Influence of Crack Size of Old Concrete Pavement Slab on Structure Stress of Asphalt Overlay

摘要

Old concrete pavement with major damage can be reconstructed by paving the asphalt surface after cracked and stabilized with punching technique. But the cracked size is different in every country and there is no corresponding theory basis. Using 3-D finite element method, the relationships between cracked size for concrete slab and load stress, thermal stress, and coupling stress in asphalt overlay together with pressure stress on base surface were analyzed. The results show that the influence of cracked size on thermal stress and coupling stress is much greater than that of load stress. When cracked size decreases, thermal stress and coupling stress in asphalt overlay decrease rapidly. Also, the stress centralization at joints and cracks lessens evidently, while the pressure stress on base surface increases. Considering the factors synthetically, it is reasonable for the cracked size to range from 80 cm to 100 cm.