Protect of reinforcement steel in repaired structures is important. There are various ways and means of protecting steel and mitigating corrosion in future. One of the simplest methods is application of thick cement slurry on steel bars just prior to placing of replacement material over it. This method is economical but the slurry film only containing cement may develop cracks. The quality of concrete placed on the repaired structure also has to be dense and should be able to bond mechanically and chemically with steel and old concrete surface

             Application of liquid epoxy o bars is frequently done. Epoxy application is a two parts system. Hence, stiffener and hardener have to be mixed properly using mechanical stirrers and the replacement concrete has to be placed over the epoxy coated steel before the epoxy hardens. These are often neglected and result in reduction of bond between steel and concrete around it. The epoxy coating is a very good barrier film but does not contribute in anyway in creating non-corrodible (alkaline) conditions around the steel.

           A slurry of water based polymer emulsion and cement prepared using mechanical stirrers is a better option as it helps in maintaining alkaline environment and it also forms a strong barrier film around the steel. Being a cement based coating, it provides alkalinity at the same time providing a tough as well as flexible film over the steel.