potential of stainless steel as a bridge deck reinforcement material and analyzes the sensitivity of the cost-effectiveness of this material to key input parameters such as interest rate, user cost weight, traffic volume. The superior reinforcement material alternative was determined on the basis of the criteria that include agency cost, user cost, and material service life. Using data from a mid-western state in the United States, this paper carried out sensitivity analysis and showed that using stainless steel as reinforcement material for the bridge deck, under a majority of the analysis scenarios, yields significantly higher initial costs but drastically reduced costs over the bridge life cycle, and thus is more cost-effective over the long term. In harsher environments where bridges are more vulnerable to corrosion, the relative benefits of stainless steel are expected to be even higher.
         Amanda  Cope, Purdue University
         Samuel  Labi, Purdue University, labi@purdue.edu

     

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    10-0471 - Agency-Initiated Bus Noise Reduction for Los Angeles Metro Orange Line
    Session 523
    This paper presents noise control efforts of the Los Angeles County Metro Orange Line, one of the first bus rapid transit (BRT) systems in the U.S. through residential areas. The Orange Line is a 14-mile (22.5 km) dedicated BRT corridor in the San Fernando Valley in Los Angeles County that utilizes 60-foot (18.3 m), articulated vehicles powered by compressed natural gas engines. Noise control efforts included noise mitigation design features, establishing noise emission values of the buses, modeling of the operational noise to determine location where residual impacts occur, establishing background noise levels, monitoring operational noise levels, mitigation of residual noise impacts, and retrofitting the fleet with new mufflers. The paper discusses the results of an agencies commitment to resolving community environmental noise issues and provides guidance regarding noise modeling and noise specification of city buses.
         Ramon  Nugent, Acentech Inc., rnugent@acentech.com
         McDuffee  Mathew, Acentech Inc.
         Carl Peter Ripaldi, Los Angeles County Metropolitan Transportation Authority
         Michael  Chang, Los Angeles County Metropolitan Transportation Authority

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    10-3437 - Impact of Carsharing on Household Vehicle Holdings: Results from North American Shared-Use Vehicle Survey
    Session 313
    Carsharing has grown considerably in North America during the past decade and has flourished within metropolitan regions across the United States and Canada. The result has been a new transportation landscape, which offers urban residents an alternative to automobility without car ownership. As carsharing has expanded, there has been a growing demand to understand its environmental impacts. This paper presents the results of a North American carsharing member (N = 6,281) survey. The authors establish a “before-and-after” analytical design with a specific focus on carsharing’s impacts on household vehicle holdings and the aggregate vehicle population. The results show that carsharing members reduce their vehicle holdings to a degree that is statistically significant. The average vehicles per household of the sample drops from 0.47 to 0.24. Most of this shift constitutes one-car households becoming carless. The average fuel economy of vehicles shed by carsharing households is on average 10 miles per gallon (mpg)/16 kilometers per gallon (kmpg) less than the carsharing vehicle most often used by respondents. The median age of vehicles shed by carsharing households is 11 years, but the distribution covers a considerable range. A sensitivity analysis of the sample with respect to the membership population suggests that carsharing has taken between 75,000 to 94,000 vehicles off the road, which equates to 9 to 12 vehicles (including shed and postponed auto purchases) for each carsharing vehicle.
         Elliot W. Martin, University of California, Berkeley, elliot@berkeley.edu
         Susan A. Shaheen, University of California, Berkeley
         Jeffrey R. Lidicker, University of California, Berkeley

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    10-4092 - Mitigating Excessive Idling of Transit Buses
    Session 523
    In recent years, much media attention has been paid to research developments related to three types of diesel vehicles: School buses, long-haul trucks and transit buses. Transit bus emissions studies get attention often because the public wants to know if transit agencies are spending public dollars efficiently and with concern for public health. The public health and environmental effects of transit bus idling and strategies to mitigate idling practices need to be understood. Most transit bus idling is considered “non-discretionary,” occurring while a bus is stuck in traffic or making a stop along its route. There are, however, some scenarios in which transit buses idle unnecessarily, and despite the fact that many solutions exist to limit idling from these buses, these solutions have not garnered much interest from transit agencies, researchers or lawmakers. This paper will review the causes and effects of transit bus idling, and will examine the potential costs and benefits of employing idling-reduction technologies and policies on the bus fleet of a large metropolitan transit agency in the Midwest to limit fuel consumption and emissions. The paper is organized as follows: Economic, environmental and health effects of diesel emissions are discussed in the background section, as well as current anti-idling public policy. The research methodology is described, and causes of excessive bus idling at the Chicago Transit Authority are discussed as well as potential solutions. Idling-reduction technologies are examined to determine which provides the greatest economic and environmental benefit for the lowest cost. The conclusion presents specific recommendations for the Chicago Transit Authority.
         Emily  Ziring, University of Illinois, Chicago
         P. S. Sriraj, University of Illinois, Chicago, sriraj@uic.edu