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Advances in Materials Science and Engineering
Volume 2015 (2015), Article ID 540395, 11 pages
http://dx.doi.org/10.1155/2015/540395
Research Article

Effect of NaNO2 and C6H15NO3 Synergistic Admixtures on Steel-Rebar Corrosion in Concrete Immersed in Aggressive Environments

1Mechanical Engineering Department, Covenant University, Ota 112001, Nigeria
2Chemical and Metallurgical Engineering Department, Tshwane University of Technology, Pretoria 0001, South Africa

Received 5 October 2014; Accepted 2 March 2015

Academic Editor: Richard Hennig

Copyright © 2015 Joshua Olusegun Okeniyi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper studies effect of different combinations of NaNO2 (sodium nitrite) and C6H15NO3 (triethanolamine (TEA)), as synergistic admixtures in concrete immersed in NaCl and in H2SO4 test environments, on the corrosion of the concrete reinforcing steel (rebar). Although statistically analysed electrochemical test results confirmed NaNO2 effectiveness, synergistic combinations of 4 g NaNO2 + 4 g C6H15NO3 in NaCl medium and of 2 g NaNO2 + 6 g C6H15NO3 in H2SO4 medium were also highly effective at inhibiting rebar corrosion. Synergistic parameter analyses showed that the effective synergistic admixtures that inhibited concrete steel-rebar corrosion in their respective medium were the NaNO2 and C6H15NO3 combinations that exhibited synergistic interactions of cooperative adsorption on steel-rebar. These support the suitability of requisite concentration of triethanolamine as additive admixture with sodium nitrite for steel-rebar corrosion mitigation, which is potent with reduced environmental effects, in concrete immersed in NaCl and in H2SO4 corrosive media.