Study on local effects of aggressive environmental conditions on masonry strengthened with FRCM

Aggressive environmental conditions as moisture, temperature and presence of salts, may affect the interfacial behaviour of FRCM bonded to masonry. To check the effectiveness of intervention solid clay brick samples and masonry assemblages including mortar joints were investigated. Strips of carbon fibre nets were applied with a cementitious or a lime based matrices. Specimens were exposed to salt crystallisation tests, according to a RILEM procedure, and to thermal cycles with a temperature variation ranging between -10°C and +70°C. The characteristic size of damage of the samples were monitored by visual observation and laser profilometer; the loss of bond of the composites was verified by pull-off test. Tests results showed different behaviour between the inorganic matrices applied on bricks having different strengths. Moreover, the adhesion strength was affected by the presence of bed joints. The adherence of the specimens of cement matrix depends from the type of substrate and his damage. Specimens of lime matrix do not seem to have a relation between damage of the substrate and adherence, as the failure occurred at the interface matrix/strengthening.