Exploring Damage Projections for Corroding Stainless and Carbon Steel Reinforced Concrete

Abstract The durability of reinforced concrete structures is significantly impacted by steel reinforcement corrosion, especially in aggressive environments. To address this, corrosion-resistant alloys like stainless steel (SS) have gained attention. Studies have indicated that despite higher material costs, the longer service life of SS reinforcement may justify the cost, as its chloride threshold can be up to ten times greater than that of carbon steel (CS) reinforcement. However, there are currently no models available to accurately forecast the corrosion of SS-reinforced infrastructure, and durability projections for CS do not consider mechanistic differences. Previous work has shown that chloride-induced corrosion of SS leads to localized pit clusters, affecting evaluation of the serviceability limit state. This work presents damage projections for corroding SS using the Potential-Dependent Threshold (PDT) model with an ionic migration effect on an exploratory 2D model. The results project that SS benefits significantly from the combined effects of cathodic prevention and hydroxide ion accumulation, both of which contribute to a notable increase in an already high chloride threshold. This leads to a slower rate of lateral spread of corrosion damage compared to CS. It is anticipated that projections of this form will help inform the appropriate serviceability limit state that controls the duration of the corrosion propagation stage.