聚丙烯纤维增强混凝土干接缝的抗剪性能

Shear strength of polypropylene fiber reinforced concrete dry joints

为了研究聚丙烯纤维对预制节段混凝土桥梁干接缝剪切性能的影响,本试验以接缝类型、键齿数量、混凝土类型、聚丙烯纤维掺量和水平正应力大小为试验参数,对C40普通混凝土和C40聚丙烯纤维增强混凝土试件进行抗剪性能的试验研究。记录了试件开裂载荷、极限载荷和残余载荷,同时也研究了试件开裂破坏模式和规范化剪应力-竖直位移曲线的关系。试验结果表明:聚丙烯纤维有利于提高干接缝试件的开裂荷载、极限荷载以及有利于试件的塑性变形;聚丙烯纤维对阻止干接缝试件开裂能起到一定的作用,但是聚丙烯纤维不同掺量的影响规律不明显。

In order to research the effect of polypropylene fibers on shear strength of dry joints in precast concrete segmental bridges, experiments were conducted to investigate the shear behavior of C40 regular concrete and C40 polypropylene fiber reinforced concrete. The main parameters for tests were joint types, key numbers, concrete types, amount of polypropylene fibers, and horizontal confining stress levels. The cracking loads, ultimate loads, and residual loads were recorded. The cracking pattern, failure mode and normalized shear stress-vertical slip curve relationship were investigated. It can be concluded that the utilization of polypropylene fibers can improve cracking loads, ultimate loads and the deformation capacity of dry joints specimens. The polypropylene fibers can prevent cracking, but the effect of different amount of polypropylene fibers on the shear behavior is not obvious.