Three-dimensional cyclic performance on new ring-beam connection between concrete-filled tubular column and reinforced-concrete beams

This paper introduces a new type of connection between concrete-filled steel tubular (CFST) column and reinforced concrete (RC) beam through a transitional RC ring beam encircling the CFST column. Four scaled specimens, representing an interiorcolumn joint, were tested under bi-directional cyclic loads to examine the seismic performance and the influence of the reinforcement on the joint. Load-deformation response, failure mode, strain distribution, and energy dissipative performance were presented. Test results indicated ductile performance and the multi-directional nature of the force system in the ring beam. Finite element models were also calibrated against test results and results from parametric analysis confirmed the effect of tube diameter and longitudinal reinforcement in the ring beam on the structural performance.