RETROFIT OF MASONRY BUILDINGS WITH CRM - COMPOSITE REINFORCED MORTAR - SYSTEM: PRACTICAL DESIGN CONSIDERATIONS ABOUT SEISMIC CAPACITY

Abstract

Ancient masonry buildings are characterized often by a high seismic vulnerability: innovative intervention strategies for strengthening, based on the use of FRP composite materials are gradually spreading. In particular, the coupling of FRP preformed elements (meshes, angles and connectors) with mortar layers (Composite Reinforced Mortar techniques - CRM) evidenced a good physical, chemical and mechanical compatibility with the historical masonry and experimental campaigns proved to be effective for the enhancement of both in-plane and out-of-plane performances of masonry, contrasting the opening of cracks and improving both resistance and ductility. The resistant mechanisms that are created in CRM reinforced masonry walls subjected to in-plane horizontal actions are analyzed in the paper and a practical design approach to evaluate their performances is illustrated, evidencing the dominant collapse mode at the varying of the masonry characteristics. Some masonry walls are analyzed numerically and analytically, as “case study”.