2. Type of Corrosion Protection
•As per NACE international, “a corrosion inhibitor is a substance when added to an environment,
either continuously or intermittently to prevent corrosion by forming a passive film on the
metal.”
•However, the performance of an inhibitor in concrete is a function of numerous inter-related
factors that is difficult to be predicted. Hence formation of the passive layer on the steel is not
guaranteed.
•Fusion Bonded Epoxy Coating is barrier layer coating which is directly applied to the steel bar
surface. Hence, corrosion inhibitors can be described as secondary protection which alone will
not ensure corrosion protection to steel bars.
3. Codal Provisions
Corrosion Inhibitor is not recommended
for corrosion protection for steel
reinforcement bars under Durability
Recommendations for Service Life of at
Least 100 Years
Does not recommend corrosion inhibitors for
corrosion protection for steel reinforcement bars
for severe environment.
IRC 112-2020
Code of practice for concrete road
bridges
IRC SP 80-2008
Corrosion Resistance
4. Performance
Performance of corrosion inhibitors is not documented much to provide conclusive evidence of
its effectiveness.
Based of studies and reports, manufacturers suggest different corrosion inhibitor dosage in
concrete based on environment factors. However, behavior of these inhibtors also change based
on the grade and quality of concrete. Hence it is very difficult to achieve same performance in
large valumes of concrete. Hence, corrosion inhibtors are suggested for use in repar works
where concrete volume is less.
If the corrosion inhibitor dosage is higer or lower than the needed dosage will result in non
formation of the passive layer, hence leading to inefficient protection of the steel rebars.
Some inhibitors get leached out over an extended period of exposure.
5. Applications
Corrosion Inhibitors can find application in repair works of small
volume as it is difficult to achieve perfect batches of concrete over a
large scale.
