Influence of masonry texture on the shear strength of FRCM reinforced panels

One of the innovative retrofitting systems for the improvement of the shear behavior of masonry elements is the use of Fiber Reinforced Cementitious Matrix (FRCM). Indeed, their application on masonry panels can determine a less brittle shear failure with respect to unreinforced panels and an increase in the load bearing capacity. The masonry typologies on which this strengthening technique can be applied are extremely variable, depending on the nature of the components, the characteristics of the mortar, the masonry texture and the transversal connection between the wall wythes. The goal of this work, part of an extended experimental campaign, was to analyze the effectiveness of the same strengthening system applied on two different masonry typologies. Therefore, diagonal compression tests were performed on four masonry samples realized using clay bricks and hydraulic lime-based mortar. In particular, the brick masonry panels were characterized by two different textures: Flemish bond and header bond. The tests were executed according to ASTM E519 under displacement control in order to capture the post-peak behavior. Benefits observed in the capacity, shear stiffness and ductility of the samples were analyzed, with reference to the differences between construction typologies. Finally, the results were compared with the theoretical ones computed using the formulations proposed in the Italian Guidelines CNR DT 200.