Standard Specification for CHEMICAL ADMIXTURES FOR CONCRETE
|Publication Date:||27 March 1986|
|ICS Code (Concrete and concrete products):||91.100.30|
This specification covers materials for use as chemical admixtures to be added to portland cement concrete mixtures in the field for the purpose or purposes indicated for the seven types as follows:
Type A - Water-reducing admixtures,
Type B-Retarding admixtures,
Type C-Accelerating admixtures,
Type D-Water-reducing and retarding admixtures,
Type E-Water-reducing and accelerating admixtures, 1.
Type F-Water-reducing, high range admixtures, and
Type G-Water-reducing, high range, and retarding admixtures.
This specification stipulates tests of an admixture with suitable concreting materials as described in 11.1 through 11.3 or with cement, pozzolan, aggregates, and an air-entraining admixture proposed for specific work (1104), Unless specified otherwise by the purchaser, the tests shall be. made using concreting materials as described in 11.1 through 11.3.
NOTE 1-It is recommended that, whenever practicable, tests be made using the cement, pozzolan, aggregates, air-entraining admixture, and the mixture proportions and batching sequence proposed for the specific work (11.4) because the specific effects produced by chemical admixtures may vary with the properties and proportions of the other ingre4ients of the concrete. For instance, types F and G admixtures may exhibit much higher water reduction in concrete mixtures having higher cement factors than that listed in 12.1.1.
Mixtures having a high range water reduction generally display a higher rate of slump loss. When high-range admixtures are used to impart increased workability (6 to 8-in. slump), the effect may be of limited duration, reverting to the original slump in 30 to 60 min depending on factors normally affecting rate of slump loss. The use of chemical admixtures to produce high-slump (flowing) concrete is covered by Specification C 1017.
NOTE 2-The purchaser should ensure that the admixture supplied for use in the work is equivalent in composition to the admixture subjected to test under this specification (see Section 6, Uniformity and Equivalence).
NOTE 3-Admixtures that contain relatively large amounts of chloride may accelerate corrosion of prestressing steel. Compliance with the requirements of this specification does not constitute assurance of acceptibility of the admixture for use in prestressed concrete.
The values stated in inch-pound units are to be regarded as the standard.