Seismic behaviour of precast SRC beam-CFST column joints with cantilever beam splicing

Abstract

The resistance advantages of well-known high-performance components in assembly structures, such as steel reinforced concrete (SRC) beams and concrete-filled steel tube (CFST) columns, are still plagued by the connections between them, and there are a paucity of studies on the behaviour of precast joints employing such members. To fill the knowledge gap in this area, this paper reported quasi-static tests of four half-scale precast beam-column joints, each with a steel reinforced concrete (SRC) beam and concrete-filled steel tube (CFST) column. Based on the cantilever beam connector with better constructability and serviceability, the splicing position and splicing method were selected as the variables to evaluate the seismic performance of four precast joints and to reveal the feasibility of using these assembly details. The test results showed that the four joints experienced bending failures at the beam end, along with extremely plump shape of hysteresis curve. Owing to the fact that the more distant splicing position lifted the deformation restriction on the concrete at the beam end, the nonlinear deformation capacities of the distal splicing joints is better than the proximal splicing ones, by at least 14%. Except for the proximal splicing joint, the other joints had more stable carrying capacities and at least 22% lighter stiffness degradation than the referenced monolithic joint. Considering the initial stiffness values, the four joints in this study were classified as semi-rigid joints as recommended by ENV 1993-1-8. The results obtained from this study can provide a reference for the application of assembly technology to frame joints with composite members.