Heterogeneous fracture simulation of asphalt mixture under SCB test with cohesive crack model

Abstract

Semi-Circular Bending (SCB) test has been used widely to investigate the cracking behaviour of asphalt mixtures, and fracture parameters can be obtained. In this paper, heterogeneous fracture modelling technology is presented to simulate crack evolution in asphalt mixtures under SCB test. Digital image processing methods are employed to generate 2-dimensional (2D) scanned images of an asphalt mixture cutting surface. Finally, a 2D heterogeneous numerical model is created for an asphalt mixture specimen, and the numerical cohesive crack model is utilised to estimate the crack resistance of the interface based on a laboratory fracture test. The inception and propagation of main macrocracks are carefully studied for the asphalt mixture. Load–displacement curves are plotted, and corresponding tensile strength and fracture strain energy density are calculated. The analysing results of numerical simulation are proved to be quite consistent with the actual experimental test results, and the reliability of the numerical model is verified.