Effect of Addition of Chromate to Concrete on the Bond Strength of Hot-Dip Galvanized Ribbed Rebar at Ambient Temperature

Abstract:

This article studies the effect of chromate (CrO₄^2-) addition to concrete mix on the corrosion behavior of hot-dip galvanized reinforcement and primarily on the bond strength of this reinforcement with concrete. According to the original literature, the addition of chromates should prevent corrosion of the coating in fresh concrete with the evolution of hydrogen. The results show that this is indeed the case, but the need for a greater amount of added chromates also reduces the mechanical properties of the concrete. This ultimately affects the bond strength of the hot-dip galvanized reinforcement with concrete. Due to legislation, it is totally unacceptable to add any amount of chromates to the concrete mix (Cr^VI - toxic substance).

• Periodical: Key Engineering Materials (Volume 868)
• Pages: 10-14
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.868.10
• Online since: October 2020
• Authors: Petr Pokorný*, David Citek
• Keywords: Bond Strength, Chromate Addition, Corrosion of Steel in Concrete, Hot-Dip Galvanized Reinforcement

References

[1] NOVAK, P., MALA, R., JOSKA, L., Influence of pre-rusting on steel corrosion in concrete. Cement and Concrete Research, Volume 31, Issue 4, Pages 589-893, ISSN: 0008-8846, (2001).

DOI: 10.1016/s0008-8846(01)00459-8

[2] KOURIL, M., NOVAK, P., BOJKO, M., Limitations of the linear polarization method to determine stainless steel corrosion rate in concrete environment. Cement and Concrete Composites, Volume 28, Issue 3, Pages 220-225, ISSN: 0958-9465, (2006).

DOI: 10.1016/j.cemconcomp.2006.01.007

[3] CUSENS, A., YU, Z., Pullout tests of epoxy-coated reinforcement in concrete. Cement and Concrete Composites, Volume 14, Issue 4, Pages 269-276, ISSN: 0958-9465, (1992).

DOI: 10.1016/0958-9465(92)90025-q

[4] POKORNY P., TEJ, P., KOURIL, M., Evaluation of the impact of corrosion of hot-dip galvanized reinforcement on bond strength with concrete – A review. Construction and Building Materials, Volume 132, Pages 271-289, ISSN: 0950-0618, (2017).

DOI: 10.1016/j.conbuildmat.2016.11.096

[5] GALLEGO, A., et al., Comparison between concrete-black steel and concrete galvanized steel bond via the pull-out test supplied with acoustic emission. Conference EWGAE (poster 3), Pages 761-767, (2004).

[6] POKORNY, P., PERNICOVA, R., TEJ P., KOLISKO, J., Changes of bond strength properties of hot-dip galvanized plain bars with cement paste after 1 year of curing. Construction and Building Materials, Volume 226, Pages 920-931, ISSN: 0950-0618, (2019).

DOI: 10.1016/j.conbuildmat.2019.07.147

[7] BIRD, C. E., The influence of minor constituents in Portland cement on the behaviour of galvanized steel in concrete. Corrosion Prevention & Control, Pages 17-21, (1964).

[8] MANG, R., MULLER, R. H., Untersuchungen zur Anwendbarkeit feuerverzinkter Bevehrung im Stahlbeton-bau. Stahl und Eisen, Pages 889-894, (1982).

[9] CORDEROY, D. J. H., HERZOG, H., Passivation of galvanized reinforcement by inhibitor anions. Corrosion of reinforcing steel in concrete, ASTM, Pages 142-159, (1978).

DOI: 10.1520/stp27474s

[10] FAYALA, I., DHOUIBI, L., NÓVOA, X. R., OUEZDOU, M. BEN, Effect of inhibitors on the corrosion of galvanized steel and on mortar properties. Cement and Concrete Composites, Volume 35, Issue 1, Pages 181-189, ISSN: 0958-9465, (2013).

DOI: 10.1016/j.cemconcomp.2012.08.014