Efficiency of FRCM systems for strengthening of masonry walls

The strengthening intervention strategies for structural rehabilitation of existing buildings with composite materials are becoming today very common. Thin composites are ideal for retrofitting buildings in seismic contexts. Their high strength/weight ratio implies a good increase of the strength without adding significant additional masses to the strengthened structure. The Fibre Reinforced Cementitious Matrix (FRCM) materials are spreading as an alternative strengthening technique to the traditional use of the Externally Bonded Fibre Reinforced Polymer (FRP) ones. This research focuses on the study of the ultimate shear capacity of masonry panels strengthened with FRCM materials; in particular, some code formulations are compared with the values of shear forces evaluated with a Finite Element Model (FEM) by interpreting a diagonal compression test. The shear capacity of the un-strengthened panels has been estimated according to the Italian building code, while for the strengthened panels it has been computed according to the recent Italian guidelines for strengthening with FRCM materials. An analysis of the various methodologies frequently adopted for the interpretation of diagonal compression tests, regulated by ASTM and RILEM, has been conducted.