Partially grouted masonry walls with different horizontal reinforcement types: North American-compliant experimental performance for low seismic risk areas

The type of horizontal reinforcement can play a major role in the shear response of partially grouted (PG) masonry walls, particularly in the damage pattern and the post-peak behavior. Bond beam reinforcement and bed joint reinforcement are the two reinforcement types most commonly used in practice; however, there is a lack of comparative studies between these two reinforcement strategies. To advance knowledge on this matter, this paper presents the results of an experimental study made up of 4 full-scale walls tested under cyclic lateral loading. Two height-to-length aspect ratios (H/L = 1.0, 1.86) and two reinforcement types per aspect ratio were considered. These walls were designed to reflect practical details and construction practices for PG walls in low seismic hazard areas. Lateral load tests showed that the peak strength of walls with similar aspect ratios had no significant difference regardless of the reinforcement type used. Bed-joint reinforcement proved to be a vital option as a shear reinforcement for controlling the crack width. The preliminary assessment of in-plane strength prediction equations for PG walls revealed that the general flexural analysis method provides a satisfactory estimation of flexural strength. In contrast, code-based equations had a highly conservative prediction of shear strength when imposing the upper limit. In addition, the Canadian Standards Association (CSA) and The Masonry Society (TMS) equations used to predict the in-plane shear strength had a noticeable discrepancy in the contribution of the equation's parameters, particularly in the axial stress, horizontal reinforcement, and the upper limit, which highlighted the need to revise and reconsider the contribution of each design parameter used by these expressions. •Quasi-static tests of four PG-RM walls are reported.•Different horizontal reinforcement schemes are assessed.•The performance of tested walls is analyzed concerning energy dissipation, displacement ductility and ductility reduction factors.