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To improve the bearing capacity and optimize the allocation of ring beam connection, a new type of steel reinforced engineered cementitious composite (ECC) ring beam connection linking the reinforced concrete (RC) beam and the concrete‐filled steel tube (CFST) column was presented. The superior tensile property of ECC can significantly solve the cracking problem that weakens the bearing capacity of the ring beam. In this paper, the failure mechanisms, contact press analysis and strain distribution of steel reinforcement for reinforced engineered cementitious composite (RECC) ring beam joints were analyzed by finite element analysis. Moreover, based on the ultimate equilibrium method, a comprehensive study was conducted on the stress transfer mechanism for the RECC ring beam joint. The bearing capacity model and simplified computational method for the beam‐to‐CFST column with RECC ring beam were proposed. Finally, the calculation method was demonstrated with experimental results. Comparison results showed good agreement, proving that the proposed bearing capacity calculation model had reliability and theoretical significance. [ABSTRACT FROM AUTHOR]

This paper investigates the axial compressive behavior of a through-beam connection between concrete-filled steel tubular (CFST) columns and reinforced concrete (RC) beams. In this connection system, the steel tube is completely curtailed at the corresponding beam location, with the longitudinal steel reinforcing bars for the beam remaining continuous through the connection region. A strengthening ring beam is used to enlarge the connection zone in order to compensate for the possible decrease of the axial load-carrying capacity as a result of the discontinuity of the steel tube that encases the column. Two series of axial compressive tests on 32 beam-column specimens are reported. The first series of tests, including 5 full-scale connection specimens with CFST columns, show that with proper design, the axial loadcarrying capacity of the connection can be higher than that of the CFST column. The feasibility of this type of connection is verified. The second series of tests, including 27 specimens with only the connection zone, evaluate the ultimate strength of the connection. It is shown that the height and the area ratio of the reinforcement in the ring beam have significant influence on the axial load-carrying capacity of the connection zone. Taking into consideration the confinement produced by multiple layers of ring bars and the effect of local compression, a formula for predicting the ultimate axial compressive strength of this connection is proposed. The accuracy of the proposed formula is validated through comparisons of the theoretical and experimental results. [ABSTRACT FROM AUTHOR]

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 interior-column 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. [ABSTRACT FROM AUTHOR]