A Novel Analytical Bond Model for ETS FRP Bars in Shear Rehabilitation of Concrete Members

In this article, an unprecedented fracture mechanics-based bond model for embedded through-section (ETS) fibre-reinforced polymer (FRP) bars installed in concrete blocks is proposed. Various methods have emerged for rehabilitating substandard and deteriorated concrete structures. The ETS FRP bar method provides numerous advantages over existing shear strengthening methods, but no reliable and comprehensive bond-slip model exist to predict the method's bond behaviour. In this study, a state-of-the-art analytical bond model is derived for determining the debonding force of the ETS FRP bars from concrete blocks using a newly proposed bi-linear bond-slip relationship that is expressed as a function of the maximum shear stress and its corresponding slip. The accuracy of the results predicted by the proposed model is verified with the existing push-pull data of ETS FRP/concrete joints in the literature. The results show that the newly proposed model can be used for both carbon FRP (CFRP) and glass FRP (GFRP) ETS bars with an average Pexp/Pmax ratio of 1.04 with superior statistical accuracy measures when compared to the existing bond models' predictions.