Assessment of curved FRP-reinforced masonry prisms: Experiments and modeling

During the past decade, several approaches have been proposed to investigate the response of masonry structures strengthened by externally bonded Fiber Reinforced Polymer (FRP) reinforcements. Nowadays, regardless of the great efforts made, scarce information are available on the delamination behavior of reinforced curved substrates. An experimental and numerical study is presented herein, focusing on curved masonry prisms strengthened with a glass FRP strip. Both convex and concave configurations with a diverse curvature are considered for the specimens, constituted by four Portuguese bricks bonded by three joints of conventional mortar. The novel experimental data are interpreted in the light of fully three-dimensional finite element simulations. Under the simplifying assumption of perfect adhesion, such advanced model allows to reconstruct local processes inside the masonry prisms, such as the bulk damage distribution and the tractions over the interface, correlating them to the macroscopic response in terms of overall reaction force versus tangential slip. The effects of the geometrical curvature on the delamination response of the masonry prisms are critically and comparatively assessed by means of “step-by-step” numerical predictions together with a “direct” lower bound limit analysis approach. This topic is of paramount importance for structural engineering when dealing with masonry arches and double curvature structural elements.