Chemical storage
I need to build a concrete bund wall to prevent spillage of chemicals. Should the concrete have a chemical protective coating?
Answer
Bunds are generally used around storage tanks or drum storage areas and should be sized to hold 110% of the maximum capacity of the largest tank or drum. They are an essential secondary containment for hazardous liquids, particularly where there are large quantities stored. Bunds are generally masonry or concrete. Such materials provide adequate chemical resistance to most liquids. However, where surfaces may be exposed to strong acids for long periods acid resistant coatings should be used.
Swimming pool chemicals instance include various kinds of disinfectants and sanitizers that work to control the growth of certain kinds of algae and bacteria in the pool water and can be aggressive to concrete.
A highly chemical resistant epoxy or polyurethane resin should be used particularly with acidic solutions (hydrochloric acid, sodium bisulphate, aluminium sulfate). However it is important to match the system with the chemical concentration. There is no point in placing a protective system if exposure is minimal or the concentration is not detrimental.
The PCA publication ´Effects of substances on concrete and guide to protective treatments´ can be downloaded from the PCA catalogue
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