How Much Corrosion in Rebar is Too Much?

Severe corrosion in rebar can cause too much pressure on surrounding concrete, leading to cracking and ultimate structural failure.

Corrosion in Rebar

It's for this reason that, despite its added expense, epoxy coated rebar is used for construction projects that will be exposed to salt water, such as highways, bridges, coastal areas and parking garages to name just a few.

But can corrosion in rebar actually be a good thing? In many construction applications, some amount of rust can indeed improve the bond of rebar to its concrete surroundings, as it increases the area and friction of the steel surface. That's good.

So at what point is does rust become harmful to the structural integrity of concrete? If there is so much corrosion that either the weight of the bar or the height of the deformations is reduced, this can lead to faulty concrete and visible rusting and cracking. That's bad.

Corrosion in rebar can be prevented through by applying an epoxy coating, by running a small amount of electrical current through the steel or by choosing cement with a higher pH level and greater sulphate resistance.

In short, there's a lot to consider before picking up that rusty rebar that's been sitting on the job site for weeks. Proceed with caution and consult a professional, like the full service fabrication experts at White Cap.

 

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