AASHTO T 321-17 PDF Download

AASHTO T 321-17 is a standard method used to determine the fatigue life of compacted asphalt mixtures when subjected to repeated flexural bending. The test involves using beam specimens, which are cut from laboratory or field-compacted asphalt mixtures. These specimens have specific dimensions of 389 mm in length, 50 mm in thickness, and 63 mm in width.

The purpose of the test is to assess the ability of the asphalt mixture to withstand repeated bending stresses over time. This is important for evaluating the long-term durability and performance of the pavement. The test measures both the fatigue life and fatigue energy of the specimens.

The procedure involves subjecting the specimens to repeated flexural bending until failure occurs. This is done by applying a four-point bending load on the specimen using a testing machine. The number of cycles required for failure, as well as the total energy absorbed during the test, are recorded and used to calculate the fatigue life and fatigue energy of the asphalt mixture.