环氧胶粘结刚性铺装的正交异性桥面板力学性能

Mechanical properties of orthotropic steel deck with epoxy adhesively bonded rigid pavement

摘要:

为了研究环氧胶在钢-混组合板中作为粘结层的适用性,以无配筋的超高性能混凝土作铺装层的钢桥面板为对象,采用环氧胶层连接两种材料,并考虑钢板表面处理不佳的涂胶情况,通过试验测试施涂效果欠佳的钢混胶接接头的抗剪强度,并采用该种环氧胶的施涂方式,设计制作一个足尺桥面板试件,进行受弯加载试验. 测试试件的变形、结构不同位置的应变响应以及极限承载力等,记录钢混粘结层的失效状态,并采用有限元方法对失效前的钢与混凝土之间粘结层的受力进行分析. 结果表明:该种环氧结构胶作为无配筋刚性铺装钢桥面板的粘结层时,施工操作方便；钢板表面处理效果影响到粘结层的强度；即便在钢板表面处理不佳情况下涂刷环氧胶,也能很好地保证钢板与刚性铺装层之间的可靠连接,钢结构的材料屈服先于钢与混凝土之间环氧胶层的破坏；粘结层的纵向剪应力分布不均匀,在加劲肋与顶板交界处的应力大于其他位置；采用环氧胶粘结的刚性铺装桥面板具有较好的延性和较高的承载力.

Abstract:

To study the workability of epoxy adhesive used as bonding layer in steel-concrete composite deck, a steel deck with pavement casted by unreinforced ultra-high performance concrete was chosen as research object, and an epoxy layer was introduced to connect the two materials. In the process of adhesive applying, the situation of poor pretreatment of steel surface was considered. A static test was conducted to evaluate the cohesive shear strength of the steel-concrete composite joint, and a full-scale deck specimen adopting the same adhesive bonding method was designed and tested under bending loads. The mechanical behaviors of the specimen were investigated, which include deflection of specimen, strain at different positions, and ultimate bearing capacity. The failure modes of the bonding layer were recoded, and the strain of the bonding layer before failure was analyzed by finite element method. Results show that epoxy adhesive was convenient for construction as a bonding layer between unreinforced rigid pavement and steel deck, and surface pretreatment of steel had influence on the bonding strength. The epoxy bonding ensured a reliable connection between the steel deck and the rigid pavement even with a poor pretreatment of the steel surface. Steel yielding occurred prior to the cohesive failure between the steel and the concrete. In addition, the bonding layer had a non-uniform shear stress distribution that the stress at the rib-to-deck joint was higher than other positions. The steel deck with adhesively bonded rigid pavement exhibited good ductility and high bearing capacity.