Numerical investigation on chloride-induced macro-cell corrosion of steel fiber reinforced concrete

Abstract

Steel corrosion is a significant deterioration issue of reinforced concrete structures in marine environments. Steel Fiber Reinforced Concrete (SFRC) is widely accepted to have better corrosion resistance than reinforced concrete (RC). Moreover, fibers in the cover inhibit corrosion of the reinforcement inside. However, the mechanism for SFRC corrosion has not been clarified yet, and the effective period of corrosion inhibition cannot be predicted. This paper proposes a space-averaged modeling method (including discrete and smeared models) for the macro-cell corrosion of SFRC. The method accurately reproduces the corrosion processes and rust distribution observed in previous pseudo-concrete experiments. Due to the chloride ion concentration difference, steel fibers dispersed in concrete solutions form a global macro-cell circuit. Thus, the corrosion of internal reinforcement is inhibited due to the cathodic protection. Additionally, using real chloride supplies in marine environments and concrete pore structures, fibers provides a more substantial corrosion inhibition duration ( > 10 years). This method can be used as a reliable reference for evaluating the corrosion of SFRC structures.