Size effect investigation on fracturing of asphalt concrete using the cohesive softening Discrete Element Model

ABSTRACT: Cracking in asphalt concrete is one of the major causes of structural and functional deterioration of the pavement systems, particularly in cold climates. A clustered Discrete Element Method (DEM) was applied into the investigation of size effect on fracturing of asphalt concrete based on a disk-shaped compact tension (DC(T)) test. A bilinear cohesive softening model was implemented into the DEM framework to enable simulation of crack initiation and propagation in asphalt concrete. The influence of specimen size was investigated on the fracture of asphalt concrete using the homogeneous and heterogeneous DEM fracture models. The laboratory tests were conducted for specimen sizes of asphalt concrete varying from 100 mm to 450 mm in diameter. The DEM simulations were shown to compare favorably with experimental results and Bazant’s size-effect law.