Experimental study on seismic behavior of prefabricated RC frame joints with T-shaped columns

Abstract

A novel type of prefabricated frame joint with T-shaped column has been proposed for highly seismic regions in this study. Based on cyclic loading test, the seismic behaviors of four prefabricated and cast-in-situ joints were investigated in terms of failure modes, strength, ductility, stiffness degradation, hysteretic curve and energy dissipation. Compared with the cast-in-situ counterparts, the proposed prefabricated joints exhibited similar failure mode, satisfactory strength, comparable stiffness and greater ductility. The positive bearing capacities of the prefabricated joints were slightly lower than that of the cast-in-situ joints, while the negative bearing capacity of the prefabricated joint was 73%–90% of the cast-in-situ counterpart. For the interior joints, the hysteretic curves were relatively symmetric and the energy dissipation of the proposed prefabricated joint was rather close to the cast-in-situ counterpart. The influences of various factors, including joint type, reinforcement splice, superimposed slab and loading direction, are discussed. A simplified theoretical model was proposed to predict the bearing capacities of the joints. The research will provide suggestions for prefabricated joint design and promote the development of prefabricated concrete frame structure.