Probability based chloride diffusion model to predict the condition states of RC bridge elements

This paper presents a probability-based model to assess the deterioration of reinforced concrete elements due to chloride ingress. The aim of the model is to estimate the lifetime of bridge components incorporating the time to corrosion initiation, crack initiation and crack propagation models. The model is based on probability distribution of chlorides, concrete types and cover to reinforcement of the bridge elements in a particular region under consideration. The analysis is based on time varying diffusion parameters, which gives better results than the commonly used simplified error function formula. The crack initiation and propagations are then related to the condition states defined by VicRoads bridge inspection manual. The results are compared with the actual inspection data of the bridge components made available from VicRoads. The comparison demonstrates that the future condition states of the bridge components can be estimated using the chloride diffusion model presented in this paper