Changed my mind about using accelerators in cold weather pours

I used to be DEAD SET against putting calcium chloride in my concrete mix for winter jobs. Thought it was cheating and messed with the final strength. Then last January at a job site in Boulder, Colorado, the temp dropped to 15 degrees overnight and I had 40 yards of slab that wasn't even close to setting up. My old timer buddy Joe talked me into trying it and that pour finished fine the next morning with no cracking. Has anyone else switched their stance on accelerators after a bad freeze scare?

2 comments

2 Comments

the_susan26d ago

So did Joe give you a ratio to follow or did you just wing it based on how cold it was? I've always been curious about the fine line between helping it set and overdoing it.

riley_miller2526d ago

Joe didn't give me any fancy ratio, he just dumped a bag in and said "this oughta do it" which is pretty much how he does everything. We ended up using way less than I thought we'd need because the cold snap wasn't as harsh as predicted, but it still did the job. I figure if you're worried about overdoing it, err on the side of too little and just watch it like a hawk, 'cause too much turns your concrete into a crumbly mess. My biggest fear is ending up with a slab that looks like a giant biscuit instead of a floor, so I'm careful. These days I keep a small bag in my truck just for peace of mind, even if I don't end up using it.