Speaker
Description
Strengthening of reinforced concrete (RC) structures is crucial for extending service life and enhancing structural performance. Fiber-reinforced polymers (FRP) have been widely adopted for this purpose, especially for the shear and flexural strengthening of RC beams. In practice, flexural strengthening is often accompanied by the need of shear strengthening to ensure that damage is prioritized and ductility is maintained. Although externally bonded FRP sheets have proven effective in both applications, their performance is often compromised by premature debonding, which limits their strengthening efficiency. Recent studies have demonstrated that anchoring FRP sheets can delay or prevent debonding, thereby improving the overall performance of the strengthening system. However, the study of FRP sheet anchoring remains insufficiently explored in both shear and flexural applications. Further, the combined effect of these strengthening mechanisms has received limited attention.
This study investigates the effectiveness of using FRP rope as anchorage of FRP sheets in both shear and flexural strengthening through large-scale T-beam specimens subjected to four-point bending. Shear strengthening was implemented using two novel closed-form FRP methods, either through FRP sheets anchored with FRP ropes to form a closed form strengthening or using NSM FRP ropes as standalone shear reinforcement—while flexural strengthening was achieved with externally bonded FRP sheets anchored with FRP rope spike anchors. The experimental results indicate that the use of anchorage significantly delays or even prevents debonding, leading to an enhanced structural response. Moreover, the interaction between the shear and flexural strengthening mechanisms was found to influence the overall failure behavior. To gain deeper insights into crack propagation and stress distribution, a supplementary finite element analysis (FEA) was conducted, offering valuable guidance for optimizing FRP-based retrofit strategies in RC structures.
