Cyclic Shear Behavior of High-Strength Concrete Structural Walls

High-strength concrete (HSC) walls having compressive strength of approximately 100 MPa (14,500 psi) were tested under cyclic lateral loading to investigate their shear behavior. The parameters included were height-to-length ratio of the walls, vertical and horizontal web reinforcement ratios, and the effects of boundary elements in the form offlanges. The experimental results show that shorter walls exhibit greater shear strength than taller walls. Both vertical and horizontal web reinforcements contribute significantly to increasing the shear strength of the walls, with the horizontal web reinforcement being more effective for walls having height-tolength ratio from 1.0 to 2.0. With increase in height-to-length ratio of walls, the concrete contribution to the shear strength decreases while the web reinforcement contribution increases. The presence of flanges also significantly increases the shear strength of HSC walls. Experimental wall shear strengths from this study as well as from literature were compared with predictions from the ACI Code and Eurocode provisions. It can be seen that both ACI and Eurocode do not give consistent safety factors. The ACI method can be unsafe for low-strength concrete walls, while the Eurocode is overly conservative in almost all cases.