The durability of zinc galvanised steel has been highlighted in research from South Africa that was published in the journal Civil Engineering earlier in 2018.
Back in the summer, the publication reported on the findings of tests carried out on the Diepkloof Bridge, a zinc galvanised steel bridge built in 1980 with a planned service life of at least 100 years.
The designers achieved this by galvanising steel reinforcing strips on the bridge with 750 microns of sacrificial thickness of zinc, allowing for wear and tear over the course of the century without the steel beneath being affected.
After 11 years the thickness of the zinc was tested and, in 2017, the remaining zinc layer was measured again to reveal how much of the sacrificial thickness has been lost during the first third or more of the bridge’s designed life span.
The research found just 15 microns of zinc has been lost from either side of the galvanised steel reinforcing strips – leaving 735 microns, or 98% of the original galvanising layer intact.
Researchers added that as yet, there is no sign of any corrosion to the steel itself, an indication that the zinc galvanising layer is working as intended.
Diepkloof Bridge is just one example of how effective zinc galvanising steel can be in terms of protecting it for the short term and preserving it for the long term, as the zinc coating is gradually sacrificed to prevent damage to the steel underneath.
This sacrificial corrosion process allows galvanised steel to be worked and fabricated too – for example, galvanised steel can be cut or drilled, and still remain fully protected.
At James Dunkerley Steels we offer galvanising of the steel we manufacture as part of our light fabrication services, so whether you need galvanised steel sections for fabrication later, or you want us to carry out fabrication of steel cabinets and other units with a galvanised finish, we can cater for your needs.
We galvanise steel using a hot zinc bath, whereby the metal is dipped into molten zinc to metallurgically bond the galvanising layer to the surface of the steel – giving a smooth, consistent and reliably durable finish.