Experimental and numerical study on the shear behavior of stone masonry walls strengthened with GFRP reinforced mortar coating and steel-cord reinforced repointing

The research work herein presented is aimed at investigating the structural behavior of stone masonry walls reinforced through different strengthening techniques. In particular, the difference between them is given by (i) application on both faces of a mortar coating reinforced with a GFRP (Glass Fiber Reinforced Polymers) mesh; (ii) application of the GFRP jacketing on one side only and (iii) application of a hybrid technique, obtained by the combination of a GFRP jacketing, on one side, and a reinforced repointing with steel-strands, on the other. Shear-compression (SC) and diagonal compression (DC) experiments were carried out on full-scale masonry walls both reinforced (RM) and unreinforced (URM), as reference. The structural effectiveness of the various reinforcing techniques is highlighted. Further assessment of test predictions was then performed by means of well-calibrated finite-element (FE) numerical models able to properly take into account the effective contribution of each specimen component. Interesting correlations were generally found between test predictions and corresponding numerical models. The experiments, as shown, generally evidenced a good effectiveness of the strengthening techniques proposed, with particular concern to that with the reinforced coating on both sides, and highlighted also the importance of the transversal connectors to prevent in plane cracks in the masonry and the detachment of the reinforced coating.