The bonding strength of GFRP bars embedded within concrete under direct pull-out test

Abstract

Most of the reinforced concrete (RC) structures in the marine environment attacked with corrosion of steel reinforcements that required costly repairs or replacements. The utilization of FRP bars as a non-corrosion material is one of the solutions to increase the durability of RC structures in the marine environment. The innovation of using FRP bars should be developed to improve the quality and reduce the construction cost such as by removing the concrete cover and shear rebar. By removing the concrete cover, the depth of the beam can be minimized without reducing the effective depth of the beam. To substitute the conventional shear rebar, the GFRP sheet strip will be attached to the shear span after concrete hardened. However, the problem is that the bonding area between FRP bars and concrete reduced due to the removal of concrete cover. Therefore, before applying this innovation to the beams' structure, the pull-out test should be conducted in order to clarify this behavior. The influence of the location of FRP bars and the effect of the U-Wrap GFRP sheet on the bond-slip curves will be analyzed. It is expected from this study that the bonding strength between FRP bars and concrete does not reduce significantly and hence, the innovation for constructing RC beams without a concrete cover on the tensile zone can be applied.