Bond of FRP rods in damaged RC beams strengthened with NSM technique

In strengthening reinforced concrete (RC) elements with composite materials, the role of adherence between concrete and FRP assumes great importance as it guarantees the effectiveness of the consolidation method. In this paper the bond mechanisms between FRP rods and concrete second the Near Surface Mounted (NSM) technique have been analyzed by experimental results of investigation and a theoretical linear model. The experimental investigation consists of direct pull-out tests on RC elements with circular GFRP and CFRP rods inserted into a groove. Through pull-out tests main parameters of bond have been presented. The experimental results are compared with those obtained by the theoretical model.