Near surface mounted CFRP-based technique for the strengthening of concrete structures

摘要

To assess the effectiveness of the Near SurfaceMounted (NSM) strengthening technique, an experimentalprogram was carried out involving reinforced concrete (RC)columns and beams. In columns failing in bending thepresent work shows that the failure strain of the CarbonFiber Reinforced Polymer (CFRP) laminates can beattained using the NSM technique. Beams failing inbending were also strengthened with CFRP laminates inorder to double their load carrying capacity. This goal wasattained and maximum strain levels of about 90% of theCFRP failure strain were recorded. Performance ofexternally bonded reinforcing (EBR) and NMS techniqueswas compared for strengthening RC beams failing in shear.NMS was much more effective, not only in terms of theincrease of the load carrying capacity and deformability atbeam failure, but also with respect to the time consumingnature of the corresponding strengthening procedures. Toassess the bond behavior of CFRP to concrete, pulloutbendingtests were carried out. The influences of bondlength and concrete strength on the bond behavior wereanalyzed.