Seismic enhancement of masonry buildings strengthened through GFRP reinforced mortar coating

The reduction of seismic vulnerability of existing masonry buildings through the application on the walls of a mortar coating reinforced with a GFRP (glass fiber reinforced polymer) mesh is studied and discussed. Numerous experimental tests, carried out by the authors, demonstrate the effectiveness of this technique for enhancing the mechanical response of the walls, both subjected to in-plane and out-of-plane actions. In the study, the capacity curves of an existing unreinforced masonry building are compared with those of the same building strengthened with the GFRP reinforced mortar coating technique. An almost regular two storey building is considered in the numerical study and it is analyzed by adopting the method of the equivalent frame. Two different types of masonry are considered in the study: solid bricks and rubble stones. Static nonlinear analyses are carried out and the nonlinearity of the material of the wall elements (piers and spandrels) is considered through the introduction of plastic hinges in the plane of the masonry wall. The results evidence a significant increase in terms of shear resistance, displacement capacity and total strain energy. The collapse due to bending of piers in most cases of strengthened buildings occurred before than the ultimate shear drift was obtained.