It has been established by researchers here and overseas that the galvanizing of reinforcement can greatly improve its resistance to corrosion in concrete.

It is not realistic to make generalised quantitative assessments of expected increases in the lives of structures, which would result from galvanizing, because there are too many factors involved. However, there are numerous case histories documented in the literature, which provide interesting and reliable information.

Because of the complexities involved, the question whether or not to use galvanized reinforcement in a particular structure has no simple or general answer. The breakdown of concrete as an effective barrier against corrosion of reinforcement is generally due to a combination of unfavourable factors.

There are certain situations in which the long-term durability of the structure is clearly likely to be questioned and where galvanized reinforcement should therefore receive special consideration.

This is particularly so in aggressive exposure situations and high-risk structures, and in prestige construction where a long maintenance-free service life is required.

References

1. AS 3600 – 2001 Concrete structures
2. AS/NZS 4680 – 1999 Hot-dipped galvanized coatings on fabricated ferrous articles
3. Galvanizers Association of Australia Standard Specification for Hot-Dip Galvanized Coatings
4. Yeomans SR. ‘Performance of Black, Galvanized and Epoxy Coated Reinforced Concrete’ Corrosion. 50(1), 1994, pp 72-81
5. Yeomans SR. ‘Corrosion of the Zinc Alloy Coating in Galvanized Reinforced Concrete’ Corrosion/98 Paper No. 653, NACE, Houston, Texas 1998
6. AS/NZS 4671 – 2001 Steel reinforcing materials
7. Yeomans SR and Ellis DR. ‘Further Studies of the Bond Strengths and Slop Characteristics of Galvanized and Epoxy Coated Steel Reinforcement in Concrete’. ILZRO Project ZE-341. University of New south Wales. Canberra ACT. Progress Report No 5., December 1992