Corrosion-Induced Serviceability Risks for Bridge Decks in a Changing Climate

Chloride ingress is among the principal causes of corrosion in reinforced concrete (RC) bridge decks, impairing their durability and serviceability. Climate change is expected to alter the environmental factors (e.g., temperature and relative humidity) that are known to influence the corrosion process, creating additional uncertainties in the long-term performance of RC decks. This study aims to tackle this issue by quantifying the corrosion-induced damage under a changing climate. To accomplish this objective, a spatial time-dependent reliability method is used to calculate the probability and extent of corrosion-induced cover cracking to RC bridge decks. Random field method and Monte Carlo simulation (MCS) are used to model the spatial variability of structural and material parameters, and exposure conditions of the bridge deck, as well as the inherent randomness associated with deterioration. The proposed methodology is then illustrated using a numerical example that calculates the corrosion-induced damage for bridge decks, in terms of probability of corrosion initiation, and the probability and extent of concrete surface cracking on the top of the deck. Analysis results are compared for historical and future climate scenarios and for two Canadian cities characterized by different weather and exposure conditions (an inland area with cold winter and a coastal area, where chlorides come from de-icing salts and salt spray, respectively). Compared to the case with climate change effects incorporated, using historical climate data results in an overestimation of up to 14.3, 13.7 and 10.8% for the time to corrosion initiation, time to crack initiation, and service life, respectively.