Rebar Corrosion: How to Stop Concrete Cancer
Wholesale, mill-certified reinforcing steel — export-direct at mill prices.
Why reinforcement corrodes
Concrete normally passivates steel with its high alkalinity. Two things break that: carbonation (CO₂ lowering the pH over time) and chloride ingress (salt from seawater or de-icing). Once the passive layer fails, steel rusts, the rust expands up to six times, and the cover cracks and spalls — ‘concrete cancer’.
The prevention toolkit
In order of first defence: adequate cover and low-permeability concrete (the cheapest, most effective control), then coated or corrosion-resistant bar where exposure is severe — galvanized, epoxy-coated, stainless or GFRP. Design measures include crack-width control, drainage detailing and, for critical structures, cathodic protection.
Matching protection to exposure
Don’t over- or under-spec. Mild internal environments: bare B500B with proper cover. Coastal/marine or de-iced decks: galvanized or stainless. We supply B500B in bare and galvanized forms and can advise the exposure-class-appropriate solution rather than a blanket premium.
FAQ
What causes rebar to corrode inside concrete?
Chlorides (salt) and carbonation break down the concrete’s protective alkalinity, letting the steel rust and expand.
What is the cheapest way to prevent rebar corrosion?
Adequate cover and low-permeability, well-compacted concrete — before reaching for coated bar.
When is stainless or galvanized rebar worth it?
In marine, coastal or de-iced structures where chloride exposure is high and repair costs dwarf the material premium.
Need b500b rebar at export prices?
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