Sustainable maintenance and repair of RC coastal structures

Many agencies worldwide have to manage structurally damaged reinforced concrete (RC) coastal infrastructure subjected to chloride ingress that require significant repairs. These repairs should ensure optimal levels of serviceability and safety and minimise costs and environmental impact. However, there is a wide range of protocols, techniques and materials for repair and there is not much information about their durability performance. This paper proposes a methodology for evaluating, comparing and/or improving the sustainability of maintenance strategies. It was developed within the framework of the Mareo project in collaboration with the different stakeholders involved during the whole structural lifetime. It is based on probabilistic modelling of deterioration and repair, and the sustainability assessment considers costs (with conventional and intergenerational discounting), carbon dioxide emissions and waste generation. The methodology is illustrated with a numerical example aiming to evaluate and improve the sustainability of a repair technique for RC structures subjected to chloride-induced corrosion damage. Overall results indicate that sustainable solutions increase global costs but they could significantly reduce environmental impact.