Mechanism of inhibitors in control of corrosion of steel in concrete

Reinforced concrete is the most abundantly used material in the infrastructure industry. Corrosion of reinforcing steel is the most critical and significant problem that the building industry faces. This durability issue is primarily caused due to chloride attack or carbonation of concrete. Among other techniques used in producing high-performance concrete, the use of corrosion inhibitors is the most attractive from the view of cost and ease of application. There is a diverse range of available corrosion inhibitors that are classified based on their origin, mechanism of protection, and composition. This paper covers a critical overview of the different mechanisms of corrosion protection offered by corrosion inhibitors. Furthermore, the stricter enforcement of environmental rules has prompted and inspired researchers to focus on developing non-toxic and ecologically acceptable corrosion inhibitors. This paper also gives a brief account of the ecological sustainability and toxicity issues concerning the commercially available inhibitors and the versatility and effectiveness of green corrosion inhibitors compared to synthetic corrosion inhibitors. This account of corrosion inhibitors attempts to contribute towards developing awareness and understanding of the primary mechanism of protection and the use of innovative and green materials to increase the service life of steel-reinforced concrete.