Evaluation of Asphalt Mixture Performance Tester

For more than 5 years, the Utah Department of Transportation collected field material and tested it with the asphalt mixture performance tester (AMPT). Thirty-four field mixtures were evaluated as part of this study. The mixtures were produced according to Utah DOT standard volumetric specifications with two binder grades, Performance Grade (PG) 64-34 and PG 70-28, from three suppliers. The results of these tests showed that the AMPT produced data with a coefficient of variation below 15%, which indicates good repeatability. Mixtures prepared with different binder grades were easily separated. The dynamic modulus master curves of mixtures prepared with the same binder grade were essentially the same regardless of the aggregate source. The same type of mixture was used. These results show that it is possible to obtain input parameters for the Level 1 asphalt mixture from the Mechanistic–Empirical Pavement Design Guide on the basis of historical data, knowledge of the binder grade used, and testing at only one temperature. The single-temperature test can be used for quality control and to verify that the mixture is of the same kind as the historical data available. This approach can significantly reduce the time and effort required to obtain AMPT data without any loss in the capacity of performance prediction and thus make adoption of this device more appealing to state departments of transportation.