Compressive behaviour of brick masonry panels strengthened with CFRP bed joints reinforcement

The study investigates the compressive behaviour aspects connected to the application of the bed joints reinforcement technique performed with CFRP (carbon fibre reinforced polymer) thin strips. The intervention technique can be particularly suitable in counteracting the typical damaging phenomenon of massive brick masonry structures, which is denoted by diffused thin vertical cracks (creep behaviour). The intervention consists in embedding the strips into pre-grooved mortar joints, and repointing them with a suitable hydraulic lime based mortar. Experimental laboratory tests were carried out on selected materials constituting the wall samples (solid clay bricks and lime-based mortars) and the reinforcing materials. In particular, according to the requirements of durability, compatibility, low obtrusiveness, and structural performance optimization, a hydraulic lime-based mortar as embedding product and a flexible CFRP thin strip, having a rectangular cross section 5×1.5mm, were used. In the paper, the results obtained by monotonic compression tests on brick masonry panels in plain, strengthened and repaired conditions after pre-damage are compared. Moreover, the main results of a series of laboratory pseudo-creep compression tests carried out on brick masonry panels strengthened with CFRP thin strips are presented and compared with those obtained from standard compression tests.