Towards a methodology for estimating strength and collapse mechanism in masonry arches strengthened with fibre reinforced polymer applied on external surfaces

Assessment of the effects of the application of advanced materials and new technologies on traditional structures has assumed a major relevance within the ongoing debate on the preservation of historic buildings. The aim of the present paper is to discuss the validity of analytical models, by means of experimental investigations carried out on masonry arches reinforced with CFRP strips, bonded at the intrados or extrados with distinct configurations. A theoretical prediction of ultimate strength for the different reinforcement configurations was derived in agreement with the occurrences observed during the experiments (masonry crushing, FRP rupture, debonding, sliding along the mortar joint). The results of the experimental trials allowed not only to validate the proposed analytical derivations but also to evaluate the impact of different reinforcement configurations on the strength of masonry arches and then to deduce considerations on sizing criteria for the CFRP strengthening of traditional masonry structures.