In-Plane Shear Strength Improvement of Hollow Concrete Masonry Panels Using a Fabric-Reinforced Cementitious Matrix

An overview of an experimental program investigating the effectiveness of fabric-reinforced cementitious matrix (FRCM) to limit the damage in shear critical unreinforced hollow concrete masonry assemblages is presented. The experimental program involved the mechanical testing of the constituent materials and the diagonal shear testing of 16 masonry panels constructed to replicate the masonry types prevalent in nonductile reinforced concrete frames with masonry infill buildings. The test variables investigated included the masonry type, the FRCM fabric material, and the number of FRCM layers. Three FRCM fabrics (basalt, glass, and carbon) and two masonry types (200 and 150 mm thick) were used. The FRCM strengthening changed the failure mode from brittle bed joint sliding to a more gradual distributed diagonal cracking and/or toe crushing, with a shear strength increase of 104-258% for 150-mm thick masonry panels and 69-156% for 200-mm thick masonry panels. A substantial increase in the ductility and energy dissipation capacity was also noted for the FRCM-strengthened masonry panels. The shear stress-strain behavior, deformation capacity, pseudoductility, energy dissipation, and stiffness characteristics were analyzed and discussed. The behavior of the FRCM-strengthened panels was predicted using analytical equations, and the predicted values were compared to the experimental results.