If your business is outdoors and you have concrete work to do in all kinds of weather, you can’t afford to let cold temperatures keep you from doing your job. There will be times when you have to consider temporary heating solutions and here are some of the options you may want to check out.
Problems with Concrete and the Cold
Pouring concrete in the cold can result in a number of problems, because moisture in the concrete can freeze before it sets up. This can affect the curing process and ruin an otherwise excellent concrete pouring job. This is why the ground needs to be warm and when temperatures are below 40 F for several days, the ground may be too cold to pour.
Heating Concrete
Here are several possible temporary heating solutions and they come with advantages and disadvantages.
Reducing Water Content
This may seem like a good idea but it can actually delay the time it takes for the mix to set.
How Water
Hot water may work for a few hours but you could be taking major chances with your work. If the temperatures are far below freezing, this is not really an option.
Chemical Accelerators
The colder the weather, the colder your poured concrete will be. In some cases, it’s possible to use a small amount (two percent by volume) of calcium chloride in the mix. This can accelerate the process of hydration and the faster the concrete absorbs moisture the quicker it will set up. However there are two drawbacks with this strategy.
1. Steel embedded in the concrete (like rebar) may rust and corrode and this could possibly weaken a structure over time.
2. Surface color of the concrete can become spotted and if you are pouring colored concrete this can be a major issue.
Non chloride accelerators are available but they can be expensive. Plus, it is important to remember, accelerators do not keep concrete from freezing. They only speed up the process of hardening.
Ground Thaw Heaters
Large gas or oil powered heating units can provide some of the most effective temporary heating solutions. They keep the ground and concrete above the freezing mark so it can cure properly. Since the first 24 hours is the most critical time, there may be no need for heating after one day. Modern heating units are designed for efficiency and ease of operation, making them simple and cost effective.
