基于脆性涂层法的沥青路面反射裂缝试验研究

Experimental Study of Reflection Crack of Asphalt Pavement Based on the Method of Brittle Coat

采用脆性涂层法研究沥青路面的反射裂缝,并将试验结果与有限元计算结果进行了比较。结果表明,脆性涂层的裂纹围绕着碎石与沥青胶砂的界面发展,在该界面位置拉应力高度集中;路面基层的裂缝顶部附近发生应力集中,应力集中区的碎石与沥青胶砂界面是最容易萌发裂纹引发裂缝扩展破坏的部位;脆性涂层的裂纹分布总体是从车轮作用面向四周扩散,并围绕大粒径碎石扩展,弯拉型反射裂缝与剪切型反射裂缝涂层裂纹分布明显不同;大粒径的沥青混合料抗反射裂缝能力较强。

The method of brittle coat is used to study reflective crack of asphalt pavement, comparing the experimental results with that gotten by FEM. The laboratory results showed that the crack of brittle coat propagated around macadam, stress concentration occurred at the interface between macadam and asphalt mixture. The results suggested that pulling stress concentration occurred around the lower layer cracking, interface between macadam and asphalt mixture in the region of stress concentration were most dangerous in pavement.As a whole, brittle coat flaw developed radiately around the wheel track area, while flaw distribution of reflection crack of bend and tension type was different from that of shearing type. It was also indicated that anti-reflection crack ability of asphalt mixture with larger macadam was better.