Corrosion behavior of steel in simulated concrete pore solutions treated with calcium silicate hydrates

Corrosion behavior of steel in simulated concrete pore solutions treated with calcium silicate hydrate (C–S–H) was studied with the methods of ion selective electrode analysis, potentiodynamic polarization and impedance measurement. The results indicate that C–S–H could effectively adsorb chloride ions and decrease chloride content in simulated concrete pore solution. But the effects of C–S–H addition on pore solutions of different pH values are different. For pore solutions with pH 12.5 and 11.9, the pH values decrease after C–S–H treatment, and pitting potential Epit and polarization resistance Rp of the steel decline. While for pore solutions with pH 10, 9.7 and 9.3, after C–S–H treatment the pH values increase, and both the Epit and Rp of the steel arise. The related mechanisms are preliminarily discussed.

► Corrosion behavior of steel in concrete pore solutions treated with C–S–H is studied.
► C–S–H could effectively decrease chloride content in pore solutions.
► Effects of C–S–H are different for pore solutions of different pH values.
► After C–S–H treatment, corrosion resistance of steel decreases in solutions (pH > 10).
► After C–S–H treatment, corrosion resistance of steel increases in solutions (pH < 10).