The corrosion inhibition efficiency of aluminum tripolyphosphate on carbon steel in carbonated concrete pore solution

The efficiency of aluminum tripolyphosphate (ATP) as inhibiting agents for carbon steel was studied in a carbonated concrete pore solution and mortars, respectively. The polarization resistance of the steel and the resistance of the concrete cover layer significantly increased when the content of ATP in mortars increasing. The electrochemical and surface analysis suggests that the stability of the passive film on carbon steel was enhanced by ATP; a tripolyphosphate adsorbed layer also formed on the surface of the steel. Consequently, the pitting corrosion of the steel was effective hindered by ATP both in the pore solution and mortars.