A Review of Oxide Layer Formation and Corrosion Dynamics in Reinforced Concrete

Abstract

Corrosion is a natural phenomenon that threatens the durability of steel reinforcement in reinforced concrete. Initially, the reinforcement is protected by a layer of iron oxides known as the passivation layer, formed due to the high alkalinity of the concrete medium. This passivation layer acts as a barrier, preventing the progression of corrosion by isolating the steel from corrosive elements. However, the incorporation of corrosion catalysts such as chlorides or carbon dioxide can destroy this protective layer. Once the passivation layer is compromised, reinforcement corrosion begins, leading to the formation of more complex iron oxides, such as rust (Fe2O3). These corrosion products influence the characteristics of the environment around the reinforcement, creating cracks in the concrete and facilitating the penetration of water and other corrosive agents. This process promotes the spread of corrosion within the reinforced concrete structure, accelerating its deterioration. An extensive analysis of the development of the oxide layer on steel reinforcement is given in this article, and its impact on the interface between reinforcement and concrete. It explores the mechanisms by which the passivation layer is formed and the conditions that lead to its failure.