Experimental study on seismic behaviors of prefabricated embedded concrete-filled steel tube special-shaped column exterior frame

Abstract

The new type of prefabricated embedded concrete-filled steel tube (CFST) special-shaped column structure delivers green and environmentally-friendly strengths and high space. In this study, a full-scale frame test piece with one frame façade, two stories and two spans are designed and fabricated for purposes of exploring the seismic performance and node connection safety of filled built-in steel tube concrete-filled special-shaped column, and low cyclic load testing is implemented. The bearing characteristics, deformation capacity, energy-dissipating capacity, ductility and stiffness degradation of the test piece are analyzed. The results showed that the failure mechanism is typical beam hinge mechanism. The fabricated beam-column and column-column connection nodes in this paper are safe and reliable. The hysteretic curve of fabricated embedded CFST special-shaped column is full, the ductility and energy dissipation capacity of fabricated embedded CFST special-shaped column are better than such indexes of ordinary reinforced concrete special-shaped column. The inter-story displacement angle is 1/32 when the test piece is damaged, being significantly higher than the limit value of elastic-plastic inter-story displacement angle of 1/50 under strong earthquake. The precast embedded steel-reinforced concrete special-shaped column structure is only required to be connected with steel ribs to significantly improve the construction speed and quality, delivering great economy.