大粒径沥青碎石加铺层结构反射裂缝调查及应力分析

采用大粗粒径沥青碎石作为裂缝缓解层，利用大粒径沥青碎石的多空隙结构阻断裂缝尖端的扩展路径，消散及吸收由交通荷载及环境温度变化所产生的应力及应变，减小接缝处加铺层的应力集中现象．采用三维有限元法对设置普通沥青混凝土与大粒径沥青碎石两种类型裂缝缓解层的加铺结构进行力学对比分析可知，后者的荷载应力、温度应力及耦合应力均小于前者的应力值．通过加铺层试验路观测与理论计算分析表明，大粒径沥青碎石裂缝缓解层可有效地防止或减缓水泥混凝土路面沥青加铺层的反射裂缝．

Investigation of reflective cracking and stress analysis for overlay structure with large-size asphalt macadam

With the large-size asphalt macadam is used as cracking relief layer, a great deal of void in the extra large-size asphalt macadam can obstruct the extending path of crack tip, dissipate or absorb the stress and strain of vehicle load and the environmental temperature variety, reduce the stress centralization of asphalt overlay at joint of cement concrete pavement. The 3-D finite element method is used to analyze the cracking relief layer of asphalt concrete and extra large-size asphalt macadam, the load stress, thermal stress and coupling stress of the latter are less than the former. The investigations of testing highway and results of theoretic calculation indicate that the extra large-size asphalt macadam layer can prevents asphalt overlay from cracking effectively.