Ancient masonry arches and vaults strengthened with TRM, SRG and FRP composites: Experimental evaluation

Composite materials made with textile fibers both with polymeric and cementitious matrices are often adopted for the retrofitting of masonry arches and vaults. A specific project that analyzes the performance of ancient masonry arches and vaults strengthened with composite systems has been recently concluded at Politecnico of Milan. The project involves the experimental evaluation and the development of numerical and analytical simulations. In this paper the experimental campaign is described, whereas the numerical validation is provided in an accompanying paper (Bertolesi et al., 2017). The tests were performed in situ on ancient masonry arches and vault elements. In particular, three barrel vaults and two arches either unreinforced or reinforced with Steel Reinforced Grout (SRG), Textile Reinforced Mortar (TRM) and Fiber Reinforced Polymer (FRP) were tested. The arches had a span equal to 3.30 m, a rise equal to 0.83m and were built with common Italian bricks regularly spacing out two bricks laid edge on (thickness of the arch 12 cm) with two bricks (one over the other) disposed in single leaf. Barrel vaults had the same geometry of the arches but were made with a single leaf. In all cases, an eccentric vertical load was applied at 1/4 of the span and was increased up to failure. The experimental results on unreinforced structures are compared with those obtained on the strengthened ones in terms of failure mode, maximum load, stiffness and ductility.