Inhibition effect of lactate on localized corrosion of steel in chloride contaminated concrete

The paper summarizes the results of testing performed in order to study the inhibition properties of salts of the lactic acid for prevention of rebar corrosion in chloride contaminated concrete. Electrochemical and weight loss tests were carried out in concrete and calcium hydroxide solutions in order to analyze the effect on pitting initiation and propagation of chloride and lactate concentrations. Lactate anions can reduce pitting initiation in alkaline solutions. The inhibition efficiency increases as the lactate/chloride molar ratio increases. Furthermore, the lactate anions may be able to slow pit growth, but only for lactate /chloride ratio higher than one. The tests in concretes were carried out at unit lactate/chloride ratio. In presence of lactate ions the localised attack of the rebar always was very low and limited to crevice areas.