旧水泥混凝土路面沥青加铺层反射裂缝力学分析

Mechanical analysis of reflection cracks in the asphalt concrete overlay on the ailing portland cement concrete pavement

文章以宁连公路南京段水泥混凝土路面改造工程为应用研究对象,通过有限元计算分析了沥青混凝土加铺层反射裂缝的受力特性,为加铺层的结构和材料设计提供依据。研究表明,随着加铺层厚度的增加,裂缝尖端应变能密度呈减小趋势,但面层厚度增大到一定程度后,减小的程度趋于缓慢。随着格栅模量的增加,裂缝尖端应变能密度值不断减小;当格栅模量超过2000MPa后,继续增加格栅模量,裂缝尖端应变能密度的减小速度变慢。当沥青稳定碎石模量在800～1000MPa时,裂缝尖端的水平应力和应变能密度较小,对加铺层反射裂缝的防止有重要作用。

Based on the study of rehabilitation of the Nanjing section of Nanjing-Lianyungang Highway, the reflection cracks of the asphalt concrete(AC) overlay on the ailing portland cement concrete(PCC) pavement are studied by the finite element method(FEM). It is shown that the strain energy density at the crack tip deduces with thickening of the asphalt overlay. The bigger the geogrid modulus, the smaller the strain energy density, but when the geogrid modulus exceeds 2 000 MPa,the strain energy density almost levels off. While the asphalt stabilized base modulus is between 800 and 1000 MPa, the stress and the strain energy density are much smaller,which are beneficial to the prevention of reflection cracks.