THE CORE.

JAN

15



POURING CONCRETE IN COLD WEATHER

With winter in full swing, snow falling on the ground and temperatures dropping drastically, outdoor working conditions can be challenging. Consider the concrete industry, the businesses that still operate by producing and supplying concrete in conditions like these. Here are a few commonly asked questions regarding concrete and cold weather:

Is it okay to pour concrete in cold weather?

You can pour in cold weather, as long as certain precautions are taken. Concrete set time at 21 degrees celcius is approximately 5 hours; at 10 degrees celcius it is 10 hours; at minus 1 degree celcius it is up to 20 hours, and that’s if the concrete doesn’t freeze.

What temperature is too cold for concrete?

Any time you have three consecutive days where the average daily temperature is less than 5°C, or if the temperature is lower than -12°C for even half of any of those three days, that is considered undesirably cold for concrete. There are special precautions that need to be taken when placing, finishing, curing, and protecting concrete. Pouring concrete in cold weather can have a detrimental affect on the concrete curingprocess.

What happens if concrete freezes?

When concrete achieves 500 psi compressive strength, hydration of the cement has consumed enough of the water in the original mix so that even if the concrete does freeze, there's not enough water left in the pores to damage the concrete.

6 Things to avoid when working with concrete in cold weather:

·         Don’t pour on frozen ground

·         Using cold tools

·         Not using heaters

·         Sealing concrete when it is too cold

·         Misjudging daylight

·         Not using real-time temperature sensors

If you have any questions regarding pouring concrete in cold weather or for any other topics, please visit us at www.torontoredi-mix.com or call us at 416.798.7050 to speak with one of our concrete experts.

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