Simulation of Creep Damage of Asphalt Mixture Based on Discrete Element Method

This paper proposes a creative approach for conducting discrete element simulation of creep tests to simulate the mechanical behavior of asphalt mixture and analyze the mechanism of creep damage by virtual tests. Based on the discrete element method (DEM), the creative approach named the aggregate template method was presented to generate the irregular polyhedron of coarse aggregate by 3DsMax and PFC3D. The asphalt mortar was then replaced by spherical particles and by PFC3D. Based on the above preparation, the uniaxial creep tests were simulated by PFC3D and verified by actual tests to illuminate the micromechanical behavior and the creep damage of asphalt mixtures. The test results indicate that the fracture of force chains is consistent with the damage of real samples. The load is used to damage the sample by breaking the bond between the particles and the temperature is used to soften the asphalt mortar particles to damage the sample. The attenuation rate of the cohesive force of particles at the boundary of the sample is obviously larger than that at the center in the process of loading. It was verified that the aggregate template method in DEM is a reasonable approach for studying the creep test of asphalt mixtures by error analysis.