Calcium Chloride Concrete Additive

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.

But many specifications prohibit its use. 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. Use this material when a rapid set is desired or when a quick return or access for the area is required. Aci318 08 building code requirements for structural concrete with some exceptions allows calcium chloride as an accelerating admixture for cast in place concrete.

The beneficial effects of calcium chloride will be even more pronounced at lower temperatures. Calcium chloride was used as an accelerating admixture in concrete up until the mid 1970s. Also used when freezing temperatures are anticipated. This is unfortunate because calcium chloride is the most efficient and least expensive accelerator used in concrete.

In the hydrate form it contains about 25 by weight of water of crystallisation. But its use may be limited by building codes or prohibited by some specifications. Reduced final set time. If dry calcium chloride is used it should be.