Improving the durability of prestressed concrete structures by employing high strength duplex stainless steels

The corrosion behaviour of 2304 duplex high strength stainless steel has been analysed in the present work by determining the chloride threshold (CT) for corrosion initiation in mortar by means of accelerated tests. Effect of cold drawing has been studied by comparing parent low strength wires with cold-drawn high strength wires. Potentiostatic polarization tests in chloride-free and chloride mixed-in mortars have been carried out. The CT determined by using chloride penetration tests in chloride-free mortar varied from 3.06±0.5% total Cl¯ (with respect to cement weight) for cold drawn SS to 2.3% total Cl¯ for parent SS. On the other hand, the CT values determined by means of potentiostatic tests in chloride mixed-in mortar was 1.8±0.2 % Cl¯ for parent and 2.1±0.5% Cl¯ for cold drawn SS