Investigation of Near Surface–Mounted Method for Shear Rehabilitation of Reinforced Concrete Beams Using Fiber Reinforced–Polymer Composites

Abstract

This paper presents the results of an investigation of reinforced concrete (RC) T-beams retrofitted in shear with near-surface mounted (NSM) fiber-reinforced polymer (FRP) rods. Six full-scale 4,520-mm-long RC T-beams were tested to study the effects of important parameters such as the presence of NSM FRP rods, the presence of steel stirrups, and the steel stirrup ratio. This paper provides an insightful and comprehensive description of the behavior of strengthened T-beams under increasing load, from the formation of the first crack to ultimate failure. The results of this study and those gathered in the presented database show that existing steel stirrups and strengthening NSM FRP did not diminish each other’s effect when failure modes unrelated to shear resistance of RC beams were prevented. The experimental results of this study and those in the database were used to verify a newly proposed model to predict the shear contribution of NSM FRP rods and laminates in RC beams strengthened in shear. The proposed model showed an improved accuracy compared with the existing models in the literature.