The inhibiting behavior of many organic and inorganic substances against steel corrosion was evaluated in an alkaline chloride solution, constituted by a saturated calcium hydroxide solution containing 0.1 M chloride ions. Besides 0.05 M sodium nitrite (SN), among the tested substances, only 0.005 M 5-hexyl-benzotriazole (C6BTA), 0.05 M sodium β-glycerophosphate (GPH), and saturated dicyclohexylammonium nitrite (DCHAMN) were able to prevent pitting corrosion over 30-day exposures to the aggressive electrolyte. Moreover, very good results were obtained with steel specimens coated by DINITROL AV 30®, which is a commercial corrosion inhibitive filming product. Chloride-polluted mortars embedding steel rods were also prepared to assess the influence of the most promising inhibitors, added either as admixtures or as impregnation agents, under conditions closer to those experienced in concrete. The inhibiting efficiencies (IE) were tested by Electrochemical Impedance Spectroscopy (EIS). Good results were obtained with admixed tungstosilicic acid (TSAH), with GPH or DCHAMN penetrated from the outside or in the presence of DINITROL AV 30® coating.
Study on corrosion inhibitors for concrete application
MONTICELLI, Cecilia;FRIGNANI, Alessandro;TRABANELLI, Giordano
2000
Abstract
The inhibiting behavior of many organic and inorganic substances against steel corrosion was evaluated in an alkaline chloride solution, constituted by a saturated calcium hydroxide solution containing 0.1 M chloride ions. Besides 0.05 M sodium nitrite (SN), among the tested substances, only 0.005 M 5-hexyl-benzotriazole (C6BTA), 0.05 M sodium β-glycerophosphate (GPH), and saturated dicyclohexylammonium nitrite (DCHAMN) were able to prevent pitting corrosion over 30-day exposures to the aggressive electrolyte. Moreover, very good results were obtained with steel specimens coated by DINITROL AV 30®, which is a commercial corrosion inhibitive filming product. Chloride-polluted mortars embedding steel rods were also prepared to assess the influence of the most promising inhibitors, added either as admixtures or as impregnation agents, under conditions closer to those experienced in concrete. The inhibiting efficiencies (IE) were tested by Electrochemical Impedance Spectroscopy (EIS). Good results were obtained with admixed tungstosilicic acid (TSAH), with GPH or DCHAMN penetrated from the outside or in the presence of DINITROL AV 30® coating.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
