Concrete Corrosion: Causes and Restoration
Corrosion occurs when the steel reinforcements embedded in concrete deteriorate due to chemical or electrochemical reaction within its environment. When steel is embedded in concrete, a passive oxide film forms on its surface. While the passive film is present the steel is immune to corrosion and can perform its job, which is to give stability to the structure. If the concrete becomes carbonated then the pH of the concrete can fall thereby causing the loss of passivity and the onset of corrosion.