Urban scale mapping of concrete degradation from projected climate change

• Corrosion depths may exceed the ACI suggested clear cover in 65–70 years.
• Chlorination-induced corrosion is more rapid than carbonation for a coastal city.
• Geospatial analysis allows for building-specific assessment of vulnerability.
• Regional climate adaptation through design code adjustment and protective technologies is recommended.

Anthropogenic increases in atmospheric greenhouse gas (GHG) concentrations and resultant changes in climate will have significant detrimental effects to urban infrastructure, from both extreme events and longer-term processes. Here we investigate impacts to concrete structures due to enhanced corrosion through increases in carbonation and chlorination rates. High and low emission scenarios (IPCC A1FI and B1) are used in combination with downscaled temperature projections and code-recommended material specifications are used to model carbonation and chloride-induced corrosion of concrete structures in the Northeast United States. The results suggest that current concrete construction projects will experience carbonation and chlorination depths that exceed the current code-recommended cover thickness by 2077 and 2055, respectively, well within the lifetimes of these buildings, potentially requiring extensive repairs. Geospatial modeling in the Boston metropolitan area is used to project building and block-level vulnerability of urban concrete structures to future corrosion, and related maintenance needs, and to project cover thickness degradation for the existing building stock. The methods described here can be used for city-specific modeling of long-term climate impacts on concrete infrastructure and provide a scientific basis for future-oriented construction codes.