The construction season forges onward through the winter.
Cold weather and snow on the ground signals the end of a construction season to most. However, that just isn’t the case with new materials and technologies that extend the ability to construct right into the winter months.
At Lafarge, we have developed concrete mixtures appropriate for the changing climates of Canada. Suitable for cold weather conditions, WeatherMix is a contractor's best friend when time is of an essence for a project.
WeatherMix can be placed just like regular concrete: with a truck chute, basket, conveyor or pump at temperatures as low as -7.2 degrees celsius, with unique formulations designed for six different temperature ranges.
Here are a few FAQ’s for using WeatherMix:
Q: What is Cold Weather Concrete?
A: Weather conditions can have a dramatic effect on both the setting and concrete placement, finishing and protection systems. Cold weather concrete combats these effects by allowing the mix to gain strength and set in an appropriate amount of time, and protects against freezing and thawing.
Lafarge’s brand of cold weather concrete, Weathermix, offers accelerated setting time leading to earlier finishing of slabs and lower labour costs for contractors. It also contains a non-Chloride based accelerator.
Q: What risk do I run by not ordering Cold Weather Concrete?
A: Concrete that is allowed to freeze while in its plastic state can have its potential strength reduced by more than 50% and its durability properties will be dramatically reduced. The risk is possibly compromising to the strength the concrete can gain if it is frozen before it reaches at least 3.5 MPa.
Q: Is there any additional considerations to make when working with Cold Weather Concrete?
A: Do not place concrete on a frozen subgrade. This means you may need to thaw the subgrade with steam or protect it with insulation.
Provide triple insulation thickness at the corners and edges of walls and slabs. All proper sub-grade heating and hoarding practices must still be followed when using cold weather concrete.
Don't expose concrete surfaces to a sudden temperature drop; gradually reduce the insulation or enclosure temperature to control concrete cooling (no more than a 50 degree F drop in 24 hours).
It is good practice in cold weather to leave forms in place as long as possible. Even within heated enclosures, forms serve to distribute heat more evenly and help prevent drying and local overheating.