Found a weird trick for pouring concrete in cold weather

We were pouring a slab outside a strip mall in Denver last October. Temperature dropped faster than the forecast said. My foreman told me to add a little bit of calcium chloride to the mix. I thought he was joking because we never use accelerators. He said just do it or we'd be chipping out frozen concrete by morning. The mix set up fine and didn't crack. No idea why more crews don't do that around here. Anyone else use accelerators on the regular or is this just a Midwest mountain thing?

2 comments

2 Comments

rosep8727d ago

Calcium chloride isn't really a mountain thing, it's pretty common practice anywhere you might frost. Just don't use too much or it can cause the rebar to corrode faster.

kai65727d ago

Wait, is it really that common even in places with mild winters? I always assumed that stuff was mainly for preventing frost heave in colder climates. But yeah, I've heard the rebar thing too. A buddy of mine used too much on a walkway and had to rip it out after a couple years because the steel inside was all rusted and cracking the concrete. It's one of those things where a little goes a long way, and you really gotta measure it out careful.