Shear performance of brick masonry walls reinforced with twisted steel bars

The present paper presents a study on the in-plane shear performance of solid clay brick masonry walls reinforced with near-surface mounted twisted steel bars. Masonry assemblages were fabricated representing those used in masonry-concrete buildings such as those found in Lisbon, built during the decades of 1930-1950. Solid clay bricks laid in Flemish bond using cement-lime blended mortar were used in the construction of fifteen wallette specimens. Three reinforcement layouts were applied on both faces of the wallettes, namely: grid (vertical + horizontal bars), vertical-only, and horizontal-only. Three unreinforced and nine reinforced specimens were subjected to diagonal compression tests. Three other unreinforced specimens were subjected to axial compression tests. The effectiveness of the proposed strengthening solution was discussed. The findings indicate that the proposed strengthening solution substantially increased the shear strength and greatly improved the ductility of the masonry wallette assemblages, pointing to its interest in practice. Although the number of tests performed is significant (considering its complexity), it should be noted that the representativeness of the results could be improved by performing more tests. The incorporation of results from other studies (in progress within the RESIST2020 research project), namely, regarding the walls out-of-plane behavior, will allow for a more complete characterization of the benefits of the reinforcement solution.