Study On Asphalt Overlay Structure Of Old Cement Concrete Pavement In Changhai County

Changhai County locate in the island,due to the adverse conditions of the island,the current service road is still cement concrete pavement.In the effect of driving load and external environmental factors,the performance of cement concrete pavement is gradually decayed,and the old cement concrete pavement can be repaired by overlaying the asphalt overlay.The residual strength of the old cement concrete pavement can be effectively utilized to improve Performance of pavement.In this paper,the asphalt overlay in Changhai County,the feasibility of the following studies:(1)The climate characteristics of Changhai County were investigated,and Changhai County was defined as water stable and low temperature anti-cracking area.The anti-water damage and low temperature anti-cracking performance were mainly considered in the asphalt overlay.The main disease of the old road for the bottom of the vacant,the wrong platform and panel cracks.(2)The finite element software ABAQUS was used to build the 3D model.The influence of low void and misplaced of old cement concrete pavement on the overlay structure was analyzed.The internal and external parameters of the overlay structure were studied qualitatively.Load coupling effect on the structure of the overlay,asphalt surface layer design to provide a reference index.(3)Based on the research and engineering practice of traditional asphalt concrete cover materials,a new type of cover material is proposed.Micro cover is a kind of high polymer material with good anti-invasion performance and long use.The results are compared with those of the asphalt overlay.The results are compared with the result of the asphalt overlay structure by ABAQUS finite element software.(4)The asphalt layer structure on the old cement concrete pavement is easy to produce reflection crack.Based on the climatic conditions of Changhai County,the fracture stress intensity factor of asphalt overlay under vehicle load and temperature is analyzed by fracture mechanics and finite element method.The effect of the parameter variation of asphalt overlay thickness,modulus and temperature drop on the stress intensity factor of the overburden cracks was studied.The effect of the modulus and thickness of the asphalt overlay on the fatigue life was analyzed by generalized Paris formula.