Otherwise it should be added at the job site mixing for at least three minutes or 30 revolutions of the mixer whichever is longer.
Calcium chloride concrete additive.
Sakrete cement mix accelerator is a calcium chloride based product designed to accelerate the set time of concrete mortar or any laporte cement based product.
Aci318 08 building code requirements for structural concrete with some exceptions allows calcium chloride as an accelerating admixture for cast in place concrete.
This is unfortunate because calcium chloride is the most efficient and least expensive accelerator used in concrete.
Calcium chloride was used as an accelerating admixture in concrete up until the mid 1970s.
The beneficial effects of calcium chloride will be even more pronounced at lower temperatures.
When ready mixed concrete is used calcium chloride should be added at the plant site if the concrete is to be discharged within one hour after the start of mixing.
If dry calcium chloride is used it should be.
Use this material when a rapid set is desired or when a quick return or access for the area is required.
Also used when freezing temperatures are anticipated.
But many specifications prohibit its use.
In the hydrate form it contains about 25 by weight of water of crystallisation.
Calcium chloride is the most effective and least expensive cold weather accelerator for concrete.