Thermal stress influence factors of asphalt overlay on cement concrete pavement cracking slab

In order to remove the reflective crack of asphalt overlay on cement concrete pavement, the paper adopted finite element method, took pavement structure as elastic layered system, founded a three-dimensional model of asphalt overlay, strengthening layer, cracked slab of cement concrete pavement and subgrade, and analyzed the influences of old cement concrete cracked size, temperature drop scope, modulus and thickness of asphalt overlay, structure strengthening layer modulus and thickness of cement concrete cracked slab on asphalt overlay thermal stress.The results indicate that the thermal stress of asphalt overlay decreases greatly with the size reduction of old cement concrete cracked slab, the influence of great temperature drop scope on overlay thermal stress is much larger than that of vehicle load, the measures such as decreasing asphalt overlay modulus and increasing asphalt overlay thickness etc can effectively improve the stress situation at cracked slab joints, and effectively prevent the reflective crack of asphalt overlay.