ASTM C494/C494M-05
(Specification)Standard Specification for Chemical Admixtures for Concrete
Standard Specification for Chemical Admixtures for Concrete
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.
Note 1—It is recommended that, whenever practicable, tests be made using the cement, pozzolan, aggregates, air-entraining admixture, and the mixture proportions, batching sequence, and other physical conditions 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 ingredients 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 [150 to 200-mm]), 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 acceptability 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. Admixtures (except for Types B, C, and E) shall qualify for provisional compliance when the alternative compressive strength requirements in Table 1 are met. If subsequent test results at 6 months or one year fail to meet the standard requirement of 100 % of reference strength, the compliance of the admixture to this standard is withdrawn and all users of the admixture shall be notified immediately. Uniformity and equivalence tests of Section 6 shall be carried out to provide results against which later comparisons can be made (See Note 4).
Note 0&38212;Allowing for provisional compliance while retaining longer term compressive strength requirements promotes more rapid qualification of new materials, but also provides assurance that new admixture technologies will not exhibit unexpected longer term performance. The alternative compressive strength requirements in are based on statistical analysis of 103 Specification C 494/C 494M evaluation tests. The alternative requirements correspond to a 99 % probability of passing subsequent test age requirements.
1.3.2 Level 2—Limited retesting is described in 5.2, 5.2.1 and 5.2.2. Proof of compliance with the requirements of demonstrates continued conformity of the admixture with the requirements of the specification.
1.3.3 Level 3—For acceptance of a lot o...
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C 494/C 494M – 05
Standard Specification for
1
Chemical Admixtures for Concrete
ThisstandardisissuedunderthefixeddesignationC494/C494M;thenumberimmediatelyfollowingthedesignationindicatestheyear
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 (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.
NOTE 2—The purchaser should ensure that the admixture supplied for
1. Scope
use in the work is equivalent in composition to the admixture subjected to
1.1 This specification covers materials for use as chemical
test under this specification (see Section 6, Uniformity and Equivalence).
admixtures to be added to hydraulic-cement concrete mixtures
NOTE 3—Admixtures that contain relatively large amounts of chloride
in the field for the purpose or purposes indicated for the seven
may accelerate corrosion of prestressing steel. Compliance with the
types as follows: requirements of this specification does not constitute assurance of accept-
ability of the admixture for use in prestressed concrete.
1.1.1 Type A—Water-reducing admixtures,
1.1.2 Type B—Retarding admixtures,
1.3 This specification provides for three levels of testing.
1.1.3 Type C—Accelerating admixtures,
1.3.1 Level 1—During the initial approval stage, proof of
1.1.4 Type D—Water-reducing and retarding admixtures,
compliance with the performance requirements defined in
1.1.5 Type E—Water-reducing and accelerating admixtures,
Table 1 demonstrates that the admixture meets the require-
1.1.6 Type F—Water-reducing, high range admixtures, and
mentsofthisspecification.Admixtures(exceptforTypesB,C,
1.1.7 Type G—Water-reducing, high range, and retarding
and E) shall qualify for provisional compliance when the
admixtures.
alternative compressive strength requirements in Table 1 are
1.2 This specification stipulates tests of an admixture with
met. If subsequent test results at 6 months or one year fail to
suitable concreting materials as described in 11.1-11.3 or with
meet the standard requirement of 100% of reference strength,
cement, pozzolan, aggregates, and an air-entraining admixture
the compliance of the admixture to this standard is withdrawn
proposed for specific work (11.4). Unless specified otherwise
and all users of the admixture shall be notified immediately.
by the purchaser, the tests shall be made using concreting
Uniformity and equivalence tests of Section 6 shall be carried
materials as described in 11.1-11.3.
out to provide results against which later comparisons can be
made (See Note 4).
NOTE 1—It is recommended that, whenever practicable, tests be made
using the cement, pozzolan, aggregates, air-entraining admixture, and the
NOTE 4—Allowing for provisional compliance while retaining longer
mixture proportions, batching sequence, and other physical conditions
termcompressivestrengthrequirementspromotesmorerapidqualification
proposedforthespecificwork(11.4)becausethespecificeffectsproduced
of new materials, but also provides assurance that new admixture
by chemical admixtures may vary with the properties and proportions of
technologies will not exhibit unexpected longer term performance. The
the other ingredients of the concrete. For instance, Types F and G
alternative compressive strength requirements in Table 1 are based on
admixturesmayexhibitmuchhigherwaterreductioninconcretemixtures
statistical analysis of 103 Specification C494/C494M evaluation tests.
having higher cement factors than that listed in 12.1.1.
The alternative requirements correspond to a 99% probability of passing
Mixtureshavingahighrangewaterreductiongenerallydisplayahigher 2
subsequent test age requirements.
rate of slump loss. When high-range admixtures are used to impart
1.3.2 Level 2—Limited retesting is described in 5.2, 5.2.1
increased workability (6 to 8-in. slump [150 to 200–mm]), the effect may
be of limited duration, reverting to the original slump in 30 to 60 min and 5.2.2. Proof of compliance with the requirements of Table
depending on factors normally affecting rate of slump loss. The use of
1demonstratescontinuedconformityoftheadmixturewiththe
chemical admixtures to produce high-slump (flowing) concrete is covered
requirements of the specification.
by Specification C1017.
1.3.3 Level 3—For acceptance of a lot or for measuring
uniformity within or between lots, when specified by the
purchaser, the uniformity and equivalence tests of Section 6
1
shall be used.
This specification is under the jurisdiction of ASTM Committee C09 on
Concrete Aggregates and is the direct responsibility of Subcommittee C9.23 on
Chemical Admixtures.
2
Current edition approved May 1, 2005. Published May 2005. Originally Supporting da
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.