Influence of Type of Steel Reinforcement on Seismic Behaviour of Flanged and Rectangular RC Structural Walls

Dual structural systems (moment resisting frame with RC structural walls) are common in mid and high-rise buildings due to their better performances in past earthquakes. The seismic behaviour of RC structural walls (commonly known as shear walls) having rectangular cross-sectional shapes has been studied extensively in past decades but the study on the behaviour of flanged RC walls is relatively limited. In this study, the seismic behaviour of flanged (T-shaped) RC walls and rectangular RC walls with different grades of reinforcement have been compared using nonlinear finite element analysis. The numerical simulations have been carried out using the software ABAQUS. The Concrete Damage Plasticity (CDP) model is employed as the constitutive model in the case of concrete. In the case of steel reinforcement bars, the experimental stress–strain curves of two types of rebar having theoretical yield values of 600 MPa (ductile) and 500 MPa (non-ductile) are used instead of any prescribed idealised model. It is observed that the yield drift for the RC wall built with high-strength (fy = 600 MPa) ductile reinforcement is significantly higher as compared to the wall with normal-strength (fy = 500 MPa) reinforcement. On the other hand, it is found that the influence of the different types of reinforcement on the ultimate drift of the RC wall depends on the nature of the corresponding failure mode.