AASHTO T 378-17 (2021) PDF Download

The AASHTO T 378-17 (2021) standard provides a method for determining the dynamic modulus and flow number of asphalt mixtures using the Asphalt Mixture Performance Tester (AMPT). This test is specifically designed for dense- and gap-graded mixtures with nominal-maximum aggregate sizes up to 37.5 mm.

The dynamic modulus test measures the stiffness of the asphalt mixture under varying temperature and loading conditions. It helps in evaluating the performance characteristics of the mixture, such as its ability to resist deformation and cracking. The flow number test, on the other hand, determines the resistance of the asphalt mixture to permanent deformation, which is a critical parameter for pavement design and performance prediction.

The standard outlines the equipment and procedures required to conduct the tests effectively. It provides guidelines on specimen preparation, testing temperatures, and loading conditions to ensure accurate and consistent results. The standard emphasizes the importance of following proper testing procedures to obtain reliable data for use in pavement design and material selection.