Reinforced concrete beams strengthened in shear with NSM CFRP laminates : assessment of influencing parameters

摘要

To appraise the performance of the Near surface mounted (NSM) technique with carbon fiberreinforced polymer (CFRP) laminates for the shear strengthening of reinforced concrete (RC) beamshaving a certain percentage of existing steel stirrups, an extensive experimental research was carriedout. The influence on the effectiveness of the NSM shear strengthening technique of the followingparameters was investigated: the concrete strength; the percentage of existing steel stirrups; thepercentage and orientation of the CFRP laminates. To evaluate the influence, on the strengtheningeffectiveness, of already existing cracks when a beam is shear strengthened with NSM CFRPlaminates, some of the RC beams were pre-cracked prior to their strengthening. A detailed descriptionof the carried out experimental research and a discussion of the obtained results are done in thepresent paper.