Effects of the bond properties of ETS‐GFRP bar to concrete on the shear behavior of ETS‐GFRP‐strengthened RC beams

Abstract

This study numerically investigates the effects of bond properties between embedded through‐section‐glass fiber‐reinforced polymer (ETS‐GFRP) bars and concrete on the performance of the reinforced concrete (RC) beams strengthened in shear with ETS‐GFRP bars. The key bond parameters, including the interfacial fracture energy (Gf), bond stiffness (K), and bond strength (τm) are examined. Results demonstrate that the bond properties of ETS‐GFRP bar–concrete interfaces mainly affect the postpeak behavior and ductility of the ETS‐strengthened beams. The FE model considering triangle bond model for the ETS‐GFRP bar–concrete interfaces can reasonably predict the load versus deflection and failure mechanism of the ETS‐strengthened beam as well as the debonding process of the ETS‐GFRP bars from concrete against the experimental results. The use of the flexible and ductile adhesive, which has small bond stiffness and high interfacial fracture energy, for ETS‐GFRP bonding technology would lead to the large ductility of the ETS‐GFRP‐strengthened beams. The ETS‐GFRP bar–concrete interfaces with high cohesive strength can distribute the shear cracks and limit the local debonding, encouraging the deformability of ETS‐GFRP‐strengthened beams.