Preliminary assessment of durability of sustainable RC structures with mixed-in seawater and stainless steel reinforcement

The massive use of natural resources such as fresh water or virgin rock for aggregates in the construction industry originates the need for possible alternative solutions aimed at the environmental sustainability, as, for instance, the use of chloride-contaminated raw materials for the production of concrete. In the framework of a research project financed by the Infravation Program (Advanced systems, materials and techniques for next generation infrastructure), an experimental study is undertaken aiming at demonstrating the safe utilization of seawater and salt-contaminated aggregates (natural or recycled) for a sustainable concrete production when combined with noncorrosive reinforcement to construct durable and economical concrete infrastructures. Considering the lack of sufficient fresh water in many regions of the world, this paper focuses on a preliminary evaluation of the possibility of replacing fresh water used to mix/cure concrete with seawater, combined with different types of stainless steel reinforcement. Based on literature data and the performance-based approach of "Model Code for Service Life Design" published by the International Federation for Structural Concrete (fib), risks associated with the use of using seawater in relation to the service life a reinforced concrete element in a marine environment are investigated. During the development of the project, laboratory and field tests will allow for the collection of experimental data to better define the durability evaluation and analyse advantages of the proposed approach in terms of life cycle assessment.