Improved Discrete Element Numerical Simulation And Experiment On Low-Temperature Anti-Cracking Performance Of Asphalt Mixture Based On Pfc2d

To study the cracking law of asphalt mixtures at low temperature, an improved mesoscopic model of an asphalt mixture Marshall split specimen and three-point trabecular bending specimen were established based on the discrete element method using PFC2D. Secondly, by defining and assigning the bonding constitutive model between different particles in the asphalt mixture, the numerical simulation results of AC-13 and AC-16 continuous, dense-graded asphalt mixtures' splitting and three-point beam bending at -10 degrees C were analyzed. The experiment verified that the reliability of the numerical model described herein improved. The results showed that the two-dimensional model of an asphalt mixture based on the discrete element method can simulate the splitting and three-point beam bending test of asphalt mixtures with different gradations. Contact fracture between aggregate and asphalt mortar is the principal reason that an asphalt mixture cracks. Further, the contact between the aggregates contributes the most to the asphalt mixture's splitting strength, and the contact between the asphalt mortar and the asphalt mortar and the aggregate contributes more than 85% to the asphalt mixture's flexural tensile strength. In addition, the asphalt mixture's splitting strength and flexural tensile strength increased as the maximum nominal particle size in the asphalt mixture gradation increased. Therefore, the results of this study can provide a theoretical basis for the design of asphalt pavement materials. (C) 2021 Elsevier Ltd. All rights reserved.