新型箍筋装配式混凝土梁柱节点抗震性能研究

Research on Seismic Performance of Prefabricated Concrete Beam-to-Column Joints with New Stirrups

针对一笔箍筋和多螺旋箍筋(简称“新型箍筋”)优异的约束效果,提出新型箍筋增强装配式混凝土梁柱节点。按照节点强弱、类型和施工方法以及箍筋形式的不同,共设计6个足尺混凝土梁柱节点试件。依据低周往复荷载试验结果,对节点的破坏形态、滞回曲线、骨架曲线、延性、耗能能力、强度退化、刚度退化和节点转角进行讨论。结果表明:强节点试件发生梁端弯曲破坏,弱节点组试件发生节点剪切破坏;新型箍筋装配式梁柱节点滞回曲线饱满,其抗震性能指标均和现浇节点相差不大;新型箍筋装配式节点转角变形大于现浇节点。此外,GB 50010—2010《混凝土结构设计规范》能适用于新型箍筋装配式梁柱节点的设计,并且具备一定的安全储备。

Since the one-time forming stirrups and multi-spiral stirrups(refers to as "new stirrups") have an excellent confined effect, a prefabricated concrete beam-column joints with new stirrups was proposed. Based on the difference of joint strength, joint types, construction methods and stirrup types, six full-scale concrete beam-column joint specimens were designed. According to the quasi-static load tests, the failure modes, hysteresis curves, skeleton curves, ductility, energy dissipation capacity, strength degradation, stiffness degradation, and joint rotation were discussed. It was found that: strong joint specimens collapsed by the bending failure of beam ends, and weak joint specimens failed by the shear failure of joint zones;the prefabricated concrete beam-column joints with new stirrups had plump hysteresis curves, and their seismic performance indexes were similar to that of the cast-in-place joints;the joint rotation of the prefabricated concrete beam-column joints with new stirrups was larger than that of the cast-in-place joints. In addition, the Code of Concrete Structures Design(GB 50010—2010) can be used to design the prefabricated concrete beam-column joints with new stirrups, accompanied with a certain degree of safety reserve.