Case Study: Evaluation of Laboratory Test Methods to Characterize Permanent Deformation Properties of Asphalt Mixes

Abstract

Extensive laboratory tests were conducted and the results were compared to the known field performance results of Specific Pavement Studies-1 (SPS-1) sections on US281. The objective was to establish which of the available laboratory test procedures could match the observed field performance. The laboratory tests included the diametral resilient modulus, Asphalt Pavement Analyzer (APA), Hamburg Wheel Tracking Test (HWTT), Repeated Simple Shear Test at Constant Height (RSST-CH), dynamic modulus test, and repeated load permanent deformation test. It was found that both RSST-CH and repeated load permanent deformation test could differentiate the performance of different sections, and the results matched closely with the field performance. The total permanent strain was also found to be a reasonable indicator of field rutting performance. For the wheel tracking tests, the APA performed better than HWTT, but both failed to differentiate some mixes. The moduli at high temperature, including dynamic modulus, axial resilient modulus, shear resilient modulus, and E*/sin δ could screen out the bad mixes. However, those moduli (except for shear resilient modulus) failed to further differentiate the performance of mixes once they were grouped as generally “good” or “bad”.

Keywords:

• Asphalt mix
• Permanent deformation
• Modulus
• RSST-CH
• Repeated load test
• HWTT

Acknowledgements

This work could not have been completed without the assistance of Mr Stephen Sebesta, Mr Sidney Greer of Texas Transportation Institute, Dr Mike Murphy, Ms Debbie Walker of TxDOT, and Mr Carlos Peralez of Pharr District, TxDOT.