Experimental seismic study of precast hybrid SFC/RC beam-column connections with different connection details

摘要

A new type of precast hybrid steel fiber concrete (SFC)/reinforced concrete (RC) beam-column connection with different connection details was developed for precast concrete frames. In this study, seven concrete beam-column connections, six precast specimens, and one monolithic joint were subjected to a constant axial load and a reversed cyclic loading. The main test variables were the end-plate connection forms and SFC usage in the core region and the connection section. The construction process of the proposed hybrid connections was convenient and fast. The load-displacement hysteresis curves and failure modes of the precast connections were obtained, and the seismic behaviors in terms of connection stiffness, strength, energy dissipation, and shear deformation in the joint core were evaluated. The results revealed that the proposed precast concrete connections had higher strength, slower stiffness degradation, and greater energy dissipation capacity, thereby illustrating that the specimens had a satisfactory ability to resist seismic loads. The shear deformation of the proposed joints was reduced because of the tensile deformability of the SFC and the yielding steel connectors, while the shear strength was considerably enhanced. The cracking pattern in the core region of the hybrid connections with the SFC was well controlled. The integrity of the connection section was maintained. Furthermore, the SFC and steel-plate connectors were vital to the performance of the system.