C.L. TALLON(1), D.I. MCLEAN(1), D.G. POLLOCK(1) and T.C. YOUNG(2)(1) Washington State University (2)Northwest Concrete Masonry Association

Past research has shown that the flexural performance and ductility of reinforced masonry shear walls loaded in-plane are affected by several interacting factors, including axial load, aspect ratio, material strengths, and the amount of flexural reinforcement. To better understand the effects of these parameters, moment-curvature analyses were performed on masonry shear walls with varying flexural reinforcement ratios, axial loads and material properties. Curvature capacities obtained from the analyses were compared to curvature demand based on the International Building Code drift limits. Questions have arisen on the basis of the code provisions limiting the flexural reinforcement for masonry shear walls, especially for low aspect ratios since behavioural modes other than flexure will dominate the response. The moment-curvature analyses predict curvature capacities significantly greater than those the code currently considers. Consequently, the code flexural reinforcement limits are overly conservative for shear walls with an aspect ratio greater than 2.5.