Design provisions for FRCM systems bonded to concrete and masonry elements

In this paper, a critical analysis of the available literature on bond tests on masonry and concrete elements externally bonded with FRCM materials was done, firstly. Successively, the collected results were examined in terms of failure mode and maximum strain in order to identify the main geometric and mechanical properties of the reinforcement and the substrate influencing the performance of the strengthening technique. Regression analyses were, thus, carried out on the collected experimental results, separately for concrete and masonry elements, in order to asses reliable formulations predicting the maximum strain in function of the axial stiffness of the reinforcement, the mechanical properties of the substrate, and the experimentally observed failure modes. Basing on the average provisions of the maximum strain in the FRCM reinforcement, characteristic values were also assessed according to a 'design by testing' procedure.