Cyclic Loading Test on Beam-to-Column Connections Connecting SRRAC Beams to RACFST Columns

This paper presents an experimental study conducted on the seismic behavior of beam-to-column connections based on the components of steel reinforced recycled aggregate concrete beams and recycled aggregate concrete-filled steel tube columns. The main test parameter of the specimens is the replacement ratio of recycled aggregate. The experiment process and failure modes of all specimens were investigated in detail. Several parameters such as hysteretic behavior, bearing capacity, strength and stiffness degradation, ductility coefficients, and energy dissipation were also analyzed. The test results showed that slipping appeared between the steel tube and beam concrete (sandwiched between the circumferential stiffening plates) while the specimen yielded. The shapes of the moment versus rotation hysteresis curve at the end of the beam were plump, which runs through a linear, reverse “S”-shaped and spindle-shaped deformation stages. Analysis of the seismic evaluation index showed that the replacement ratio of the recycled aggregate had no significant effect on the seismic performance. Moreover, a simulation study was also carried out using FEM, and the results showed good agreement with the skeleton curves obtained from the test. Finally, a simplified calculation model was established and the bearing capacity calculation equation of connections was proposed. Compared with the test results, the calculation equation can satisfy engineering application requirements. The results presented in this paper can be used as reference for engineering practice.