Caratterizzazione di miscele binarie per l’inibizione della corrosione dell’acciaio al carbonio in soluzione alcalina

Corrosion inhibitors are used to prevent or delay corrosion of steel reinforcements in concrete. This paper presents the results of potentiostatic polarization tests carried out in alkaline solution (simulating concrete pore solution), in the presence of chlorides up to 0,8 mol/L. Tests were carried out on binary mixtures made with organic substances (amines, aminoacids and carboxylates) and nitrite, selected in a previous research phase. Total concentration of inhibiting admixture was 0.1 mol/L, with different concentration ratios. Most of the mixtures exhibited an improvement in localized corrosion resistance, but their inhibiting performance was worse than the performance of nitrite alone. Synergistic behavior, evident for some mixtures in potentiodynamic polarization tests, was not confirmed in potentiostatic polarisation.