Improving concrete durability through the use of corrosion inhibitors

Author(s): I.N. Robertson
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 197 – 198
Total Pages: 2
Language: English

Abstract: 
Corrosion of reinforcing steel is a major contributor to early deterioration of concrete structures in a coastal environment. This paper presents the results of a ten year laboratory accelerated corrosion study and an eight year field study involving 25 reinforced concrete panels exposed to a marine tidal zone. Seven different corrosion inhibiting admixtures and two pozzolans were used in the laboratory and field studies to compare their effectiveness at preventing or delaying onset of corrosion. This study was funded by the Hawaii Dept. of Transportation, Harbors Division, in order to evaluate commercially available corrosion inhibiting admixtures when used in concretes made with basalt aggregates common to Hawaii and other Pacific Islands.
The corrosion-inhibiting admixtures included in this project were Darex Corrosion Inhibitor (DCI), Rheocrete CNI, Rheocrete 222+, FerroGard 901, Xypex Admix C-2000, Latex-modifier, Kryton KIM, and the pozzolans were fly ash, and silica fume.
Based on an assessment of the performance of field panels and the corresponding laboratory specimens with the same concrete mixtures, it was found that DCI, CNI, fly ash and silica fume all provided improved corrosion protection compared with the control specimens. Kryton KIM performed well in a field panel, but was not included in the laboratory study. As expected, the control mixtures with lower water cement ratio (0.35) performed better than control mixtures with higher water-cement ratio (0.40).
Concrete mixtures using Rheocrete 222+, FerroGard 901, Xypex Admix C 2000 or Latex-modifier showed mixed results. Some mixtures exhibited improved performance compared with the control mixtures, while others did not. Based on the results of this study, these corrosion inhibiting admixtures cannot be recommended for concrete using Hawaiian aggregates in a marine environment.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00