Shear Strength of Coupled Autoclaved Aerated Concrete Confined Masonry Walls

Abstract

The in-plane shear behavior of autoclaved aerated concrete (AAC) confined masonry walls has been studied considering only cantilever walls. In coupled walls, there are changes in the bending moments and axial forces of individual confined walls because of the presence of coupling beams. Those changes have not been considered in current shear design recommendations for AAC confined walls. The objective of this work was to study the shear behavior of coupled AAC walls. A total of four reduced-scale walls were tested under in-plane reverse cyclic lateral loads. In this study, 1- and 2-story-high coupled walls were considered. Coupled walls consisted of individual AAC confined walls and reinforced concrete coupling beams. Two aspect ratios were considered for the individual AAC confined walls. It was observed that the cracking pattern of the 1- and 2-story coupled walls was similar, respectively. The shear strength of individual AAC confined walls increased as the aspect ratio decreased, the shear span over the wall length ratio decreased, or the axial compressive force increased. Similarly, the shear strength and stiffness of coupled walls increased as the aspect ratio of individual AAC confined walls decreased and the shear span over the wall length ratio decreased. On the contrary, the drift ratio of coupled walls increased as the aspect ratio of individual confined walls increased and the shear span over the wall length ratio increased. A design shear strength equation was proposed for AAC confined walls. This equation is a function of the shear span over the wall length ratio. The proposed equation predicted well the experimental shear strength and can be used for cantilever and coupled AAC confined walls.