Predictive Framework for FRP-Concrete Corrosion Repair

Fiber-reinforced polymers (FRPs) have been used for repairing chloride-induced corrosion in steel for more than 40 years. Since FRP is a barrier element, it cannot stop electrochemical reactions responsible for corrosion of steel in concrete. The effect of ongoing corrosion can only be detected by inspectors after it has reached such an advanced state that rust stains become visible. This paper presents a predictive framework to estimate the rate of chloride-induced corrosion inside an FRP-concrete repair. Statistical methods were used to extend experimental data on oxygen permeation for one- and two-layer configuration to multilayer configurations. The model was calibrated by comparing its prediction against measured metal loss in specimens repaired using one to four FRP layers that were kept outdoors and subjected to simulated tidal cycles for longer than three years. The application of the model is illustrated by a numerical example.