Numerical Simulation of an Indirect Tensile Test for Asphalt Mixtures Using Discrete Element Method Software

Abstract

A three-dimensional discrete element model of an asphalt mixture is developed based on discrete element method (DEM) software to investigate the cracking mechanism of the asphalt mixture, which is validated by the results of an indirect tensile test. Then, the model is applied to study the displacement field and fracture fragment distribution in terms of the micromechanical behavior. The results indicate that the failure process can be divided into three periods, namely, elastic growth of tensile stress, rapid expansion of the cracks, and crack coalescence. The fracture fragment initially forms near the loading bar and develops gradually until coalescence. Displacement circulation arises during the loading period, and the location depends largely on the crack development. Further, parameter-sensitive analysis revealed the effects of various loading speeds, different friction coefficients, and normal-to-shear stiffness ratios of the asphalt binder on the mechanical behavior of the asphalt mixture.