A Spatial Assessment of Corrosion Initiation Risks of Bridge Decks Across North America

The temperature and humidity are recognized as the major environmental drivers that increase corrosion risks of reinforced concrete (RC) bridge decks under chloride ingress. The report released by the Intergovernmental Panel on Climate Change (IPCC) in 2021 sounded an alarm again on the ‘irreversible’ climate change impact. This study conducts a holistic spatial assessment of corrosion-induced damage risks for RC bridge decks across North America. The areas with cold winter, where chlorides come from de-icing salts, were classified into 16 climate regions. For each region, 30 representative bridge locations were selected to perform a spatial time-dependent reliability analysis to quantify corrosion damage risks of RC bridge decks under both historical and future climate scenarios. The analysis results formed a data collection for training artificial neural network (ANN) models, which were subsequently incorporated with the coordinated regional climate change projection to unveil the relationship between climate data and the concerned corrosion damage index for bridge decks across North America. Finally, a series of corrosion risk maps were generated to reveal the spatial patterns of corrosion initiation risks. The likelihood of corrosion initiation of bridge decks by 2100 varied considerably by region, from nearly 0% for the northern areas to 92.1% for the south. In general, the decks in northern regions were more strongly impacted by climate change than those in southern regions due to the more notable change in climate conditions. The outcomes will assist transportation agencies to make informed decisions for bridge management with consideration of future climates.