ASTM C494/C494M-19

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 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 Unless specified otherwise by the purchaser, test specimens for qualifying an admixture shall be made using concreting materials as described in 11.1 – 11.3.  
Note 1: As discussed in Appendix X2, it is recommended that, whenever practicable, supplementary tests be made by the purchaser using the cement, pozzolan, aggregates, air-entraining admixture, and the mixture proportions, batching sequence, and other physical conditions proposed for the specific work because the specific effects produced by chemical admixtures may vary with the properties and proportions of the other ingredients of the concrete. For example, Types F and G admixtures may exhibit much higher water reduction in concrete mixtures having higher cement contents than that listed in 12.1.1.
Note 2: The purchaser should verify 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 sufficient amounts of chloride may accelerate corrosion of steel reinforcement. Compliance with the requirements of this specification does not constitute assurance of acceptability of the admixture for use in reinforced 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. Proof of compliance shall be based on comparisons of the average test results from the batches of test concrete and the average test results from the batches of reference concrete. Admixtures (except for Types B, C, E, and S) shall qualify for provisional compliance if the time of setting, length change, and durability factor meet the physical requirements and any of the alternative compressive strength requirements shown in parentheses in Table 1 are met through the date of provisional acceptance (see Note...

General Information

• Status: Historical
• Publication Date: 14-Dec-2019
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.23 - Chemical Admixtures

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:C494/C494M −19
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.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.
1. Scope* ments of this specification. Proof of compliance shall be based
on comparisons of the average test results from the batches of
1.1 This specification covers materials for use as chemical
test concrete and the average test results from the batches of
admixtures to be added to hydraulic-cement concrete mixtures
reference concrete.Admixtures (except for Types B, C, E, and
for the purpose or purposes indicated for the eight types as
S) shall qualify for provisional compliance if the time of
follows:
setting, length change, and durability factor meet the physical
1.1.1 Type A—Water-reducing admixtures,
requirements and any of the alternative compressive strength
1.1.2 Type B—Retarding admixtures,
requirements shown in parentheses in Table 1 are met through
1.1.3 Type C—Accelerating admixtures,
the date of provisional acceptance (see Note 4). If subsequent
1.1.4 Type D—Water-reducing and retarding admixtures,
test results at six months or one year fail to meet the
1.1.5 Type E—Water-reducing and accelerating admixtures,
requirement of at least 100% of reference strength, the
1.1.6 Type F—Water-reducing, high range admixtures,
provisional compliance of the admixture to this standard is
1.1.7 Type G—Water-reducing, high range, and retarding
withdrawn and all users of the admixture shall be notified
admixtures, and
immediately. Uniformity and equivalence tests of Section 6
1.1.8 Type S—Specific performance admixtures.
shall be carried out to provide results against which later
1.2 Unless specified otherwise by the purchaser, test speci-
comparisons shall be made.
mens for qualifying an admixture shall be made using concret-
NOTE 4—Allowing for provisional compliance while retaining longer
ing materials as described in 11.1 – 11.3.
termcompressivestrengthrequirementspromotesmorerapidqualification
NOTE 1—As discussed in Appendix X2, it is recommended that,
of new materials, but also provides assurance that new admixture
wheneverpracticable,supplementarytestsbemadebythepurchaserusing
technologies will not exhibit unexpected longer term performance. The
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
proposed for the specific work because the specific effects produced by
alternative requirements shown in parentheses correspond to a 99%
2
chemical admixtures may vary with the properties and proportions of the
probability of passing strength requirements at subsequent test ages, if
other ingredients of the concrete. For example,Types F and G admixtures
any one of the requirements is met. There is no requirement that all be
may exhibit much higher water reduction in concrete mixtures having
met.
higher cement contents than that listed in 12.1.1.
1.3.2 Level 2—Limited retesting is described in 5.2 – 5.2.2.
NOTE 2—The purchaser should verify that the admixture supplied for
useintheworkisequivalentincompositiontotheadmixturesubjectedto Proof of compliance with the requirements of Table 1 demon-
test under this specification (see Section 6, Uniformity and Equivalence).
stratescontinuedconformityoftheadmixturewiththerequire-
NOTE 3—Admixtures that contain sufficient amounts of chloride may
ments of the specification.
accelerate corrosion of steel reinforcement. Compliance with the require-
1.3.3 Level 3—For acceptance of a lot or for measuring
mentsofthisspecificationdoesnotconstituteassuranceofacceptabilityof
the admixture for use in reinforced concrete.
uniformitywithinorbetweenlots,ifspecifiedbythepurchaser,
theuniformityandequivalencetestsofSection6shallbeused.
1.3 This specification provides for three levels of testing.
1.3.1 Level 1—During the initial approval stage, proof of
1.4 The values stated in either SI units or inch-pound units
compliance with the performance requirements defined in
are to be regarded separately as standard. The values stated in
Table 1 demonstrates that the admixture meets the require-
eachsystemarenotnecessarilyexactequivalents;therefore,to
ensure conformance with the standard, each system shall be
used independently of the other, and values from the two
1
This specification is under the ju
...

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 − 17 C494/C494M − 19
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 test specimens for qualifying an admixture shall be made using concreting materials as described in 11.1 – 11.3.
NOTE 1—It As discussed in Appendix X2, it is recommended that, whenever practicable, supplementary tests be made by the purchaser 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,example, Types F and G admixtures may exhibit much higher water reduction in concrete mixtures having higher cement
factorscontents 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 ensureverify 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 sufficient amounts of chloride may accelerate corrosion of prestressing steel.steel reinforcement.
Compliance with the requirements of this specification does not constitute assurance of acceptability of the admixture for use in prestressedreinforced
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. Proof of compliance shall be based on comparisons
of the average test results from the batches of test concrete and the average test results from the batches of reference concrete.
Admixtures (except for Types B, C, E, and S) shall qualify for provisional compliance when the if the time of setting, length
change, and durability factor meet the physical requirements and any of the alternative compressive strength requirements shown
in parentheses in Table 1 are met. met through the date of provisional acceptance (see Note 4). If subsequent test results at six
months or one year fail to meet the standard requirement of at least 100 % of reference strength, the provisional 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 canshall be made (see made.
Note 4).
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 Admixtu
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