Phosphate coatings for the protection of steels reinforcement for concrete

Concrete and reinforced concrete are the most popular and safest building materials today. The concrete and its steel reinforcements work together to withstand to complex operating stresses. Accordingly, while the steel reinforcement resists very well to tensile forces, the concrete structure will successfully resist to significant compression efforts. According to the concrete manufacturers, under optimal conditions, the durability of this composite material is almost infinite. However, when poor quality concrete, with structural defects, is subjected to certain environmental conditions (rain, ice or air chemicals), its integrity can be severely affected, consequently, its mechanical properties will decrease. Usually, the concrete protects the steel used as reinforcement, but there are specific situations in which its protective and anticorrosive properties are very limited. Thus, the properties of reinforced concrete decrease, endangering the structure of the concrete buildings. This article aims to provide a compressive review regarding the methods used to protect the reinforcement steel against corrosion. Moreover, one of the most widely used methods will be emphasized, namely phosphating, which in addition to improving the corrosion resistance properties, it also supports the adhesion between steel and concrete.