Shear Strength of Normal to High Strength Concrete Walls

This paper presents an analytical study on the behavior of normal to high strength concrete walls. Experimental
data of concrete walls were collected from available literatures and several building code provisions were evaluated by
comparing nominal wall strengths calculated using code formulas with experimental wall strengths. Moreover, behavior of
concrete walls as influenced by various parameters was investigated by plotting the normalized experimental wall strengths
and average shear stresses against shear span ratio, axial load ratio, web reinforcement ratio, and concrete strength. The
analysis results show that most code formulas underestimate wall shear strengths. It is shown that longitudinal web
reinforcement also has contribution to the shear strength of concrete walls even though it is not accounted in code formulas.
Furthermore, the accuracy of code formulas is also affected by variation in concrete strength. For example, the ACI code
considerably underestimates the shear strength of high strength concrete walls due to its limitation on maximum wall shear
stress which is quite conservative for high strength concrete walls. Thus, a modification of ACI code formula is proposed to
enhance its accuracy. The results show that the modified formula yields better predictions of both normal and high strength
concrete wall shear strengths.