Numerical Analysis Of Mechanic Effects Of Asphalt Isolation Layer For Cement Concrete Pavements

The asphalt isolation layers are usually adopted to prevent the rainwater scour of subbase in the design of cement concrete pavements. It has been proven that the asphalt isolation layer for cement concrete pavements is helpful to prolong pavement service life and reduce the incidence of corresponding diseases in the rainy areas. Therefore, it is necessary to understand the mechanical effect of asphalt isolation layer for cement concrete pavements. This paper established the three dimensional finite element models for cement concrete pavements, calculated the stresses and displacements of pavement structures under static loads, temperature feilds and moving loads using the commercial software ABAQUS, and analyzed the machanical effects of different thickness and modulus of asphalt isolation layer.(1) From the mechanical analysis under static loads, the maximum stress of cement pavements is largely influenced by the thickness and modulus of asphalt isolation layers. The asphalt isolation layers can effectively improve the mechanical condition of cement concrete pavements.(2) From the mechanical analysis under temperature feilds, the maximum stress of cement pavements is slightly influenced by the thickness and modulus of asphalt isolation layers. The asphalt isolation layers can tinily improve the temperature stress of cement concrete pavements. Although the maximum stress of asphalt isolation layers is greatly influenced by the thickness of asphalt isolation layers, in fact, the low temperature stress will not impact on the asphalt isolation layers.(3) From the coupling analysis under static loads and temperature feilds, the maximum stress of cement pavements is slightly influenced by the thickness and modulus of asphalt isolation layers. The asphalt isolation layers can tinily improve the coupling stress of cement concrete pavements. Although the maximum stress of asphalt isolation layers is greatly influenced by the thickness of asphalt isolation layers, in fact, the low coupling stress will not impact on the asphalt isolation layers.(4) From the mechanical analysis under moving loads, the maximum stresses of cement concrete pavement and cement stablized base are largely influenced with/without the asphalt isolation layers. In addition, the dynamic responses of concrete pavements are remarkedly influenced by the vehicle moving speed, thickness and modulus of the asphalt isolation layers.