新型装配式混凝土框架连接节点抗震性能试验

Experimental on seismic behavior of new fabricated concrete frame joints

为推广装配式混凝土框架结构的应用,提出3种不同的新型装配式钢筋混凝土框架中节点连接形式,进行低周往复荷载试验。对比各试件的破坏形态、滞回性能、刚度退化、累积耗能和节点剪切变形等抗震指标。研究结果表明:采用方钢管连接的装配式混凝土节点呈现梁端弯曲破坏,采用工字钢连接或对拉螺栓连接的节点呈现节点核心区剪切破坏。采用方钢管的连接形式既能改善节点核心区的破坏形态,又能提高其承载能力、变形能力、耗能能力和梁端转动能力,同时显著改善节点的滞回特性,减小核心区的剪切变形。在弹塑性和塑性变形阶段,采用方钢管连接形式的装配式混凝土节点的抗震性能优于工字钢连接和对拉螺栓连接的节点。此外,采用工字钢连接形式比对拉螺栓连接形式的节点具有更高的承载能力、耗能能力和较小的核心区剪切变形。

In order to promote the application of the prefabricated concrete frame structure, three new assembled reinforced concrete frame jointswith different connection forms was tested under the low-cycle reverse loading. The seismic indicators such as failure mode, hysteresis behavior, stiffness degradation, accumulated energy dissipationand shear deformation of each specimen were compared. The results show that the fabricated concrete joints connected by square steel tube has exhibited bending failure at the beam end and the joints was connected by the H-steel or bolts have exhibited shear failure in the joint core zone. The connection form of the square steel tube cannot only improve the damage mode of the joint region, but also enhance its bearing capacity, deformation capacity, energy dissipation capacity, and beam rotation capacity,and also significantly improve the hysteretic performance, decrease the shear deformation. In the elastoplastic and plastic deformation stages, the seismic behavior of the fabricated concrete joint with square steel tube is superior to the joints with the H-steel or boltsconnectors. Moreover, the joint with the H-steelconnector has higher bearing capacity, larger energy dissipation and smaller shear deformation than that of with bolts connector.