Study on behaviour of corroded RC beams repaired in shear with NSM CFRP rods

Abstract

The near surface mounted reinforcement technique (NSM) is one of the promising techniques used nowadays. In the NSM technique, the Carbon Fibre Reinforced Polymer (CFRP) rods are placed inside pre-cut grooves and are bonded to the concrete with epoxy adhesive. Experimental results obtained on concrete short beams taken from one beam exposed to a natural corrosion for 25 years then repaired only in flexion or in flexion and shear are reported. Results were compared to control beams. One 6-mm-diameter NSM CFRP rod is used to repair the beams. The beams were tested statically in three-point bending up to failure. Results showed that the failure mode of all repaired RC beams in flexion was by shear failure after CFRP rods slip. But the failure mode of the corroded RC beams repaired in both flexion and shear occurred due to concrete crushing. An increase was noticed in the ultimate shear capacity of those repaired beams.