The Research Of Combination Scheme For Ashalt Overlaon Old Cement Pavement

With the Guangzhou-Qingyuan Expressway Guanghua section expansion projectengineering practice of asphalt layer on old Concrete Pavement overlay, this paperanalyzed and summarized design methods of asphalt overlay on old Concrete Pavement,overlay thickness of Pavement Reconstruction on Guang-Qing Highway Guanghua sectionwere calculated and compared. According to traffic forecasts, road conditions, climate andother factors of the Guangzhou-Qingyuan Expressway, developed three combinations offlexible pavement overlay structure, designed three kinds of combinations on semi-flexibleasphalt overlay structure, according to various overlay layer structure, the force model ofthe different structural combinations was established.First, using finite element software ABAQUS, analyzed the stress condition ondifferent structural combinations, maximum stress contours in different locations wasobtained, the most unfavorable position of power and the extent of its effect has beenfound two original angle: longitudinal strain ε and layer bottom normal stressσ, and twonew angle: criterion of strain energy densityu dcorresponding to distortion andmaximum shearing stressτ, were compared in different structural combinations has beenstudied in-depth and compared and selected reasonable, as a result,found relatedconclusions of the overlay on the combination of the best programs,and variation ofε、σ、u d、τ in different combination scheme, proved the superiority of thecombinations of the semi-flexible asphalt overlay layer structure.Second, calculated and analyzed the internal stress of the asphalt overlay throughchanging several typical mechanical parameters of the overlay portfolio structure, obtainedthe internal stress distribution of asphalt overlay, drawed the internal stress curve ofasphalt overlay in the structure of different thickness and modulus layer, given designproposals of the structure for the overlay, obtained change laws and conclusions, finally,according to the practical engineering, the recommended structure combinations of asphaltoverlay in Guangzhou-Qingyuan Expressway extension Project was determined.