Simulation and analysis of two-point bending fatigue test of asphalt concrete based on discrete element model

In order to investigate the fatigue performance of French high modulus asphalt concrete and the correlation between Burger's parameters and fatigue life, the virtual model of asphalt mixture trapezoidal specimen in the two-point bending fatigue test was constructed in discrement element software PFC3D. The initial stiffness and the maximum stress when the specimen reached fatigue were calculated. Through the comparison between virtual and single field fatigue test curves, the credibility of simulation in DEMwas verified.Then, the impacts of top controlled displacement and Burger's parameters( E_1,E_2,η_1,η_2) on the fatigue life of the specimen were explored. The simulation results indicate that the maximum stress increases with the increase in the top controlled displacement. With the increase of E_1 and the decrease of E_2 in Burger's model, the modulus of the asphalt binder increases, and the fatigue performance of the asphalt mixture enhances. η_1 and η_2 have limited influence on fatigue life compared with E_1 and E_2.