ASTM C494/C494M-15a
(Specification)Standard Specification for Chemical Admixtures for Concrete
Standard Specification for Chemical Admixtures for Concrete
ABSTRACT
This specification covers the materials and the test methods for use in chemical admixtures to be added to hydraulic-cement concrete mixtures in the field. The seven types of admixtures are indicated as follows: Type A—water reducing; Type B—retarding; Type C—accelerating; Type D—water reducing and retarding; Type E—water reducing and accelerating; Type F—water reducing, high range; and Type G—water reducing, high range, and retarding. The materials used in the concrete mixtures shall include Type I or Type II cement, pozzolan, fine and coarse aggregates, and air-entraining admixture. Samples of freshly mixed concrete from at least three separate batches for each condition of concrete shall be tested in accordance with the slump, air content, time of setting, and water content tests. Physical properties retesting shall consist of uniformity and equivalence tests using infrared analysis which is intended to compare qualitatively the composition of different samples, residue by oven drying which shall be either a forced circulation type or one with provision for free access of air, and specific gravity determination using hydrometers. Test specimens of the hardened concrete shall be prepared in accordance to compressive strength, flexural strength, resistance to freezing and thawing, and length change.
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 eight 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,
1.1.7 Type G—Water-reducing, high range, and retarding admixtures, and
1.1.8 Type S—Specific performance 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 C1017/C1017M.
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 require...
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Designation:C494/C494M −15a
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
useintheworkisequivalentincompositiontotheadmixturesubjectedto
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 equivalents; therefo
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C494/C494M − 15 C494/C494M − 15a
Standard Specification 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. A number 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.
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 eight 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,
1.1.7 Type G—Water-reducing, high range, and retarding admixtures, and
1.1.8 Type S—Specific performance 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
C1017/C1017M.
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, E, and S) shall
qualify for provisional compliance when the physical requirements and any of the alternative compressive strength requirements
in Table 1 are met. If subsequent test results at six 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 4—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 Table 1 are based on statistical analysis of 103 Specification C494/C494M evaluation tests. The alternative requirements
2
correspond to a 99 % probability of passing subsequent test age requirements.
1
This specification is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.23 on
Chemical Admixtures.
Curren
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