Experimentally optimized anchored-FRP method: A high-strength, cost-effective and ease-to-install technique for concrete rehabilitation

Conventional EB-and NSM-FRP techniques tend to prematurely fail in FRP delamination, suggesting inefficient utilization of the FRP materials. Various anchorage systems have been developed by integrating FRP anchors with FRP patches or groove bond to maximize the utilization of FRP materials. This study proposes a simpler but robust method that can make full use of FRP materials while minimizing the need for groove excavation, FRP patches, epoxy adhesive and surface preparations. The reinforcement was achieved by externally bonding FRP reinforcement to the concrete surface, with bent anchors being embedded into the strengthened elements. 51 experiments were conducted to demonstrate the potentials of the proposed method, which successfully prevented premature debonding failure, thereby offering robust rehabilitation solutions with a reduction of up to 42 % in epoxy usage compared to current methodologies. The results also suggested the impact of key parameters, such as cross-sectional area, embedment depth, and multi-reinforcement arrangement, on the effectiveness of the proposed FRP technique. Based on the experimental findings, discussions and recommendations were presented to facilitate the continued advancement of the proposed FRP methodology, aiming to fully develop FRP strength and minimize the need for FRP materials and epoxy adhesive in comparison to the current anchored FRP methods.