大粒径沥青混合料基层缓解反射裂缝应力分析

Reflection Cracking Resistance Stress Analysis of Large Stone Asphalt Mixtures Base in Asphalt Pavement

结合沪蓉西高速公路宜长试验段铺筑大粒径沥青混合料基层试验路的实例,采用三维有限元法对几种基层的路面结构进行力学计算,结果表明大粒径沥青混合料LSAM-30和ATPB-30防裂效果较为理想.对混合料性能参数与计算应力的对比研究表明:温度应力是引起反射裂缝的主要原因;公称最大粒径、粗骨料含量和粉-砂-胶粘结料的含量是影响密实型混合料热物理性能的关键因素;单从降低路面层温度梯度的角度,ATPB-30空隙型结构不是一种有效的材料,但其较强的柔性性能仍使其具有最好的防裂能力.

With the large stone asphalt mixture is used as flexible base on the Yichang-Changyang test section of the west expressway of Shanghai-Chengdu,the 3-D finite element method is used to calculate the stress of pavements for several flexible bases.The results indicate that the LSAM-30 and ATPB-30 are more effective.The comparason conclusions are obtained:the temperature stress is the prime reason to generate the reflecting cracks;the maximum nominal particle-size,content of coarse aggregate and asphalt-breeze-sand binder are the key indexes that influence the thermal performance of the closed asphalt mixture.As a kind of void type mixture,ATPB-30 is not an effective material if it's only judging by the reduction of the temperature gradient of pavement layer,but its super flexibility performance will still make it have the best performance of defending reflecting cracks.