what can I add to premixed bags of concrete to prevent freezing?And where can I get it?

Answer 1

I assume you mean after concrete poured
You can lay a plastic membrane at bottom and up sides of boxing, cover poured concrete with tarps or use an accelerator to mix which which makes it go off much quicker
or as Brickie says use heat
I have used these different methods depending on the circumstances sometimes a combination
Eg after concrete has skinned sufficently lay light timber from edge to edge of boxing, lay tarp over top and use a small fan heater to put warm air under tarp, this provides a warm air barrier

Answer 2

I'm not sure where in the world you are but in the UK there is a troduct called "Febmix" which prevents freezing during setting.

I'm sure there are product that do the same job everywhere else in the world. Try asking at your local builders merchant

Look here for info http://www.toolbase.org/Technology-Inventory/Foundations/concrete-admixtures

Answer 3

if your talking about the bags were you just add water then it wont freeze as their will be no water to freeze, but probably best to keep in your garage, just in case it rains.

Answer 4

It shouldn't freeze if it's in powder form. Store it some place dry.

Answer 5

check at a cement company, or use rv antifreeze as the water, iv done this,

Answer 6

heat, most additives are ok but i tend to stay away from them if i can use heat...