Damage risks and economic assessment of climate adaptation strategies for design of new concrete structures subject to chloride-induced corrosion

• Climate change combined with chloride ingress reduce RC durability significantly.
• We studied the cost-effectiveness of two climate adaptation measures.
• The cost-effectiveness is evaluated in terms of the benefit to cost ratio (BCR).
• The BCR analysis should include time-dependent damage risks due to climate change.
• The BCR depends on the type of component, exposure and climate change scenario.

Reinforced concrete (RC) structures are subject to environmental actions affecting their performance, serviceability and safety. Among these actions, chloride ingress leads to corrosion initiation and its interaction with service loading could reduce its operational life. Experimental evidence indicates that chloride ingress is highly influenced by weather conditions in the surrounding environment and therefore by climate change. Consequently, both structural design and maintenance should be adapted to these new environmental conditions. This work focuses on the assessment of the costs and benefits of two climate adaptation strategies for new RC structures placed in chloride-contaminated environments under various climate change scenarios. Their cost-effectiveness is measured in terms of the benefit-to-cost ratio (BCR) and the probability that BCR exceeds unity – i.e., Pr(BCR > 1). It was found that increasing concrete strength grade is more cost-effective than increasing design cover. The results also indicate that the cost-effectiveness of a given adaptation strategy depends mainly on the type of structural component, exposure conditions and climate change scenarios.