大跨径钢桥面沥青混凝土铺装层裂缝机理分析

Analysis of Mechanism of Cracks in Asphalt Concrete Pavement of Long Span Steel Bridge Deck

裂缝类病害是影响钢桥面铺装使用性能的主要病害之一。根据国内多座大跨径钢桥沥青混凝土铺装病害的调查结果,把铺装裂缝类病害分为两类,即第一类裂缝和第二类裂缝。同时,采用三维有限元方法,对不同类型裂缝产生的机理进行了分析。第一类裂缝一般为Top-Down型裂缝,产生的原因与正交异性钢桥面板的构造密切相关;第二类裂缝一般为Down-Top型裂缝,其出现的原因与层间不完全连续或者防水粘结层失效有关。第一类裂缝一般出现在铺装层使用早期,继而成为第二类裂缝或者其他类型病害的诱因,因此要重视第一类裂缝的预防以及维修。如果桥面铺装出现大面积第二类裂缝,则表明铺装层已经进入使用末期。

Crack is one of the distresses which influence the property of pavement on steel deck. According to investigation of asphalt concrete pavement of long span steel bridge deck in China, cracks of steel deck pavement are divided into two types： the First-Type Crack （FTC） and the Second-Type Crack （STC）. FTC is Top-Down crack, and has close relationship with the structure of orthotropic steel deck; STC is Down-Top crack, and whose appearance is due to discontinuous interlayer or inefficacy of waterproof and adhesion layer; most of FTC may emerge at the beginning of pavement life and then become the inducement of STC or other distresses. Therefore, more attention should be paid on the maintenance of FTC. If there are huge numbers of STC, which means the steel deck pavement may come to the end of its life.