In-Plane Seismic Performance of Fully Grouted Reinforced Masonry Shear Walls

Reinforced masonry (RM) shear walls are key structural elements widely used to resist lateral loads in masonry buildings due to their capability to provide lateral strength, stiffness, and energy dissipation. This paper investigates the in-plane seismic performance of fully grouted RM shear walls dominated by shear failure. The experimental work involved assessing the response of five single-story RM shear walls when subjected to in-plane axial compressive stress, cyclic lateral excitations, and top moment. The studied parameters were the horizontal reinforcement ratio, level of axial compressive stress, and shear span to depth ratio. Most of the current provisions in masonry design codes for nominal in-plane shear strength, $V_n$, for RM shear walls consider a percentage of the yield capacity for the shear resistance provided by the horizontal reinforcement, $V_s$. Moreover, they limit the effect of the shear span to depth ratio, $M/V{d}_v$, to an upper value of 1.0. The test results concluded that the horizontal reinforcement could contribute 100% of its yield capacity toward $V_n$. In addition, increasing $M/V{d}_v$ from 1.25 to 1.875 resulted in a significant reduction in the shear strength by 25%, which means that limiting the effect of $M/V{d}_v$ to an upper value of 1.0 is overestimating $V_n$ of RM shear walls at high values of $M/V{d}_v$. However, this reduction is accompanied by higher displacement ductility. On the other hand, increasing the axial compressive stress resulted in a higher $V_n$ with more brittle failure.