Durability of RC structures made with chloride-contaminated raw materials

Synopsis: Within the SeaCon project "Sustainable concrete using seawater, salt-contaminated aggregates, and non-corrosive reinforcement", financed by the Infravation program, an experimental study is being carried out, aimed at demonstrating the safe utilization of chloride-contaminated raw materials for the production of a sustainable concrete, when combined with non-corrosive reinforcement to construct durable and economical concrete infrastructures. Experimental tests are ongoing to assess the corrosion behavior of austenitic (S30403 and S24100) and duplex stainless steels (S31803 and S32304) reinforcing bars, and for comparison of carbon steel, embedded in concretes made with chloride-contaminated raw materials and subjected to different environmental conditions. This paper focuses on the results of tests carried out on reinforced concrete specimens exposed to ponding with a 3.5% NaCl solution for approximately one year, in order to simulate the effect of the further penetration of chlorides. Results showed that this condition led, in few days, to the initiation of corrosion on the carbon steel bars embedded in concretes made with chloride-contaminated raw materials. Neither the initial contamination nor the further penetration of chlorides led to the onset of corrosion on any of the stainless steel bars embedded in concrete made with chloride-contaminated materials.