Concrete Outside Temp

[loudhornsrule]

I know winter is coming, but how cold is too cold to pour a slab? I live in North Texas. Thanks

 

[AWSubie]

No less than 50’F unless you use insulating blankets.

 

[EddieWalker]

50 degrees is the line. If it's colder, you have to add chemicals to the mix.

 

[Streetcar]

32degrees, you are only worried about excess water in the mix freezing before concrete reaches strength to resist force of freezing water

 

[Cord]

I know winter is coming, but how cold is too cold to pour a slab? I live in North Texas. Thanks

I've had slabs poured in below freezing weather, but you have to take extra steps to protect it. Several years ago we did a concrete building where several pours were exposed to -20 temps 48 hours after pouring. If you are in North Texas you'll be fine.

 

[Snobdds]

Contractors pour concrete in Wyoming all year long. The only time they stop is for snow, cold is viewed as just another day. Blankets are a must.

You will be fine anytime you pour, just adept to the temps and your fine.

 

[Streetcar]

Also do not pour concrete on frozen ground.

 

[Tractor Seabee]

No less than 50’F unless you use insulating blankets.

The key is maintaining the concrete temperature at 50 degrees F. Early stags of hydration generate heat so maintaining that is essential for proper hydration of the cement hence adding blankets as soon as finishing is done. Lift the blankets ahead of saw cutting minimizing exposure. ACI has a whole specification on cold weathering contracting.

Ron

 

[Ford850]

It's 19 degrees, with a wind chill of 8 right now, and there's a concrete truck in my drive. My neighbor's pouring a patio slab and is using my drive for the truck to deliver the load for easier access.

 

[Industrial Toys]

The guy next door had a floor poured in his pole barn a week ago. I told him to tell the contractor, no calcium! It was hovering around freezing. He did use some other chemical and I was surprised how quick it set up.

I have cast concrete in the cold and it took forever to set up. If concrete gives off heat to set, you would think cold would be good.

 

[newbury]

They are not saying it can't be done, just that you need to take precautions (thawed soil, blankets, additives etc.) for it to be done RIGHT.

I've been doing some concrete patching in Northeast Mississippi. When I got down here in early October it was almost too hot, now it's jumped to too cold. But I can wait till March.

I'm sure the OP could pour his pad with all the right stuff at any time of year. But at what cost to do it right? Or would he be better off if he waited till spring?

 

[Tractor Seabee]

There is a whole science built around concrete. ACI and the Army Corps of Engineers have been studying and experimenting with concrete mix deigns and ancillary methods since their inception. The USACE Experimental Station in Vicksburg is a fascinating place. I took a 2 week course on concrete inspection there when I was a Construction QA Specialist for the US Navy. There are many books written on the subject over the years. Most structural concrete today is totally unrecognizable from concrete cast 20-30-50 years ago. Constantly evolving. Unfortunately there are no new dams being built of the magnitude of the past. In my 65 year construction related career I have seen my share of success and failures. Most failures are due to improper methodology and refusal to embrace current technology.

Ron