Numerical simulation and theoretical analysis on RECC ring beam joints for RECC-encased CFST composite columns

Abstract

The failure mechanisms of reinforced engineered cementitious composite (RECC) ring beam joints were numerically analysed using finite element (FE) software of ATENA. The failure mode, load-carrying capacity, ductility, and distribution of the strain in the steel reinforcement were comprehensively investigated. The simulation results showed that the RECC ring beam significantly contributed to the mechanical property of the joint. Part of the circumferential reinforcement in the ring beam contributed to the shear strength and improved the strength of the core ECC by the restraint effect. A total of 46 specimens were subsequently investigated to examine the influences of the circumferential reinforcement ratio, stirrup ratio, axial compressive ratio, tensile properties and compressive strength of ECC on the seismic behaviour of RECC ring beam joints. Finally, a simplified softened strut-and-tie model was proposed to predict the shear-carrying capacity of the RECC ring beam joint.