Evaluation of the Asphalt Mixture Performance Tester (AMPT): Utah Experience

摘要

For over 5 years, Utah Department of Transportation (UDOT) has been collecting fieldmaterial and testing it using the Asphalt Mixture Performance Tester (AMPT). Thirty four fieldmixtures were evaluated as part of this study. The mixtures were produced following UDOTstandard volumetric specifications and 2 different binder grades, PG 64-34 and PG 70-28, fromthree different suppliers.Based on the evaluation of the results obtained from these tests, it was found that theAMPT produced data with a coefficient of variation below 15%, indicating good repeatability.Mixtures prepared with different binder grades were easily separated. The dynamic modulusmaster curves of mixtures prepared using the same binder grade were essentially the sameregardless of the aggregate source (same type of mixture was used). Given these results, it wasshown that it is possible to obtain asphalt mixture level 1 MEPDG input parameters based onhistoric data, knowledge of the binder grade used and testing at only 1 temperature. The singletemperature test can be used for quality control and to verify that the mixture is of the same kindas the historical data available. This approach can significantly reduce the time and effortrequired to obtain AMPT data without any loss in performance prediction capacity; thus makingadoption of this device more appealing to state DOT’s.