Normas

Designation: C 494/C 494M – 99ae1

Standard Specification for

Chemical Admixtures for Concrete1
This standard is issued under the fixed designation C 494/C 494M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.

e1 NOTE—Range value in 12.2.2 was editorially corrected July 2001.

1. Scope
1.1 This specification covers materials for use as chemical admixtures to be added to hydraulic-cement concrete mixtures in the field for the purpose or purposes indicated for the seven types as follows:
1.1.1 Type A—Water-reducing admixtures,
1.1.2 Type B—Retarding admixtures,
1.1.3 Type C—Accelerating admixtures,
1.1.4 Type D—Water-reducing and retarding admixtures,
1.1.5 Type E—Water-reducing and accelerating admixtures,
1.1.6 Type F—Water-reducing, high range admixtures, and
1.1.7 Type G—Water-reducing, high range, and retarding admixtures. 1.2 This specification stipulates tests of an admixture with suitable concreting materials as described in 11.1-11.3 or with cement, pozzolan, aggregates, and an air-entraining admixture proposed for specific work (11.4). Unless specified otherwise by the purchaser, the tests shall be made using concreting materials as described in 11.1-11.3.

requirements of this specification does not constitute assurance of acceptibility of the admixture for use in prestressed concrete.

1.3 This specification provides for three levels of testing.
1.3.1 Level 1—During the initial approval stage, proof of compliance with the performance requirements defined in
Table 1 demonstrates that the admixture meets the requirements of this specification. Uniformity and equivalence tests of
Section 6 shall be