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Fusion bonded epoxy coated steel

Fusion bonded epoxy coated steel is standard reinforcing steel covered with a thin coating of fusion bonded epoxy. At present there are no UK manufacturers and so any material must be imported. There is currently no British Standard for epoxy coated steel and hence it is important that the bar should conform to some other recognised standard, such as the appropriate ASTM standard.

It should be noted that cost of epoxy coated reinforcement is about twice the cost of uncoated steel. However, it may be a viable alternative in aggressive locations with the higher initial cost being justified by reduced maintenance or an extended service life. The normal requirements for concrete quality and cover should not be relaxed.

Epoxy coated steel has been used widely, particularly in North America, in bridges and marine structures. It has also been used to reduce or eliminate stray electrical currents, for example below light rail systems. No significant modifications to the usual design methods are required except that lap and bond lengths should be increased by about 25%.

Bars are generally supplied cut and bent, with the cut ends protected with epoxy paint. Care should be taken in handling and fixing the bars as any significant damage to the coating will affect the durability performance; any areas of damage should be painted with epoxy prior to casting. Plastic coated tying wire should be used. Bars can not be welded without destroying the coating. Hence for welded assemblies the cage should be fabricated from black bar and then the whole dipped in epoxy.

Acknowledgement: The Concrete Society