Abstract

Reinforced masonry (RM) shear walls are the key structural elements widely used to resist lateral loads in masonry buildings due to their capability to provide lateral strength, stiffness, and energy dissipation. The flexural behaviour of RM shear walls is well defined and follows the simple flexural theory of reinforced concrete structures based on plane-section assumption. On the other hand, the shear behaviour of RM shear walls in the plastic hinge region is more complex due to the interaction between the nonlinear responses of their constituent materials, namely: concrete masonry blocks, mortar, grout, and steel reinforcement. The main objective of this thesis is to evaluate the inelastic behaviour of fully grouted RM shear walls that are dominated by shear failure. The research objective was achieved by conducting experimental, numerical, and analytical studies.
The experimental work involved assessing the response of nine full-scale fully grouted rectangular RM shear walls when subjected to in-plane axial compressive stress, cyclic lateral excitations, and top moment. The main variables considered were the level of axial compressive stress, shear span to depth ratio, horizontal reinforcement ratio, anchorage end detail, and the spacing of horizontal and vertical reinforcement. The effect of the studied parameters is analyzed and presented in detail according to force-based, displacement-based, and performance-based seismic design considerations. Moreover, nonlinear finite element models were developed to simulate the behaviour of RM shear walls subjected to cyclic loading, and validated using results from the nine RM tested walls. Good agreements with the experimental load-displacement hysteretic loops were achieved in all models. In addition, a parametric study was performed to consider more variations in some of the parameters examined in the experimental work, which arrived at similar conclusions of the tested walls.
Using the results of the tested RM shear walls together with the parametric study, an equation for predicting the in-plane shear strength, Vn, of RM shear walls was proposed and verified with results of 64 RM wall tests from five sources in the literature. Statistical analysis was performed to evaluate the accuracy of the proposed equation against ten widely-used equations, including the design equations given in the Canadian Standards Association CSA S304-2014, the US Masonry Standards Joint Committee MSJC-2013, and the Standards Association of New Zealand NZS 4230:2004. The analysis shows that the proposed equation provides a sufficiently conservative and more accurate prediction for Vn than any of the other evaluated equations.