Quantification and propagation of uncertainties of a bond model for corroded reinforcement in structural analysis

Abstract

The modelling of bond behavior can be an important aspect in the reliability assessment of corroded reinforced concrete structures. However, existing models for bond properties of corroded reinforcement - to our knowledge - are not expressed in probabilistic terms and hence not considered in reliability analyses. This paper aims to fill this gap by (i) quantifying the uncertainties associated with a selected model that translates a reinforcing bar area loss to the change in bond-slip properties; and (ii) propagating these uncertainties to structural reliability to assess their importance. The frequentist paradigm is applied for the statistical analysis of experimental data for the bond model of corroded reinforcement proposed in the literature. Reliability assessment of an illustrative example - a simply supported beam with lap splices - is completed with and without considering the uncertainties in this bond model. The reliability calculations concern ultimate limit state verifications, using non-linear finite element analysis. The results show that the neglect of uncertainties in the bond model for corroded reinforcement can lead to about 10 times underestimation of the failure probability, hence their consideration in reliability assessment is advised.