Freezing temperatures create a different environment for new concrete in the winter, so you need to be careful when you are pouring and caring for your concrete. Here are three things you will need for keeping your new cement in good condition through its first winter.
The Right Cement Mixture
Warm temperatures are not always available when you need to pour new cement. Sometimes you may need to pour cement in the winter, when temperatures outside are near freezing or below zero. When you can't change the cold weather, then you need to adjust the mixture of cement to allow for freezing temperatures.
When you pour cement, it needs to be above 40 degrees F for the cement to undergo its chemical change to harden and cure. If cement is at 50 degrees or below when you pour it, it can take a lot longer to set. For this reason, many concrete companies use hot water when they mix their concrete mixture. This allows the mixture to be a little bit warmer, so when it is poured into the cement forms, the cement retains much of the heat within itself so it can set better.
You can speed up the cement's cure time by adding an accelerator such as calcium chloride. Or you can add an air entraining mixture into the cement. This mixture will give your cement tiny air pockets where the moisture inside the cement will have space to expand as it freezes. You can also increase the amount of cement used in your concrete mixture to increase its cure time.
In a situation where you need to pour cement in temperatures that are below zero, you can use a cement blanket to keep heat inside the cement until it can set. A cement blanket can insulate to keep the cement warm when the outside temperature is 32 degrees F and below.
By pouring heated cement into the forms, then covering it with a polypropylene foam cement blanket, the cement will stay warm with the heat trapped under the blanket. And, using a cement blanket along with the right cement mixture, your cement will cure properly within a few days. You can read more about how concrete blankets help the curing process by following the link.
Safe Ice Melt
Once your new cement is completely set and cured, make sure you don't do damage to your cement over the winter. For the first winter, it is a good idea to avoid using any ice melting products. The chemicals in these products can weaken your concrete's structure, increasing the chances for it to crack or chip later on.
Rather than skating across any ice covering your cement for the first winter, you can spread a fine layer of sand or gravel on top of the ice over your new cement. These safe materials will help you gain traction when you walk or drive over the icy pavement, without causing permanent damage to its surface.
After your new cement has made it through its first winter unharmed, it will be strong enough for you to use ice melting products.
The best type of ice melt, that won't damage your cement, is one that is made with calcium chloride. Calcium chloride pulls in moisture from nearby surfaces to make more brine, and help speed up the melting of the ice.
An important part of calcium chloride that makes it so safe to use on concrete is the temperature range in which it will melt ice. Calcium chloride will continue to keep ice melted to -25 degrees F. Other ice melting chemicals stop melting the ice when the temperature falls below a certain point, then they allow the water to refreeze. When the water refreezes inside all the tiny pores of your concrete, it expands, damaging your concrete. When the water remains thawed to -25 degrees F, your concrete will not be damaged in lower temperatures.
Magnesium chloride only melts ice until the temperature falls to 0 degrees F, and potassium chloride only melts ice until the temperature falls to 25 degrees F.
Following these three recommendations to protect your concrete will ensure it cures and stays in good condition through each winter.