Effect of Calcium Nitrite and Nano TiO2 Admixed Cement Slurry Coatings on Corrosion of Steel

The corrosion control mechanisms of ordinary Portland cement (OPC) slurry-coated, calcium nitrite admixed OPC slurry-coated and nano-TiO2 admixed OPC slurry-coated steel under normal water and saline water (3.5% NaCl) exposure were investigated. To estimate the corrosion rate of coating systems, the potentiodynamic polarization measurements were performed after 30, 60, 90, and 120 days of exposure in normal and saline environments. The weight loss measurements at the exposure duration of 120 days were also carried out to validate the results of potentiodynamic polarization measurements. Moreover, setting time and compressive strength were also determined to assess the impact of calcium nitrite and nano-TiO2 on the quality of cementitious composite. The results revealed that all the coating systems showed a significant degree of corrosion inhibition as compared to bare steel. The calcium nitrite and nano-TiO2 admixed cement slurry-coated steel showed higher corrosion inhibition efficiency than OPC slurry-coated steel.