Method for Curing Concrete
After following our tips for pouring concrete in cold weather, your concrete has been placed and you’re ready to protect and cure it. What’s the next step? The traditional, tried-and-true method for curing concrete in cold weather is to cover it with blankets. This method is successful even if the air temperature falls below 20°F. Between the ground temperature, the heat generated by the concrete, and the insulation of the blankets, it’s enough to protect the concrete as it cures. Cold weather techniques are necessary whenever you’re working in a climate where the air temperature is below 40°F.
Regardless of the weather, part of the process when curing concrete is waiting for the bleed water to evaporate. As the concrete particles begin to settle, they push out any water that wasn’t absorbed during the hydration process. The bleed water is that excess that collects on the surface of the concrete. It’s important to let the bleed water evaporate, because the surface of your concrete will be weakened if any bleed water is finished into it. When it’s cold out, the concrete will set more slowly, which means the bleeding will start later and last longer. An alternative to waiting is trying to squeegee or vacuum some of the bleed water off, but more often than not you just have to wait.
If the concrete is kept at 50°F or warmer, you’ll only need to keep it covered with blankets for a couple of days. You can measure the temperature of your concrete by using an infrared temperature gun. The insulation that you’ll require to keep your concrete at 50°F will depend on how thick the concrete is, what the mix is made from, and the lowest you expect the air temperature to drop during the curing process.
You should wrap any rebars that are sticking out from the covered area, and secure the blankets so they won’t blow off overnight. Also, triple the layers of insulation at the corners or edges where freezing may occur.
Check back with us for more cold weather concrete curing tips.