The corrosion behaviour of steel rods embedded in a chloride polluted mortar containing sodium glycerophosphate (GPH) -sodium nitrite (SN) admixtures was studied by EIS technique and polarization curve recording. As a reference, the severity of the corrosion attacks on steel rods exposed to either a chloride-polluted mortar inhibited or not by SN as well as to a chloride-free uninhibited mortar was also tested. The resistance of steel rods to pitting corrosion is excellent in the presence of SN alone. However, good corrosion resistance was also achieved in the presence of GPH + SN. The lower nitrite amount in the latter mortar can reduce the toxicity problems caused by this anion. GPH is known to protect passive conditions by chemisorptio on the oxide surface film. The synergism in the inhibition process achieved by the admixtures is due to the nitrite oxydizing properties, which allow the oxide film forming and repairing on defects.
A study on the inhibiting efficiency of a glycero-phosphate-nitrite admixtures against steel corrosion in mortars
MONTICELLI, Cecilia;FRIGNANI, Alessandro;TRABANELLI, Giordano;BRUNORO, Giancarlo
1995
Abstract
The corrosion behaviour of steel rods embedded in a chloride polluted mortar containing sodium glycerophosphate (GPH) -sodium nitrite (SN) admixtures was studied by EIS technique and polarization curve recording. As a reference, the severity of the corrosion attacks on steel rods exposed to either a chloride-polluted mortar inhibited or not by SN as well as to a chloride-free uninhibited mortar was also tested. The resistance of steel rods to pitting corrosion is excellent in the presence of SN alone. However, good corrosion resistance was also achieved in the presence of GPH + SN. The lower nitrite amount in the latter mortar can reduce the toxicity problems caused by this anion. GPH is known to protect passive conditions by chemisorptio on the oxide surface film. The synergism in the inhibition process achieved by the admixtures is due to the nitrite oxydizing properties, which allow the oxide film forming and repairing on defects.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
