Carbonation induced corrosion in concrete: Evaluation of a nitrate based corrosion inhibitor

Rebars corrosion is one of the most important phenomena affecting durability of reinforced concrete structures. Corrosion inhibitors are considered as an effective preventative technique to slow down the onset and/or propagation of corrosion. Several substances have been evaluated as possible candidates, among these the most used commercial inhibitor is based on nitrites. Recently, nitrate based compounds have been proposed as corrosion inhibitors, as they present lower cost than nitrites and are already used in concrete as set accelerators. Some studies have shown that nitrates inhibiting mechanism is similar to that of nitrites. This work evaluate a nitrate based substance as possible corrosion inhibitor in carbonated reinforced concrete. The results show that the nitrate is able to delay concrete carbonation but has no effect on corrosion rate after the corrosion initiation.