Virtual Triaxial Test Simulation Based on Discrete Element Method for Shear Resistance Property Assessment of Asphalt Mixtures

Abstract In this paper, the shear resistance of asphalt mixtures, which accounts for the permanent deformation characteristics of flexible pavements to a large extent, is analyzed based on the discrete element (DE) method from a microscopic perspective. This study first considered the processes used to obtain the microscopic parameters for the DE model, which typically simulated an asphalt mixture based on its three components. Then the study employed Burger’s model to simulate the rheological behavior of asphalt sand mastics (fine aggregates, fines, and asphalt binder). A random generation algorithm was also developed to generate coarse aggregate elements in the DE model complying with the realistic gradations of asphalt mixtures. So as to more precisely model the rheological characteristics of asphalt sand mastics, the microscopic parameters of Burger’s model were calibrated via simulations of uniaxial tests in the DE model. Finally, meaningful conclusions were achieved by analyzing the simulation result and the laboratory result. The simulation result was consistent with the laboratory test result, so the use of the established DE model to evaluate the shear resistance property of asphalt mixtures is feasible.