Mahmoud Zaki Abdelrahman, Belal AbdelRahman, and Khaled Galal
i Ph.D. Student, Concordia University, Montreal, Quebec, Canada, mahmoud.abdelrahman@mail.concordia.ca
ii Postdoctoral Fellow, Concordia University, Montreal, Quebec, Canada, belal.abdelrahman@concordia.ca
iii Professor, Concordia University, Montreal, Quebec, Canada, khaled.galal@concordia.ca
ABSTRACT
In-plane shear strength is one of the key parameters in the design of concrete masonry shear walls. According to the North American masonry standards (i.e. CSA S304-14 and TMS 402/602-22), the shear forces are primarily resisted by masonry and horizontal shear reinforcement, whereas the New Zealand standards (NZS 4230) consider the contribution of vertical reinforcement in the calculation of shear strength. This study experimentally investigates the in-plane shear (diagonal tensile) strength of full-scale masonry assemblages (i.e., wallets). Nine full-scale wallets with dimensions of 1.2 ×1.2 m in accordance with ASTM E519 were constructed to yield three groups of specimens, namely, fully grouted wallets with a reinforcement ratio of 0.42%, partially grouted wallets with a reinforcement ratio of 0.17%, and ungrouted wallets. The results showed that the vertical reinforcement reached its yield capacity, significantly contributing to the shear strength of the tested wallets. Using these results, along with data from 44 previously studied masonry walls with different vertical and horizontal reinforcement ratios, the shear strength expressions proposed by the North American and New Zealand masonry standards were evaluated. The results demonstrated that CSA S304-24 produced the most conservative predictions compared to other standards, while NZS 4230 had the closest shear strength values to those observed by the experimental data. This can be attributed to the contribution of vertical reinforcement in resisting the shear stress in the NZS 4230. An adjustment to the shear strength equation of CSA S304-14 is proposed to incorporate vertical reinforcement, which has resulted in more precise and reliable predictions of masonry shear strength.
KEYWORDS: Vertical reinforcement, Shear strength, Concrete masonry walls, Diagonal tension, Horizontal reinforcement.
036-Abdelrahman.pdf
