Diffusion-Based Service Life Modeling to Predict Chloride Contamination and Damage in Bridge Decks: Validation Case Studies

Abstract Bridge decks exposed to de-icing agents and marine environments often deteriorate due to chloride-induced corrosion. Investigations characterizing current condition and expected future durability are critical to facilitating appropriate selection and timing of rehabilitation actions. These investigations can be most effective if based on thorough field assessments supported by probabilistic service life modeling. Two such investigations of reinforced concrete bridge decks, located in the Midwest-Region of the United States, are presented as case studies; one located in Indiana and another in Illinois. For each case study, field assessment and material testing were performed in the early 2010’s, and then a follow-up assessment was performed in the early 2020’s (studies performed roughly ten years apart). The investigations included evaluations of changes in chloride contamination at the surface and through the cover concrete, and of damage propagation rates relative to field measurements. The findings show that chloride diffusion modeling is an effective tool for predicting chloride ingress and associated damage rates. The findings also highlight the importance of characterizing variability in bridge conditions during modeling efforts.