Three-dimensional nonlinear finite element analysis of corroded reinforced concrete beams strengthened by CFRP sheets

This paper investigates how the corrosion process contributes to the reduction of the cross-section, ultimate tensile strength, and ductility of corroded steel reinforcing bars, as well as the bond loss between corroded steel and damaged concrete. Considering such parameters, the finite element models are constructed and validated based on the experimental data obtained from six reinforced concrete (RC) beams into three groups: two control beams, two corroded beams without strengthening, and two CFRP-strengthened corroded beams. The validated model is capable of reflecting the failure mechanism of CFRP debonding that dominates the load-carrying capacity of corroded beams after strengthening. Therefore, the numerical simulations offer a prediction platform for investigating the structural behavior of corroded RC beams strengthened with CFRP (Carbon Fiber Reinforced Polymer) sheets without a new set of experiments. Finally, the results from nonlinear finite element analyses (FEA) help to determine the effect of main parameters affecting the strengthening performance of corroded RC beams, such as concrete compressive strength, longitudinal steel reinforcement ratio, steel/concrete bond strength reduction, flexural strengthening scheme, CFRP length.