Reliability of a corroded RC beam based on Bayesian updating of the corrosion model

RC structures degrade primarily due to corrosion-induced damages, mostly by the loss of steel rebar volume. The prediction of time-varying damage due to corrosion is important for assessing the residual life of a structure and making decisions on maintenance/repair. Existing models of prediction fail to provide realistic estimates of steel loss over time. This paper presents a new methodology for the corrosion reliability analysis of reinforced concrete components, where the corrosion loss is estimated employing Bayesian updating using field measurements, which also incorporates instrument biases and errors in the NDT evaluations. Based on compiled experimental results, the updated model provides significantly improved estimation of steel loss over time. Sample reliability analyses over the design life of a corroded RC beam show the importance of updating over the existing model, for both pitting and uniform corrosion considerations.