Seismic performance and force transfer of wide beam–column joints in concrete buildings

Various experimental investigations have been conducted on wide beam–column connections in reinforced concrete buildings in the past decade. However, the cyclic behaviour and failure modes of such connections under seismic loading are not clearly understood due to the complexity of force-transfer mechanisms in joint cores. In this paper, an investigation is conducted on the cyclic behaviour and force-transfer mechanisms of reinforced concrete exterior wide beam–column joints using computational simulation. Exterior wide beam specimens with different beam widths and reinforcement details are simulated under reversed cyclic loading using well-calibrated finite-element models with appropriate material constitutive laws and boundary conditions. It is shown that wide beam–column joints have good post-peak behaviour compared with conventional beam–column joints, which show severe pinching behaviour and low inherent ductility, although having higher strength and stiffness. Two load-transfer paths in wide beam–column connections have been identified, which are characterised by two struts with different inclined angles in the connecting wide beams and transverse beams. On the basis of research findings, reinforcement details and width limitation of wide beams are addressed in connection with the design of exterior wide beam–column connections.