Flexural behavior of the corroded RC beams strengthened with BFRP grid-reinforced ECC

Abstract

In marine environment, the reinforced concrete (RC) used in offshore structures is subjected to significant erosion by chloride ions, resulting in severe degradation of its mechanical performance. Therefore, it is essential to employ appropriate strengthening techniques to enhance the mechanical properties of such corroded components. To assess the effectiveness of these strengthening techniques, this study investigated the flexural behavior of corroded RC beams strengthened with Basalt Fiber Reinforced Polymer (BFRP) grid-reinforced Engineered Cementitious Composite (ECC). A series of numerical models were developed and their accuracy was verified through experimental results. Subsequently, the contributions of various components to flexural capacity, stress distribution, and the neutral axis position at different stages were investigated through numerical analysis. Additionally, the impact of key parameters on the flexural capacity of the hybrid beams was discussed. Finally, a theoretical model was proposed to predict the moment-displacement curves of the hybrid beams. The results showed that, at the point of hybrid beam failure, the stress within the BFRP grid reached 50%–70% of its maximum tensile stress. As the cross-sectional area of the BFRP grid increased, it effectively delayed the failure caused by tensile stress in the hybrid beam. The theoretical model successfully predicted the moments of the hybrid beams at three feature points.