Location

University of Leeds

Keywords

reinforcement corrosion, chloride ion diffusion, open-circuit potential, linear polarization

Abstract

This study explored the diffusion of the chloride ions influenced by the reinforcement corrosion in the mortar. It is believed that, during the corroding process, a small current is generated at the surface of the reinforcement. Such current is supposed to influence the diffusion of the chloride ions, but the relationship between both was not well studied in the literature. In this study, the corroded reinforcements were prepared by applied currents. Reinforced mortar specimens with w/c of 0.6 were then prepared and cured by either salt or fresh water. Results showed that the chloride ion distribution was likely associated with the reinforcement corrosion. During the early hydration, the chloride ions were attracted by the reinforcement corrosion in the specimens prepared with fresh water and cured in salt water. The concentration of the chloride ions near the surface of the reinforcement was increased with the increases of the charging time during the preparation for the corroded reinforcement. On the contrary, the chloride ions were likely bound in those specimens prepared with salt water and cured by saturated lime water. The concentration of the chloride ions near the surface of the reinforcement was higher than those near the outer surface. However, such influencing effects were not clear in the long term, possibly due to the hydration. The results of this study show that the reinforcement corrosion have influences on the diffusion of the chloride ions and such effect should be considered during the refinement of the traditional chloride ion diffusion models.

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Interactions Between Reinforcement Corrosion and Chloride Ion Diffusion in Mortar

University of Leeds

This study explored the diffusion of the chloride ions influenced by the reinforcement corrosion in the mortar. It is believed that, during the corroding process, a small current is generated at the surface of the reinforcement. Such current is supposed to influence the diffusion of the chloride ions, but the relationship between both was not well studied in the literature. In this study, the corroded reinforcements were prepared by applied currents. Reinforced mortar specimens with w/c of 0.6 were then prepared and cured by either salt or fresh water. Results showed that the chloride ion distribution was likely associated with the reinforcement corrosion. During the early hydration, the chloride ions were attracted by the reinforcement corrosion in the specimens prepared with fresh water and cured in salt water. The concentration of the chloride ions near the surface of the reinforcement was increased with the increases of the charging time during the preparation for the corroded reinforcement. On the contrary, the chloride ions were likely bound in those specimens prepared with salt water and cured by saturated lime water. The concentration of the chloride ions near the surface of the reinforcement was higher than those near the outer surface. However, such influencing effects were not clear in the long term, possibly due to the hydration. The results of this study show that the reinforcement corrosion have influences on the diffusion of the chloride ions and such effect should be considered during the refinement of the traditional chloride ion diffusion models.