Discussion of “Pull-out test and discrete spring model of fibre-reinforced polymer perfobond rib shear connector”

Abstract

The discussed paper presented a series of pull-out tests for fibre-reinforced polymer (FRP) perfobond rib shear connector and proposed a discrete spring model to investigate the connector's shear behavior. The discussers appreciate the author's meaningful work. Some findings are interesting to the discussers and are worthy of further discussion. The statement that “the ultimate load caused by the failure of concrete dowel increases with larger areas of the rib hole and a larger number of the rib holes” and the conclusions that “the resistance produced by concrete dowel action was practically linearly proportional to the area of the rib hole” and “the resistance of concrete dowel action was not directly proportional to the number of the rib holes and experienced slight loss for a larger number of rib holes” are useful and can be introduced to near surface mounted (NSM) FRP strips for the strengthening of reinforced concrete (RC) beams (Bianco et al. 2009). According to this thought, if we make some holes on the FRP strips, the resistance may be improved greatly. It is worthy of further study. The predicted ultimate load by FRP failure is calculated by the following equation in the discussed paper.