Experimental calibration of the bond strength of FRP, externally glued on masonry elements, based on design provisions

The present work deals with experimental calibrations of the coefficient that correlates interface fracture energy and mechanical properties of the substrate and, therefore, allows to estimate the design axial force of the reinforcement. Such a coefficient, due to a lack of experimentations at the time those Guidelines were released, was evaluated as half the corresponding one in the case of concrete substrate. Herein presented calibrations are based on the collection and analysis of shear tests, available in literature, performed on masonry elements, such as clay bricks and natural stones, and on masonry prisms.