SRP/SRG Strips Bonded to Concrete Substrate: Experimental Characterization

Steel reinforced polymer (SRP) and steel reinforced grout (SRG) systems have recently gained popularity in the field of external strengthening and repairing of existing structures. They consist of composite materials made of high strength steel cords embedded in polymeric or inorganic matrices and applied to the structural member via wet lay-up. Experimental studies have frequently shown the potentials of these innovative composite systems in improving the performance of concrete and masonry structures. However, additional studies are required to expand the existing knowledge and to develop specific design guidelines. The present paper contributes to filling some of the foregoing knowledge gaps by discussing the experimental results of 50 direct single-lap shear tests performed to investigate the bond behavior between SRP/SRG reinforcement and concrete substrate. Useful considerations are provided in terms of failure mode, bond strength and effective bonded length of the SRP/SRG strips based on the variability of the following main parameters: density of the steel fabric, bonded interface length, number of layers composing the strip, and width of the bonded strip.