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The National Academies

NCHRP 09-22 [Completed]

Beta Testing and Validation of HMA PRS

  Project Data
Funds: $1,500,000
Research Agency: Fugro Consultants, Inc.
Principal Investigator: James Moulthrop, Matthew Witczak
Effective Date: 10/3/2000
Completion Date: 6/30/2011
Comments: The project final report is available as NCHRP Report 704.

NCHRP Project 9-22 began in 2000 with the goal of advancing the HMA PRS software (HMA Spec) developed in the WesTrack project to implementation. However, the capabilities of the WesTrack PRS software proved too limited for general use across the United States. The project then evaluated the possibility of directly adapting the Mechanistic-Empirical Pavement Design Guide (MEPDG) software to use as an HMA PRS but this approach proved too complex and was superseded by work to base the HMA PRS on the spreadsheet solutions of the MEPDG originally developed in NCHRP Project 9-19 as specification criteria for the simple performance tests for permanent deformation and fatigue cracking. This final version of the HMA PRS was named the Quality-Related Specification Software (QRSS).

The QRSS is a stand-alone program that calculates the predicted performance of an HMA pavement from the volumetric and materials properties of the as-designed HMA and compares it with that of the as-built pavement calculated from the contractor's lot or sub-lot quality control data. The calculated differences for the permanent deformation, fatigue cracking, low-temperature cracking, and IRI determine pay factors for each lot or sub-lot. The performance predictions are project-specific; the QRSS accounts for the climate, traffic, pavement structure, and desired or expected service life. Further, the predictions are probabilistic; they are calculated through a Monte Carlo procedure that uses historical standard deviations of the input properties in order to account for construction and testing variabilities when assigning risk between the owner agency and the contractor.

The objective of this project was to develop, test, and evaluate the QRSS.

The project final report, including Appendix E, is available as NCHRP Report 704, A Performance-Related Specification for Hot Mix Asphalt. The following appendixes to NCHRP Report 704 are also available for download:
• APPENDIX A: Raw Data for Permanent Deformation Model Analysis
• APPENDIX B: Raw Data for Fatigue Cracking Model Analysis
• APPENDIX C: Summary of Results for Level 3 Creep Compliance Predictive Equations
• APPENDIX D: Hardening Ratio Database

 


A CD-ROM containing a new December 2011 QRSS Version 1.0.1.0 is available as an ISO image which can be downloaded and burned to a blank CD. (Here is some help on burning an ISO image.) This new version has been extensive debugged. Instructions for installing the QRSS on computers running Windows XP and Vista and Windows 7 are also available here, as is a zip file containing the necessary climatic files for locations in the United States.


Dr. Myung Jeong developed a complementary program to the QRSS for his Ph.D. dissertation at Arizona State University. Dr. Jeong’s program is coded as a Microsoft Excel (2007 and higher) spreadsheet named AMPT_QA_Program.xlsm. The key difference between the QRSS and the spreadsheet program is that the spreadsheet program uses measured values of E* to compute permanent deformation and fatigue cracking rather than values calculated with the Witczak Predictive Equation. Integration of the appropriate algorithms from the spreadsheet program in future versions of the QRSS may provide it with the capability to use either measured or estimated E* values depending on the specific characteristics of the project and the engineer’s wishes.

The spreadsheet program, a manual of practice, and a readme file can be downloaded at following links: http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP09-22_AMPT_QA_Program.zip; http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP09-22_AMPT_QA_SoftwareManualOfPractice.pdf; and http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP09-22_ReadMe-AMPT_QA_Program.docx

This software is offered as is, without warranty or promise of support of any kind either expressed or implied. Under no circumstance will the National Academy of Sciences or the Transportation Research Board (collectively "TRB") be liable for any loss or damage caused by the installation or operation of this product. TRB makes no representation or warranty of any kind, expressed or implied, in fact or in law, including without limitation, the warranty of merchantability or the warranty of fitness for a particular purpose, and shall not in any case be liable for any consequential or special damages.


 

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