Analysis on Stress in Asphalt Overlay of Old Cement Concrete Pavement

Currently,asphalt overlay is commonly applied in reconstruction of old cement concrete pavement,wherein stress-absorbing layer is set to control reflection crack.With BISAR 3.0 program,how thickness and modulus change of the stress absorbing layer affecting structural stresses in asphalt overlay in non-seam and non-crack zone on old cement concrete pavement were analyzed.The result shows that with increase of thickness of the stress-absorbing layer,not only surface deflection and bottom tensile stress of asphalt overlay continuously increase,but also tensile stress and shear stress inside the pavement increase differently;however,with increase of modulus of the stress-absorbing layer,not only the surface deflection and bottom tensile stress of asphalt overlay,but also the tensile stress and shear stress inside the pavement decrease to different extents.