Experimental study on seismic behavior of SCRC column base joints with replaceable dampers

Abstract

Self-centering reinforced concrete (SCRC) column base joints can effectively reduce residual drift under horizontal seismic action as unbonded post-tensioning strands provide self-centering capacity. The connection also utilizes a steel tube collar, and a new type of replaceable damper to dissipate seismic energy. Six specimens of SCRC column base joints were designed, constructed and subjected to cyclic horizontal loading in conjunction with axial compression. The experiments investigated the mechanical behavior, hysteretic curve, energy dissipation capability, self-centering capacity, and replaceability of the SCRC column base joints. The experimental results showed that the SCRC column base joint performed satisfactorily in moment capacity, residual drift, and energy dissipation. The behavior of specimens with replaced dampers was almost the same as their behavior with the original dampers, indicating the efficacy of replacement. Moreover, the steel tube protected the concrete at the column base from local compression failure.