Composite Reinforced Mortar (CRM) and Fiber-Reinforced Cementitious Matrix (FRCM) for the seismic protection of masonry vaults

Composite Reinforced Mortar (CRM) and Fiber-Reinforced Cementitious Matrix (FRCM) are two modern strengthening techniques for existing masonry, based on the coupling of fiber-based grids and inorganic matrices, applied on the masonry surface. They typically differ for the thickness of the coating (20-40 mm in the former, 8-15 mm in the latter) and the type of embedded reinforcement (pre-coated meshes with wide pitch or dry fabrics with a closer yarns spacing, respectively). To prove their effectiveness in the seismic protection of historical masonry vaulted ceilings, experimental cyclic tests were performed on fullscale thin barrel vault samples subjected to a distributed transversal load. The results are analysed and discussed in the paper: it emerged a good effectiveness of both the strengthening solutions, with significant benefits in both resistance and displacement capacities. Moreover, a key aspect for the reinforcement effectiveness is found in the connection of the composite systems with the abutments. Numerical non-linear static analyses based on a simplified multi -layer approach developed in the OOFEM code allow to analyse the resisting mechanisms and investigate on the reinforcement effectiveness.