Numerical And Experimental Studies For Multi-Cracks Of Asphalt Pavement With Semi-Rigid Basement Asphalt

Cracking has become a serious problem in the semi-rigid base asphalt pavements construction. It has an important theoretical and practical significance to study the semi-rigid base asphalt pavements with multi-cracks under thermal loads and vertical traffic loads. The mechanics behavior of the asphalt pavements and the crack propogation are studied in this thesis. It includes:(1) The present research situation and the tendency of developments in relevant fields are summarized. The general Maxwell model is used for simulating the asphalt mixture viscoelastic property.(2) The thermal response of the asphalt pavement with multi-cracks under temperature load is studied by FEM simulation. First, based on the theory of heat transmission, the road temperature filed and stress filed are caculated. Then, the effects of crack spacing to the stress intensity factors and the stress of the crack tip are analyzed.(3) Combining the dynamics and fracture mechanics, the dynamic response of the asphalt pavement with multi-cracks under vertical traffic load is studied by modal analysis and transient analysis. The effects of crack spacing to the stress intensity factors and the stress of the crack tip are analyzed.(4) Based on one of the road construction projects in Henan, the cracking propagation analysis of asphalt pavement with multi-cracks under vertical load is studied through FEM simulation. The influence of layer modulus, layer thickness and the relative position between cracks to the propagation are studied. A series of tests have been performed to simulate the crack propagation. The numerical results have been compared with the experimental results and show good agreements.