Experimental behaviour of masonry vaults strengthened by innovative composite materials

In this paper, the results of an experimental investigation on full-scale masonry vaults, strengthened at the extrados with different composite materials, is presented. Eight vaults were built with low strength brick and lime mortar to obtain mechanical characteristics as similar as possible to existing elements. Five reinforced systems were tested: steel fibres and basalt net, applied with a lime mortar matrix (SRG and BTRM), steel reinforced polymer and carbon fibres reinforced polymer (SRP and CFRP) and extrados stiffening diaphragms (‘frenelli’) reinforced with SRP and SRG. Two reference vaults, unstrengthened and reinforced with SRG strips, were tested under monotonic vertical loads, applied at the quarter of the span. Six reinforced vaults were tested under cyclic vertical loads, alternately applied at the quarters of the span. Results of tests carried out allowed comparing the global behaviour of the various specimens and the influence of the type of reinforcement (fibre -steel, basalt and carbon, and matrices -organic and inorganic). In addition, modal identification analysis was performed at incremental steps during the tests, to find correspondence between dynamic behaviour and damage state of the vaults.