Deicers, such as the salts used in snow melt products, can have an adverse effect on concrete surfaces, showing up as cracks or scaling. Scaling is the flaking or peeling of a finished concrete surface, and is typically a result of the presence of moisture and deicing salt on concrete during freezing and thawing.
According to the National Ready Mixed Concrete Association, most scaling is caused by:
- Excessive application of calcium or sodium chloride deicing salts, especially if concrete does not have adequate air entrainment or hasn’t been properly cured.
- Insufficient curing, which leads to a weak surface skin.
- The use of non-air-entrained concrete.
- Bleed water that’s been worked back into the surface, causing a high water-to-cement ratio.
So how can you prevent concrete scaling?
- DO practice proper curing practices; this ensures the proper reaction of cement with water, thereby creating a stronger surface.
- DO allow adequate air entrainment
- DO protect newly placed concrete from harsh winter weather and freezing temperatures with concrete sealers or concrete blankets.
- DON’T overwork the concrete surface during finishing. Overworking can reduce air content, leaving the concrete slab susceptible to scaling when temperatures drop below freezing.
- DON’T use deicing salts, such as calcium or sodium chloride, within the first year of freshly placed concrete. Instead, use sand to increase traction, and hose off surfaces to remove salt deposits left behind by cars.
- DON’T use ammonium sulfate or ammonium nitrate as deicers; these aggressive chemicals will destroy concrete surfaces.
Concrete placed during spring and summer will usually have enough drying time to survive freezing and thawing, whereas concrete placed during fall won’t have the same advantage. These tips go a long way toward protecting concrete surfaces against scaling from freezing and thawing. Questions? Stop into any of Intermountain Concrete Specialties’ six locations for expert advice on the best way to protect your concrete slabs from the potentially harsh effects of winter weather and deicers and prevent concrete cracks and scaling.