Interfacial Fracture Properties of FRCM Composites Bonded to a Quasi-Brittle Material

Newly-developed composites that employ cementitious, i.e. inorganic, matrices have gained a momentum in the last decade in an attempt to overcome some drawbacks related to fiberreinforced polymer (FRP) composites. This broad category of composites is referred to in the literature as fiber-reinforced cementitious matrix (FRCM) composites or textile reinforced mortar (TRM) composites. The premature debonding of FRCM composites remains a critical issue as it is for FRPs and the phenomenon is even more complex than what observed in FRP materials because a hierarchy of interfaces exists as the fibers might debond from the inorganic matrix as well as the entire composite might debond from the substrate. This paper is a preliminary study that aims at investigating the feasibility of employing optical fibers to measure the strain in the fibers of the FRCM system. The research focuses on one FRCM that is comprised of a cement-based mortar and steel fibers. FRCM strips are bonded to concrete to study their bond behavior using a single-lap shear setup. The readings of the optical fibers are compared with the experimental strain derived from the applied load to understand if optical fibers can be used to understand the stress transfer between the steel fibers and the matrix.