Crack Coalescence Morphology in Asphalt Mixtures under Compressive Loading

Abstract

Cracking coalescence is the linking process of multiple cracks; the ordinary differential and partial differential equations cannot be solved at the crack coalescence positions. To solve these shortcomings, the asphalt mixture ordinary state–based peridynamic (OSB-PD) numerical model was established to simulate the crack coalescence in AC-13, AC-20, and PAC-13 asphalt mixtures. The simulated crack trajectories expressed that the wing crack, the branched crack of splitting, and diagonal cracks can coalesce to develop into a connected crack network. The random distribution crack trajectories constituted nine crack coalescence categories. The fractal dimension (FD) of crack coalescence trajectories ranged from 1.58 to 1.81; it expresses the self-similarity of crack coalescence trajectories. The crack coalescence process included (1) the crack tips moving forward, (2) the crack tips contacting each other, and (3) the crack tips connecting together.