# Too cold to pour concrete sidewalk?



## haskl33 (Apr 17, 2006)

Is it too cold now to pour a sidewalk in central illinois. The sidewalk would go through the grass in the backyard from the garage to the deck in the back of the yard (approximately 30 ft). Any suggestions?


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## mdshunk (Mar 13, 2005)

It's never too cold. Have antifreeze mixed in the concrete and cover it with the insulated tarps, and it will "self heat".


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## K2 (Jul 8, 2005)

Blanket the open area but you can't pour flatwork on more than about a quarter inch of frozen ground. 
Calcium or Hi- Early are accelerators more than an antifreeze. The faster hydration occurs the more heat that is produced and blankets over top can hold the heat. The cure changes from about 28 days to 7 days more or less. Calcium is not allowed on govt. jobs and hi-early is sometimes allowed. Calcium eats the steel. 

That's the basic story where i live. It might be different in other parts of the country. I would never do flatwork below 10 degrees f. night temps and never do walls below 0 degrees night temps.

Blankets are bulky, generally dirty, and always a pain in the butt. If you own them they need to be stored for most of the year and when you need them they are full of dirt, leaves, and mice. If your in a windy area you have to make sure they are secured through a couple of nights or your work is lost. 

Generally on a sunny day I would take the blankets off and let the sun hit the slab and then cover again at night.

The second night after a pour has the greater risk of freezing. The reaction has slowed producing less heat but there are still plenty of complete water molecules left.


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## POOLMANinCT (Oct 7, 2006)

antifreeze? thats a new one to me. 
do tell...
ty


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## mdshunk (Mar 13, 2005)

CPSpool said:


> antifreeze? thats a new one to me.
> do tell...
> ty


Just a slang term for whatever the batch plant chooses to use in your area. As in, when I order concrete in the winter and they ask me, "Do you want anti-freeze in that?", and I say "Yes." You didn't think I meant automotive antifreeze, did you? :jester:


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## POOLMANinCT (Oct 7, 2006)

I didnt know what you meant, prestone etc(?)
im from the mind-set if you dont know ask.

thanks for clarification

ray


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## Guest (Dec 4, 2006)

We did a pour yesteday and they forgot the anitfreez, so today we spent the day ripping it out, fun stuff, 6'' slab, 50' by 75'.


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## Joasis (Mar 28, 2006)

We poured a 30 yard, 6 inch floor, about 1500 sq/ft Wednesday before Thanksgiving....3 pm pour, I was machining at 10pm. I paid a little extra for acclerator and 3500psi mix...the floor is perfect, and the temp held at 40 degrees that night. I know others do, but in Oklahoma, I don't have to pour in freezing weather....we can wait for a window of above freezing temps.


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## tkle (Apr 15, 2006)

I poured on wet frozen ground once.Watched the water bubble up as the hot concrete melted the ground.Not a good thing.


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