Avoid Unnecessary Costs and Delays During Cold Weather Concreting
7 Things to Avoid When Working With Concrete in Cold Weather
Although contractors might wish they didn’t have to work in cold weather, construction doesn’t stop when temperatures drops. To help you be better prepared, take a look at these 7 common mistakes to avoid during cold weather concreting.
1. Pouring Concrete on Frozen Ground
One of the biggest mistakes in concrete placement is placing concrete on frozen ground. Frozen ground can settle when thawed, causing the concrete to crack. Second, the fresh concrete closest to the ground will cure slower than the surface, resulting in the top setting and the bottom staying soft.
2. Using Cold Tools
It is just as important to keep your tools and buildings materials warm as it is the concrete. If forms or tools are cold, it could alter the concrete that comes into contact with them.
3. Not Using Heaters
As you probably know, the warmer the concrete, the faster it cures. When allowing fresh concrete to cure in the cold, the curing can stop altogether. Portable heaters deliver heat into the ground or into a concrete pour, so you can work through winter. Be careful when using heat; improperly heating the concrete can result in a weak structure.
4. Sealing Concrete When it’s Too Cold
If you are placing concrete in cold weather, it is advised to get a proper recommendation from the producer/manufacturer before sealing. Sealing typically should not be done if the temperature is below 10°C.
5. Misjudging Daylight
During cold weather months, the amount of daylight lessens. It is essential to use your time wisely, as running behind schedule could lead to more problems. Daylight will not only give you an abundance of light, it will also give warmer temperatures. If the concrete must be poured before or after the sun has passed, be sure to follow #3 on this list.
6. Allowing your Concrete to Freeze
Concrete should be kept warm (around 10°C), in order to cure properly. Fresh concrete can freeze at -4°C, so it is important to warm fresh concrete until it has the proper compressive strength measurement.
7. Not Using Real-time Temperature Sensors
Temperature monitoring in cold weather is important to ensure the production of high-quality concrete that meets temperature specifications and avoids the above problems. Among these problems are the freezing of concrete in early stages, lack of required strength, rapid temperature changes, inadequate protection of the structure and its serviceability, and improper curing procedures. These problems can be avoided by taking special precautions to ensure optimal temperature of concrete is maintained during the curing stages and observing a few principles such as protecting concrete from freezing and ensuring little or no external moisture is added unless located in a heated enclosure. It is up to the manager’s discretion to decide whether operating during cold weather will be possible without any issues or if it is wiser to wait for warmer temperatures, and to guarantee the quality of the work being produced.
*” Editor’s Note: This post was originally published in October 2017 and has been updated for accuracy and comprehensiveness.”