Structural weakness or overloading, dynamic vibrations, settlements, and in-plane and out-of-plane deformations can cause the failure of unreinforced masonry (URM) structures. In the case of overstressing, these buildings have features, such as unbraced parapets, inadequate connections to the roof, floor, and slabs, and the brittle nature of the URM elements, that can threaten human lives. Obviously, there is an urgent need for the development of effective and affordable retrofitting techniques for masonry elements.
Externally bonded fiber reinforced polymer (FRP) laminates and bars have been successfully used to increase the flexural and/or the shear capacity of reinforced concrete for retrofitting of the civil infrastructure. FRP composites also can provide solutions for the strengthening of URM walls subjected to in-plane and out-of-plane overstresses caused by high wind pressures or earthquake loads. Available test results show that each potential failure cause of URM walls is prevented and/or lessened by using FRP composites.