Laboratory evaluation of cracking in asphalt concrete

Cracking is one of the major distresses in asphalt concrete leading to high maintenance and rehabilitation costs throughout the nations pavement infrastructure. Asphalt concrete is a three phase, heterogeneous composite consisting of aggregate, mastic, and air voids. Crack initiation, crack path and propagation are not well understood in asphalt concrete. This thesis work presents testing and analysis of cracking in semi-circular notched asphalt concrete samples in three point bending. Load and crack width data at different locations of the sample were captured in real time using Linear Variable Differential Transformers (LVDTs). Crack initiation, path, and velocity are examined with varying notch tip location, mixture type, void content, and moisture conditioning. Crack path is further examined by means of laboratory testing on the mastic and interface phases of asphalt concrete.'