Unreinforced masonry (URM) walls often exhibit poor seismic performance, particularly when openings interrupt the load path and create stress concentrations that significantly reduce in-plane shear capacity. This study investigates welded steel mesh (WSM) as a practical and economical strengthening solution for URM walls with openings. Eleven masonry panels—including solid walls and walls with central openings—were tested under diagonal compression (ASTM E519), examining various WSM configurations such as orthogonal, diagonal, partial, and full layouts. The strengthened walls showed marked improvements in ultimate load, stiffness, and energy absorption, with the full diagonal mesh providing the highest enhancement. Although openings reduced shear capacity by 49%, WSM reinforcement helped redistribute stresses and delay crack initiation. A validated finite element model supported a parametric study, which identified an optimal WSM ratio of 0.08% and showed that large openings significantly reduce strength. The results confirm WSM as an effective retrofit for improving URM seismic performance.
Ghalla et al. (Tue,) studied this question.