Publication Number: FHWA-RD-02-008
Date: March 2002

New Asphalt Temperature Prediction Standard Adopted

A new asphalt pavement temperature prediction standard developed through the Long-Term Pavement Performance (LTPP) program has been adopted by the American Association of State Highway and Transportation Officials (AASHTO) Subcommittee on Materials. The standard provides an improved method for predicting the temperature within the asphalt layers of a pavement, using readily available data such as the infrared pavement surface temperature collected during routine deflection testing, the average air temperature the day before testing, and the time of testing.

Being able to accurately predict the pavement temperature and its effect on the deflection testing is important, as deflection testing is used to evaluate such pavement characteristics as axle or vehicle load capacity, structural life, and uniformity. To effectively analyze the data collected, the deflection results must be adjusted to account for both seasonal and temperature variations. Along with the temperature prediction method, the LTPP program has developed procedures for adjusting the deflection data for temperature. Applying these procedures allows data collected under varying temperature conditions to be compared and used interchangeably.

The new AASHTO standard, entitled Prediction of Asphalt-Bound Pavement Layer Temperatures (No. T317-02), will be published in the 22nd edition of AASHTO's Standard Specifications for Transportation Materials and Methods of Sampling and Testing. The new edition is due out in August 2002. For more information, contact the AASHTO Publications Order Department at 1-800-231-3475 (Web: www.transportation.org/publications/bookstore.nsf). The temperature prediction and data adjustment procedures developed by the LTPP program can be found in the report, Temperature Predictions and Adjustment Factors for Asphalt Pavements (Publication No. FHWA-RD-98-085). The report is available on the LTPP Web site at https://www.fhwa.dot.gov/pavement/pub_listing.cfm?areas=LTPP. It can also be obtained from the Federal Highway Administration (FHWA) Research and Technology Report Center at 301-577-0818 (fax: 301-577-1421).

For more information, contact Cheryl Richter at FHWA, 202-493-3148 (email: cheryl.richter@fhwa.dot.gov).

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