Bond‐slip behavior between polypropylene fiber concrete and corroded reinforcement

Abstract In this paper, the bond‐slip behavior and bond‐slip constitutive model of corroded reinforcement embedded in polypropylene fiber‐reinforced concrete (PFRC) were investigated. The central pullout test was conducted for 36 specimens. The effects of the corrosion level of reinforcement and the volume fraction of polypropylene (PP) fibers in concrete on the damage mode and bond‐slip process between reinforcement and concrete were studied. Based on the experimental data, a modified bond‐slip constitutive model considering the corrosion level of reinforcement and the volume fraction of PP fibers in concrete was proposed, and the proposed modified bond‐slip constitutive model was used in finite element analysis. The results showed that the addition of PP fibers effectively improved the ultimate bond strength, peak slip and bond toughness of reinforcement and concrete. The enhancement of the bonding properties of the specimens by the PP fibers remained significant after the reinforcement was corroded. The proposed modified bond‐slip constitutive model agreed well with the experimental results. The validity of the proposed model was further verified by finite element analysis.