FRP-masonry interfacial debonding: An energy balance approach to determine the influence of the mortar joints

In this paper a close-form relationship between the transferable load at the FRP-masonry interface and the characteristics of the FRP-brick and FRP-mortar interfaces, which are expressed in terms of cohesive material laws, is proposed. Prior to obtaining the aforementioned close-form relationship, experimental evidence is used to highlight that the fracture process at the FRP-masonry interface depends on the characteristics of the constituent materials and the geometry of the masonry. In addition, an analytical procedure previously proposed by the authors, which employs two simplified cohesive material laws for the FRP-brick and FRP-mortar interfaces, is revisited to show that the length of the stress-transfer zone of, and the transferable load at, the FRP-masonry interface vary periodically in accordance with the periodic pattern of bricks and mortar joints.