Concrete Advice

sublauxation

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Oct 13, 2008
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Concrete question for you all, I'm building a bigger garage to fit the boat and my contractor is running way behind. Weather has been in the 20's to 40's and he wants to pour the driveway and an 8 inch curb around the garage to elevate the framing off the slab on Friday. (The garage slab was poured last week).

He wants to start framing the garage on Saturday which means that all the building materials will have to be delivered onto that driveway less than 24 hours after pouring and start building on those curbs right away.

He is using an early strengthening mix but even at that isn't this entirely too early? He's way behind schedule but to me this seems like a really bad way to make up time. Your thoughts???
 

alldodge

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early strengthening mix

That's a new term for me. Suggest calling the same or another concrete company and ask them. Don't mention your contractor just that it may be an issue or something like that
 

sam am I

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Far from a concrete expert but I think because curing will be much slower in colder weather as it needs to be kept at least >50F during its hydration, think the cure is a period for about 2 days/48hrs.

I do recall, back at band camp, a few days where we were pouring and it was -20F'ish (minus 20F), adding calcium chloride to help it cure much faster.

"Calcium chloride accelerates the rate of hydration of freshly placed concrete and lowers its free water content faster. This allows concrete to escape potential freeze damage in a matter of days, as opposed to the weeks it can take normally."

He's just saying he is having an chemical accelerator added which will have it "strengthen earlier" i.e., quick cure, and if he blankets it, (he should with those temps) he can pull the blankets off much faster to build on it. That's my interpretation anyway
 
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jimmbo

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May 24, 2004
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They pour a lot of Concrete in Subfreezing Temps up here, I don't know what else beside Calcium Chloride they add to the Mix, but it appears to be very strong when Cured. I know part of the CN Tower in Toronto, was poured during the winter, adding several feet to the Buildings Height every day
 

MTboatguy

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They build stuff around here year around with no problems at all, they use a hot mix, at least that is what they call it, so they can pour in sub freezing temps.

There is a lot of different mix combo's so they can deal with weather year around, just have to make sure you are using the right mix and things will turn out okay.
 

Bob_VT

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First off - due to my US Army Engineer background I have to say this......You PLACE concrete and you POUR tea. We were always given hell for that.

Calcium Chloride up to 2% can be added however, Since this is being placed on the ground - I would check the true ground temperature. The temperature of the ground might surprise you.

Yes when I built my garage I used 8" concrete block to form the lift for the walls.

Good luck with it.
 
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