Shear strengthening of reinforced concrete beams with near-surface mounted fiber-reinforced polymer rods

The use of near-surface mounted (NSM) fiber-reinforced polymer (FRP) rods is a promising technology for increasing flexural and shear strength of deficient reinforced concrete (RC) members. As this technology emerges, the structural behavior of RC elements strengthened with NSM FRP rods needs to be fully characterized. Eight full-size beams (two control beams and six strengthened beams) were tested Carbon FRP deformed rods were used for shear strengthening. The variables examined in the shear tests were spacing of the rods, strengthening pattern, end anchorage of the rods, and presence of internal steel shear reinforcement. Performance of the tested beams and modes of failure are presented and discussed in this paper The test results confirm that NSM FRP rods can be used to significantly increase the shear capacity of RC elements, with efficiency that varies depending on the tested variables. Results of the experimental tests are compared with the predictions of a simple model, showing reasonable agreement.