Effect of Mortar Type on the Seismic Response of Partially Grouted Reinforced Masonry Shear Walls

Since the establishment of ASTM standard C91, masonry cement mortars have become widely used for masonry construction in low to moderate seismic regions. However, the Masonry Standards Joint Committee Code prohibits the use of masonry cement mortars in lateral force resisting systems for structures that fall into Seismic Design Categories D, E, and F. The general objective of this study is to examine the appropriateness of this restriction in light of past research and, if necessary, propose additional research required to fill any existing knowledge gap. Since information about the specific impact of the physical and mechanical properties of masonry cement mortars on the seismic response of masonry shear walls is limited, this paper primarily focuses on research that has identified the influence of mortar on the behaviour of masonry assemblages. In particular, this paper summarizes the available literature on in-plane pier response as well as the response of masonry assemblages under axial compression, flexural tension, bed joint shear and diagonal tension. The primary gap identified through this literature review was the lack of experimental research that addressed the response of reinforced masonry shear walls constructed with masonry cement mortar. To establish a comprehensive and efficient research program to fill this gap, the available literature related to the behaviour of partially grouted reinforced masonry shear walls was also reviewed and key factors that influence response were established. The paper concludes by summarizing the primary findings of past research and briefly outlining the proposed experimental program.