Nonlinear analytical solutions for predicting the debonding process of the EBROG FRP-concrete bond

Abstract

Fiber-reinforced polymer (FRP) composites are frequently employed to strengthen reinforced concrete members. The FRP-to-concrete bond established through the externally bonded reinforcement (EBR) technique has consistently been challenging due to the premature debonding of the FRP composite. The debonding process of FRP composites has been significantly postponed due to the implementation of a novel technique known as externally bonded reinforcement on grooves (EBROG) in recent years. Several experimental studies have been conducted to understand the behavior of the EBROG bond. However, a dearth of analytical research has been continued in this field, and closed-form analytical models have not yet been developed. Therefore, this study employs the definition of a nonlinear shear stress-slip relationship to generate and develop analytical models to evaluate the debonding process of the EBROG bond. The presented models have the capability to predict the behavior of the EBROG bond from the start of loading until the final moment of loading. The models' high accuracy is demonstrated by comparing their estimations with the experimental results on longitudinal profiles, load-slip curves, and bond strength. The bond strength model predicts the bond resistance for 90 % of the specimens with an error of less than 20 %. Also, the effect of increasing the number of grooves on the strength and behavior of the EBROG bond is much more pronounced than the effect of increasing the dimensions of the grooves, which is one of the key findings of the parametric study.