Flexural and shear strengthening of un-reinforced masonry with FRP bars

Un-reinforced masonry (URM) walls are one of the oldest and most widely used types of construction in the world but they are prone to failure when subjected to overstresses caused by out-of-plane and in-plane loads. The successful use of near surface mounted (NSM) fiber-reinforced polymer (FRP) bars for strengthening of concrete members has been extended, in this experimental program, to URM walls: circular and rectangular FRP bars have been embedded in grooves of different sizes using of two pastes: a latex modified cementitious paste and an epoxy-based paste. The results, in terms of flexural strengthening and shear strengthening, are presented and discussed in this paper. They show the potential of this technique for retrofitting masonry structures: the installation time is minimal, the appearance is preserved, the capacity marked increased and the behavior at failure more ductile.