Impact of Corrosion on seismic response of reinforced concrete structures in severe exposure conditions Environment

Reinforced concrete elements experience corrosion, especially due to the chemical phenomena of carbonation and chloride ions diffusion and penetration. The worst consequences are related to the spalling of concrete covers, resulting in a decrease of the elements resistance and structural performance. The object of this study is to investigate how the overall behaviour of the structure could be affected by development of corrosion induced damage even on just a limited number of structural elements. This work considers the case study of a water treatment plant located in Genoa, in a severe expo-sure environment. Five different possible corrosion scenarios for the reinforcement of structural elements have been hypothesized and numerical analyses have been conducted assessing the response of the damaged structural schemes under seismic actions characterized by different return periods. The results highlighted that, due to corrosion, redistribution of internal actions even up to 20% higher than in the uncorroded state are likely to happen, thus affecting the safety margin for the Ultimate Limit States as well as the likeliness of attainment of a Serviceability Limit State and confirming the importance of implementing this kind of approach into a durability based esign of critical infrastructures under accidental actions.