Experimental study on seismic behavior of the self-centering RCS joint with replaceable buckling restrained dampers

Abstract

Reinforced concrete column and steel beam (RCS) joints are typically designed to ensure that plastic hinges develop at the end of the steel beams. The seismic energy is dissipated through the inelastic deformations of the steel beam. This design will result in difficult-to-repair damage and residual drifts. In this paper, a self-centering RCS joint with replaceable buckling restrained dampers and unbonded post-tensioning strands is proposed which can significantly eliminate residual drift under a strong earthquake. It dissipates seismic energy through replaceable buckling restrained dampers. It is easy to replace damaged dampers to ensure quick restoration of the capacity of the joint. Nine self-centering RCS joints were designed, constructed, and tested under cyclic loading. The experiments investigated the mechanical behavior, hysteretic curve, energy dissipation capability, self-centering capability, and replaceability of the self-centering RCS joints. The experimental results showed that the proposed joint experienced minimal residual drift and performed satisfactorily at the moment carrying capacity and energy dissipating capacity. Additionally, the specimens performed almost identically after the damaged dampers were replaced; thus, the effectiveness of damper replacement was verified.