A major manufacturer of building supplies contracted Australasian Specialty Coatings to remediate several chemical storage bunds. All were partially degraded by chemical attack, but the sulphuric acid bund was in the worst state of all.
Pre-coating works included:
- Neutralising acid that had soaked into the concrete base and walls
- Pressure washing / water jetting away contaminated concrete
- Removing suspect areas of concrete by diamond grind, abrasive blast and jackhammer
- Rebuilding the bund shape to cover the damaged areas
- Filling all air pockets in the exposed concrete surface
- Cleaning and preparing steel tank legs for protective coatings
Sulphuric acid can be especially aggressive depending on the concentration, which would vary here depending on the size of any spill and the clean-up used.
A high-end novolac epoxy was specified to handle any spills or leaks of sulphuric acid, to be applied at a minimum thickness over 3 coats. It is critical to get sufficient thickness to protect the repair work and the underlying concrete.
The same coating was used for the steel, after first applying a zinc-rich epoxy primer.
The work was finished within budget and ahead of schedule, allowing the client to resume use of the bund sooner than expected. The novolac coating stood up to sulphuric acid spills within days of full curing and has continued to perform well.