Projections of corrosion and deterioration of infrastructure in United States coasts under a changing climate

Climate change can accelerate infrastructure deterioration in coastal areas because increased temperature and humidity can promote steel corrosion. This study (1) projects corrosion rate changes for reinforced concrete and steel structures in 223 coastal counties, (2) assesses the impact of corrosion rate changes on the useful life of structures, and (3) evaluates direct economic losses due to shortened useful life of highway bridges over the period 2000-2100. The results show that the useful life of concrete structures may decrease by 1.7-2.7% under the representative concentration pathway (RCP) 8.5 and decrease by 0.7-1.1% under RCP 4.5 by the end of the 21st century. The useful life of steel structures may decrease by 7.9-15.9% under RCP 8.5 and 3.3-6.7% under RCP 4.5. Concrete bridges may suffer an average loss of $6.5-11.7/m² under RCP 8.5 and $3.3-16.5/m² under RCP 4.5 due to shortened useful life. Steel bridges may suffer an average loss of $73.4-111.3/m² under RCP 8.5 and $46.9-81.2/m² under RCP 4.5. In both climate scenarios, 10% of counties may have negative losses and 10% of counties may have losses greater than $20 million due to corrosion rate changes for concrete and steel bridges. The results reveal the spatial difference of climate change impacts on infrastructural deterioration and suggest the importance of developing regional specific adaptation strategies.