Crack Propagation Simulation for Epoxy Asphalt Concrete Pavement

摘要

Crack is one of the major distresses in asphalt pavement. Although epoxy asphalt concrete demonstrates higher distress resistant ability than traditional asphalt concrete, crack initiation and propagation is also inevitable due to traffic and environmental impact. Among the three typical crack modes, the Mode I crack usually appears in epoxy asphalt concrete pavement. In this paper, the model of crack propagation in epoxy asphalt concrete pavement is proposed and simulated through finite element method in conjunction with virtual crack extension approach. The eight-node singularity element was used at the crack-tip. And the node shift/release technique is adopted for modeling propagation of the crack tip. Results show that J-integral is path-independent due to the small plastic zone around the crack tip and suitable to evaluate the fracture behavior for epoxy asphalt concrete pavement. Two inflexions on the curve of J-integral vs. crack length indicate that epoxy asphalt concrete pavement have three phases in crack initiation and propagation: crack initiation, stable crack propagation and unstable crack propagation. Finally, the equation describing the relationship between J-integral and displacement is provided in this paper.