Experimental Testing of Partially Grouted Masonry Shear Walls with Different Horizontal Reinforcement Types

Partially grouted (PG) masonry shear walls are widely used as lateral force-resisting systems in North America due to their economic value and practicality. Unlike fully grouted (FG) shear walls, only cells containing reinforcing steel are grouted in PG walls leaving the remaining cells hollow. With the wall assemblage consisting of materials such as masonry block, mortar, grout, and reinforcing steel, the overall behaviour is complex. To understand better the in-plane response of PG walls, experimental testing has been used as a viable tool. However, few experimental studies have been carried out to investigate PG walls compared with FG walls. Moreover, if available, some studies lacked full-scale test specimen size, compliance to the actual masonry construction, and well-documented reports. As a result, North American code equations have been obtained based on FG walls data leading to uneconomical designs while being unconservative in some cases. This paper describes the preliminary experimental results of four full-scale partially grouted masonry shear walls. These walls were designed and built to reflect the conventional construction practice, including wall geometry, reinforcement distribution, boundary conditions, and loading scenario. All the walls were subjected to constant vertical load, and reverse in-plane lateral cyclic load incrementally increased. The variable design parameters investigated in this study were: aspect ratio and horizontal reinforcement type (bond beams or bed-Joint reinforcement). These walls’ response was evaluated in terms of damage progression, in-plane hysteresis curves of lateral load against drift ratio, and energy dissipation. The experimental results revealed that lateral load capacity attained by walls with similar aspect ratios had no significant difference regardless of the reinforcement type. On the other hand, the aspect ratio had a significant effect. Moreover, the effect of bed-joint reinforcement was more visible in controlling the damage progression by distributing new cracks throughout the wall panel instead of widening the existing cracks.