When de-icing salts are applied to ice, they melt the ice and turn it back into water. The water is then absorbed into the concrete where it re-freezes inside the pores, causing the concrete to break apart. Concrete with freeze thaw damage often appears cracked, and has divots and chunks missing from the surface. While de-icing salts help to create a safer walking surface, they can cause freeze-thaw damage to the concrete.
The best way to prevent freeze-thaw damage to your concrete is to reduce the amount of water that is absorbed through the surface.
There are two types of sealers that can be applied to exterior concrete to reduce freeze-thaw damage, a Silane-Siloxane water repellent sealer, and an acrylic sealer.
Silane-Siloxane water repellent sealers, like the Armor SX5000 and Armor SX5000 WB chemically react with the concrete to form a hydrophobic barrier within the pores that will reduce the absorption of water by up to 95%. Water will be kept closer to the surface and freeze above the concrete, instead of below it. If you want to stop the concrete from re-freezing on the surface once the de-icing salts are applied, you can simply broom the water off the surface, away from the concrete. Silane-Siloxane sealers are the most chemical resistant sealers to Chlorides and other deicing chemicals.
While Silane-Siloxane sealers work below the surface, acrylic sealers are designed to work on the surface. Acrylic sealers like the Armor AR350, Armor AR500, and Armor WB25, bond to the concrete and leave behind a visible surface film that stops water from penetrating through the surface. Water will freeze on top of the acrylic sealer, instead of inside the pores of the concrete. If you want to stop the concrete from re-freezing on the surface once the de-icing salts are applied, you can simply broom the water off the surface, away from the concrete.
Silane-Siloxane sealers and acrylic sealers are great options for reducing freeze-thaw damage to concrete. Which sealer you use will depend on what you want your concrete to look like once sealed, how often you want to reseal your concrete, and what you need the sealer to offer in terms of performance.
If you aren’t sure which sealer is best for your concrete, don’t hesitate to reach out to a Foundation Armor technician and they can help you make the best sealer choice for your concrete.