Effect of Red Mud on the Corrosion of Reinforced Concrete Studied by Electrochemical Impedance Spectroscopy

The corrosion of concrete reinforcement is a global issue that poses serious hazards, including potential fatalities related to material degradation. The objective of this study was to evaluate the effect of adding red mud, a byproduct of bauxite processing, on the corrosion behavior of steel bars embedded in concrete. We employed electrochemical impedance spectroscopy (EIS) to assess the corrosion rates and onset within concrete specimens containing varying proportions of red mud, up to 30% of the total binder, under conditions of partial immersion in a sodium chloride solution. Our findings revealed that the incorporation of red mud significantly delayed the onset of corrosion and may also have contributed to a reduction in the corrosion rate of the steel reinforcement. These results underscore the potential of using red mud as a supplementary material in concrete to enhance its durability against corrosion, thereby improving the longevity and safety of reinforced concrete structures.