Effect of Calcium Nitrate and Sodium Nitrite on the Rebar Corrosion of Medium Carbon Steel in Seawater and Cassava Fluid


Inhibitors are regularly used as one of the principal prevention and control techniques in reinforcement corrosion. Hence this study investigates the effect of calcium nitrate and sodium nitrite inhibitors on the rebar corrosion of medium carbon steel in seawater and cassava fluid with a view to determining inhibitive potentials of the different inhibitors in the two media. Gravimetric and voltametric techniques were employed in this study and a total of forty-five corrosion coupons of different dimensions were produced. Forty coupons were used for gravimetric analysis and the remaining five for corrosion potentials measurements. Eight of the samples were used as control; while other eight samples each were admixed with calcium nitrate and sodium nitrite in concrete cubes. It was later immersed in seawater and cassava fluid for a total duration of 32 days and the measurements were taken at the interval of 4 days in order to determine the corrosion rates in mils per year (mmpy). Two controls and admixed samples each were later immersed in seawater and cassava fluid, respectively, for durations of 32 days to determine the corrosion potentials using a voltmeter and a Copper-Copper Sulphate Electrode (Cu/CuSO4). The pH of each medium was measured throughout the period of exposure. The results obtained expressed that all the samples except the control samples, displayed some degree of inhibition. The inhibition levels for the admixed samples in seawater were higher compared with those in cassava fluid. Inhibition efficiencies for various inhibitors followed different trends in different environment. The inhibition efficiencies for calcium nitrate in cassava fluid and seawater were 26.81% and 64.85% respectively. The study concluded that inorganic inhibitors were effective in inhibiting corrosion in cyanide and chloride contaminated concrete cubes.

Share and Cite:

Adamu, M. , Umoru, L. and Ige, O. (2014) Effect of Calcium Nitrate and Sodium Nitrite on the Rebar Corrosion of Medium Carbon Steel in Seawater and Cassava Fluid. Journal of Minerals and Materials Characterization and Engineering, 2, 223-229. doi: 10.4236/jmmce.2014.23027.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Charles, I.S. (1997) Improved Corrosion Inhibiting Pigments. Arabian Journal for Science and Engineering, 27, 40-42.
[2] Ailor, W.H. (1964) Handbook on Corrosion Testing and Evaluation. Wiley, Etobicoke, 1150-1165.
[3] Hackerrman, N. (1965) Fundamentals of Inhibitors. NACE Basic Corrosion Course, NACE, Houston.
[4] Al-Amoudi, O.S.B. and Maslehuddin, M. (1993) The Effect of Chloride and Sulphate Ions on Reinforcement Corrosion. Cement and Concrete Research, 23, 139-146.
[5] Popovics, S. (1998) Strength and Related Properties of Concrete: A Quantitative Approach. John Wiley & Sons, Inc., New York, 122.
[6] Maslehuddin, M. and Al-Amoudi, O.S.B. (1992) Corrosion of Reinforcing Steel in Concrete: Its Monitoring and Preventions. Symposium on Corrosion and Its Control. Pre-Print, King Saud University, Riyadh, 80-90.
[7] Fontana, M.G. and Greene, N.D. (1996) Corrosion Engineering. McGraw-Hill Book Co., New York, 28-116.
[8] Akindahunsi, A.A., Oboh, G. and Oshodi, A.A. (1999) Effect of Fermenting Cassava with Rhizopus Oryzae on the Chemical Composition of Its Flour and Garri. Rivista Italiana delle Sostanze Grasse, 7, 437-440.
[9] Olorunniwo, O.E., Umoru, L.E. and Bamigboye, O.R. (2008) Sodium Chromate and Diethylene Amine as Corrosion Inhibitors for Mild Steel in Cassava Fluid. Journal of Applied Science, 4, 878-882.
[10] West, R.E. and Hime, W.G. (1975) Chloride Profiles in Salty Concrete. Materials Performance, 5, 29-36.
[11] James, A.O. and Akaranta, O. (2009) The Inhibition of Corrosion of Zinc in 2.0 M Hydrochloric Acid Solution with Acetone Extract of Red Onion Skin. African Journal of Pure and Applied Chemistry, 3, 212-217.
[12] Hackerman, N. and Snavely, E.S. (1984) Corrosion Basics: An Introduction. NACE, Houston, 127-146.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.