Shear response of brick masonry small assemblages strengthened with bonded FRP laminates for in-plane reinforcement

Modern composite materials are receiving increasing attention as reinforcing solutions applicable to the repair and strengthening of concrete and masonry structures. Aiming towards a better characterization of the possibilities offered by these materials, the research work reported here investigates the shear response of small masonry assemblages strengthened externally with sheets made of glass and aramid fiber reinforced polymer laminates. An alternative strengthening approach provided by microlaminated wood is also investigated.The assemblages, consisting of masonry couplets, were subjected to combined shear and axial loading and were laid to failure through monotonic and cyclic loading processes. The efficiency of the different strengthening materials is investigated by comparison with measures obtained for unreinforced assemblages subjected to similar load conditions. The research is aimed at characterizing the contribution of the different strengthening materials and arrangements to increase both the peak shear strength and the residual (post-peak) shear strength. An attempt is made to analytically describe the strengthening effect of reinforcement. For this purpose, two different effects provided by the reinforcing laminates – the increase of friction at the brick–mortar interface and the shear strength of the laminate itself – are considered.