Influences of Mesoscopic Parameters on Crack Resistance of Asphalt Mixture

The indirect tensile test was used to study the influences of asphalt binder properties, aggregate surface properties and loading conditions on asphalt mixture performance. Marshall digital specimens were generated by discrete element method (DEM) and the servo-control mechanism was used to apply the loading. The influence laws of the bond strength ratios, the bond stiffness ratios, the particle friction coefficients and the loading velocities on the stress-strain curves, the splitting strengths, the coordination numbers and the micro-cracks were analyzed. The results show that the variation of the splitting strengths, the coordination numbers, and the micro-cracks caused by the bond strength ratios are the greatest, the coefficients of variation of the splitting strengths and the coordination numbers are 56.9% and 5.9%, respectively, and the difference between the most number of micro-cracks and the fewest number of micro-cracks is 43. However, the variation of the splitting strengths, the coordination numbers, and the micro-cracks caused by the loading velocities are the smallest, the coefficients of variation of splitting strengths and coordination numbers are 2.3% and 1.7%, respectively, and the difference of the number of micro-cracks is only 1. The results verify that the contribution of asphalt binder properties to the crack resistance of asphalt mixture is dominant from the mesoscopic viewpoint.