ASTM C494/C494M-15

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:C494/C494M −15
StandardSpecification for
1
Chemical Admixtures for Concrete
This standard is issued under the fixed designation C494/C494M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
NOTE 3—Admixtures that contain relatively large amounts of chloride
1. Scope*
may accelerate corrosion of prestressing steel. Compliance with the
1.1 This specification covers materials for use as chemical
requirements of this specification does not constitute assurance of accept-
admixtures to be added to hydraulic-cement concrete mixtures ability of the admixture for use in prestressed concrete.
in the field for the purpose or purposes indicated for the eight
1.3 This specification provides for three levels of testing.
types as follows:
1.3.1 Level 1—During the initial approval stage, proof of
1.1.1 Type A—Water-reducing admixtures,
compliance with the performance requirements defined in
1.1.2 Type B—Retarding admixtures,
Table 1 demonstrates that the admixture meets the require-
1.1.3 Type C—Accelerating admixtures,
mentsofthisspecification.Admixtures(exceptforTypesB,C,
1.1.4 Type D—Water-reducing and retarding admixtures,
E, and S) shall qualify for provisional compliance when the
1.1.5 Type E—Water-reducing and accelerating admixtures,
physical requirements and any of the alternative compressive
1.1.6 Type F—Water-reducing, high range admixtures,
strength requirements in Table 1 are met. If subsequent test
1.1.7 Type G—Water-reducing, high range, and retarding
results at six months or one year fail to meet the standard
admixtures, and
requirement of 100% of reference strength, the compliance of
1.1.8 Type S—Specific performance admixtures.
theadmixturetothisstandardiswithdrawnandallusersofthe
admixture shall be notified immediately. Uniformity and
1.2 This specification stipulates tests of an admixture with
equivalence tests of Section 6 shall be carried out to provide
suitableconcretingmaterialsasdescribedin11.1–11.3orwith
results against which later comparisons can be made (see Note
cement, pozzolan, aggregates, and an air-entraining admixture
4).
proposed for specific work (11.4). Unless specified otherwise
by the purchaser, the tests shall be made using concreting
NOTE 4—Allowing for provisional compliance while retaining longer
materials as described in 11.1 – 11.3.
termcompressivestrengthrequirementspromotesmorerapidqualification
of new materials, but also provides assurance that new admixture
NOTE 1—It is recommended that, whenever practicable, tests be made
technologies will not exhibit unexpected longer term performance. The
using the cement, pozzolan, aggregates, air-entraining admixture, and the
alternative compressive strength requirements in Table 1 are based on
mixture proportions, batching sequence, and other physical conditions
statisticalanalysisof103SpecificationC494/C494Mevaluationtests.The
proposedforthespecificwork(11.4)becausethespecificeffectsproduced
alternative requirements correspond to a 99% probability of passing
by chemical admixtures may vary with the properties and proportions of 2
subsequent test age requirements.
the other ingredients of the concrete. For instance, Types F and G
1.3.2 Level 2—Limited retesting is described in 5.2 – 5.2.2.
admixturesmayexhibitmuchhigherwaterreductioninconcretemixtures
having higher cement factors than that listed in 12.1.1. Proof of compliance with the requirements of Table 1 demon-
Mixtures having a high range water reduction generally display a
stratescontinuedconformityoftheadmixturewiththerequire-
higher rate of slump loss.When high-range admixtures are used to impart
ments of the specification.
increased workability (6 to 8-in. slump [150 to 200–mm]), the effect may
1.3.3 Level 3—For acceptance of a lot or for measuring
be of limited duration, reverting to the original slump in 30 to 60 min
uniformity within or between lots, when specified by the
depending on factors normally affecting rate of slump loss. The use of
chemical admixtures to produce high-slump (flowing) concrete is covered
purchaser, the uniformity and equivalence tests of Section 6
by Specification C1017/C1017M.
shall be used.
NOTE 2—The purchaser should ensure that the admixture supplied for
1.4 The values stated in either SI units or inch-pound units
use in the work is equivalent in composition to the admixture subjected to
test under this specification (see Section 6, Uniformity and Equivalence). are to be regarded separately as standard. The values stated in
each system may not be exact equivalen
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