The use of inorganic conversion coatings to enhance the corrosion resistance of reinforcement and the bond strength at the rebar/concrete

The performance of concrete specimens reinforced with uncoated rebars or rebars coated with inorganic conversion coatings was investigated. The corrosion resistance of rebars and the bond strength at the rebar/concrete interface for uncoated rebars as well as rebars coated with three different inorganic conversion coatings were evaluated according to the corresponding ASTM G109 standard. The results showed that different inorganic conversion coatings give significant enhancements of corrosion resistance and increased interface bond strength compared to uncoated ordinary steel rebars. However the extent to which each conversion coating improves the corrosion resistance of the rebars and the interface bond strength inevitably depends on the chemical composition of the applied inorganic conversion coating.