Effect of confinement on the behavior of FRP straight anchors

The use of Fiber Reinforced Polymer (FRP) materials in combination with the Externally Bonded Reinforcement (EBR) method is a strengthening system (EBR-FRP system) that is commonly deployed to increase the load carrying and/or ductility capacity of structural members. One of the main drawbacks of EBR-FRP systems is premature debonding, which entails the debonding of the FRP reinforcement from the substrate at a strain level that is typically a small fraction of the rupture strain. In order to prevent or delay premature debonding, FRP anchors have proven to be a suitable solution to prevent the delamination of FRP materials from the concrete substrate when the Externally Bonded Reinforcement (EBR) method is used by ensuring continuity of the load path from the FRP sheets into the structure or improving the FRP-to-concrete bond strength. On the other hands, one of the phenomena that could affect the behavior of FRP anchors is the concrete confinement. Hence, the research here presented aims to comparing test results for a single FRP anchor in confined and unconfined configurations to establish a ratio between the confined and the unconfined bond strengths. Subsequently, Results are discussed and compared with theorical studies.