Austenitic and Lean Duplex Stainless Steel Rebars in Concrete Under Simultaneous Load and Marine Corrosion Effect: A Service Lifetime Study

The durability of reinforced concrete (RC) structures decreases as external aggressive agents penetrate through the concrete barrier and diffuse towards reinforcements, leading to the corrosion of reinforcements and reduction of the bearing capacity of the structure. This is not only a common issue for offshore and onshore infrastructures exposed to high chloride concentrations, waves, tidal actions and erosion processes; it is also critical for roads and bridges that are affected by environmentally assisted corrosion due to the use of de-icing salts. Thus, there are different solutions to deal with this problem. The In marine environments, the use of stainless steel (SS) reinforcements has shown great performance against corrosion. Nevertheless, there is lack of knowledge on the simultaneous and synergistic effects of load and corrosion performance of SS RC and how this combined effect influence RC service life-time. The study analyses the behavior of stress corrosion effect of SS RC beams by simulating service conditions on scaled specimen. The aim of this work is to evaluate the performance and outcome in terms of service life-time years when using different SS for RC beams with high chloride content within concrete matrix under the simultaneous effects of applied load and corrosion after long-term exposure. AISI 304 austenitic stainless steel, 2304 LDSS and 2001 LDSS lean duplex stainless steels rebars were tested and compared with B500SD carbon steel. The results show less diameter reduction of 2001 LDSS reinforcements offers minor diameter reduction, which postulate it as the most cost effective solution.