Flexural Behavior of RC Beams Strengthened with Textile-Reinforced UHPC Composite Using End Self-Locking Anchorage and Grooving Techniques

Abstract Textile-reinforced ultra-high-performance concrete (TRUHPC) has emerged as a promising solution for strengthening reinforced concrete (RC) beams; however, its structural efficacy is often compromised by premature interfacial debonding. To address this challenge, this paper proposes a novel hybrid strengthening method that integrates end self-locking anchorages with surface grooving. Four-point bending tests were conducted to evaluate the efficacy of the proposed method. The results show that the proposed strengthening method effectively prevented end debonding and significantly impeded the development of intermediate debonding. The end anchorage system efficiently mitigates stress concentrations by transferring peeling forces from the TRUHPC end into the deep beam core. Concurrently, the grooves expand the effective bond area and reduce peak shear stress at the interface, resulting in a 43.1% increase in debonding load. To complement the experimental findings, finite-element simulations were performed and verified, showing good agreement with test results. The verified model was subsequently extended to perform parametric analysis, investigating the impacts of different strengthening schemes and groove configurations. Finally, an analytical model was proposed to predict the full-range load–deflection response of RC beams utilizing the proposed hybrid strengthening system.