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 of flanges. 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-to-length 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.