Experimental behavior of masonry vaults strengthened with thin extradoxal or intradoxal layer of fiber reinforced lime mortar

The results of a first experimental research program on masonry vaults strengthened by means of glass fiber meshes embedded in a thin layer of lime mortar (Glass Fiber-Reinforced Mortar - GFRM), are herein presented. The tests were designed to reproduce the pattern of a transverse horizontal load proportional to the vault self-weight. The typical simplified loading patterns generally used for the experimental tests concern concentrated vertical loads at the crown section or at 1/4 of the span, but some numerical investigations evidenced that these configurations are not able to reproduce the actual behavior and the effectiveness of the reinforcement. So, a specific rig was designed to apply the horizontal load pattern. Solid brick masonry barrel vaults were considered (thickness 120 mm, arch span 4000 mm, arch rise/radius = 0.75). Three quasi-static cyclic tests were performed: the first concerned an unreinforced vault, the second a vault reinforced with GFRM at the extrados and the third reinforced at the intrados surface with the same technique. The experimental results demonstrated the technique effectiveness and the important increment of ductility of the vaults.