Modelling uncertainties for the loadbearing capacity of corroded simply supported RC beams

The probabilistic assessment of structures damaged by corrosioncalls for deterministic models of the degradation of the structuralperformance and probabilistic models accounting for the uncer-tainties in material properties, geometry and models used in thereliability analysis. This paper describes the development of aprobabilistic model of the uncertainties that arise from the pre-diction of the loadbearing capacity of reinforced concrete struc-tures damaged by corrosion of the reinforcement. The investiga-tion focuses on the flexural failure of simply supported beamssuffering from chloride-induced corrosion. The loss of steelcross-sectional area, the reduction in strength and ductility of thecorroded bars, the loss of bond between reinforcement and con-crete and the cracking of the concrete cover are taken into ac-count in a non-linear finite element analysis. The comparison be-tween experimental results and numerical predictions of thefailure load allows the quantification of the model uncertainty ac-cording to the framework proposed by the Joint Committee onStructural Safety. A Bayesian updating methodology is proposedto account for prior knowledge and experimental results.