ASTM C231-08c

Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method

SIGNIFICANCE AND USE
This test method covers the determination of the air content of freshly mixed concrete. The test determines the air content of freshly mixed concrete exclusive of any air that may exist inside voids within aggregate particles. For this reason, it is applicable to concrete made with relatively dense aggregate particles and requires determination of the aggregate correction factor (see 6.1 and 10.1).
This test method and Test Method C 138/C 138M and C 173/C 173M provide pressure, gravimetric, and volumetric procedures, respectively, for determining the air content of freshly mixed concrete. The pressure procedure of this test method gives substantially the same air contents as the other two test methods for concretes made with dense aggregates.
The air content of hardened concrete may be either higher or lower than that determined by this test method. This depends upon the methods and amount of consolidation effort applied to the concrete from which the hardened concrete specimen is taken; uniformity and stability of the air bubbles in the fresh and hardened concrete; accuracy of the microscopic examination, if used; time of comparison; environmental exposure; stage in the delivery, placement and consolidation processes at which the air content of the unhardened concrete is determined, that is, before or after the concrete goes through a pump; and other factors.
SCOPE
1.1 This test method covers determination of the air content of freshly mixed concrete from observation of the change in volume of concrete with a change in pressure.
1.2 This test method is intended for use with concretes and mortars made with relatively dense aggregates for which the aggregate correction factor can be satisfactorily determined by the technique described in Section 6. It is not applicable to concretes made with lightweight aggregates, air-cooled blast-furnace slag, or aggregates of high porosity. In these cases, Test Method C 173/C 173M should be used. This test method is also not applicable to nonplastic concrete such as is commonly used in the manufacture of pipe and concrete masonry units.
1.3 The text of this test method references notes and footnotes that provide explanatory information. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.)

General Information

• Status: Historical
• Publication Date: 30-Sep-2008
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.60 - Testing Fresh Concrete

Relations

• Replaces: ASTM C231-08b - Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
• Effective Date: 01-Oct-2008
• Replaced By: ASTM C231-09 - Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
• Effective Date: 01-Jun-2009
• Referred By: ASTM C110-20 - Standard Test Methods for Physical Testing of Quicklime, Hydrated Lime, and Limestone
• Effective Date: 01-Oct-2008
• Referred By: ASTM C173/C173M-16 - Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
• Effective Date: 01-Oct-2008
• Referred By: ASTM C1646/C1646M-16 - Standard Practice for Making and Curing Test Specimens for Evaluating Resistance of Coarse Aggregate to Freezing and Thawing in Air-Entrained Concrete
• Effective Date: 01-Oct-2008

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:C231–08c
Standard Test Method for
Air Content of Freshly Mixed Concrete by the Pressure
1
Method
This standard is issued under the fixed designation C231; 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 Department of Defense.
1. Scope* C138/C138M Test Method for Density (Unit Weight),
Yield, and Air Content (Gravimetric) of Concrete
1.1 This test method covers determination of the air content
C172 Practice for Sampling Freshly Mixed Concrete
of freshly mixed concrete from observation of the change in
C173/C173M Test Method for Air Content of Freshly
volume of concrete with a change in pressure.
Mixed Concrete by the Volumetric Method
1.2 This test method is intended for use with concretes and
C192/C192M Practice for Making and Curing Concrete
mortars made with relatively dense aggregates for which the
Test Specimens in the Laboratory
aggregate correction factor can be satisfactorily determined by
C670 Practice for Preparing Precision and Bias Statements
the technique described in Section 6. It is not applicable to
for Test Methods for Construction Materials
concretes made with lightweight aggregates, air-cooled blast-
E177 Practice for Use of the Terms Precision and Bias in
furnaceslag,oraggregatesofhighporosity.Inthesecases,Test
ASTM Test Methods
Method C173/C173M should be used. This test method is
also not applicable to nonplastic concrete such as is commonly
3. Significance and Use
used in the manufacture of pipe and concrete masonry units.
3.1 This test method covers the determination of the air
1.3 The text of this test method references notes and
content of freshly mixed concrete. The test determines the air
footnotes that provide explanatory information. These notes
contentoffreshlymixedconcreteexclusiveofanyairthatmay
and footnotes (excluding those in tables and figures) shall not
exist inside voids within aggregate particles. For this reason, it
be considered as requirements of this standard.
is applicable to concrete made with relatively dense aggregate
1.4 The values stated in inch-pound units are to be regarded
particlesandrequiresdeterminationoftheaggregatecorrection
as standard. The values given in parentheses are mathematical
factor (see 6.1 and 9.1).
conversions to SI units that are provided for information only
3.2 This test method and Test Method C138/C138M and
and are not considered standard.
C173/C173M provide pressure, gravimetric, and volumetric
1.5 This standard does not purport to address all of the
procedures, respectively, for determining the air content of
safety concerns, if any, associated with its use. It is the
freshly mixed concrete. The pressure procedure of this test
responsibility of the user of this standard to establish appro-
method gives substantially the same air contents as the other
priate safety and health practices and determine the applica-
two test methods for concretes made with dense aggregates.
bility of regulatory limitations prior to use. (Warning—Fresh
3.3 The air content of hardened concrete may be either
hydraulic cementitious mixtures are caustic and may cause
2 higher or lower than that determined by this test method. This
chemical burns to skin and tissue upon prolonged exposure.)
depends upon the methods and amount of consolidation effort
2. Referenced Documents applied to the concrete from which the hardened concrete
3
specimenistaken;uniformityandstabilityoftheairbubblesin
2.1 ASTM Standards:
the fresh and hardened concrete; accuracy of the microscopic
examination, if used; time of comparison; environmental
1
This test method is under the jurisdiction of ASTM Committee C09 on
exposure; stage in the delivery, placement and consolidation
Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee
processes at which the air content of the unhardened concrete
C09.60 on Testing Fresh Concrete .
is determined, that is, before or after the concrete goes through
Current edition approved Oct. 1, 2008. Published November 2008. Originally
approved in 1949. Last previous edition approved in 2008 as C231–08b.
a pump; and other factors.
2
Section on Safety Precautions, Manual of Aggregate and Concrete Testing,
Annual Book of ASTM Standards, Vol 04.02.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
*A Summary of Changes section appears at the end of this standard.
Copyrigh
...

This document is not anASTM standard and is intended only to provide the user of anASTM 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:C231–08b Designation:C231–08c
Standard Test Method for
Air Content of Freshly Mixed Concrete by the Pressure
1
Method
This standard is issued under the fixed designation C231; 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 Department of Defense.
1. Scope*
1.1 Thistestmethodcoversdeterminationoftheaircontentoffreshlymixedconcretefromobservationofthechangeinvolume
of concrete with a change in pressure.
1.2 This test method is intended for use with concretes and mortars made with relatively dense aggregates for which the
aggregatecorrectionfactorcanbesatisfactorilydeterminedbythetechniquedescribedinSection6.Itisnotapplicabletoconcretes
made with lightweight aggregates, air-cooled blast-furnace slag, or aggregates of high porosity. In these cases, Test Method
C173/C173M should be used. This test method is also not applicable to nonplastic concrete such as is commonly used in the
manufacture of pipe and concrete masonry units.
1.3 The text of this test method references notes and footnotes that provide explanatory information.These notes and footnotes
(excluding those in tables and figures) shall not be considered as requirements of this standard.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and
2
tissue upon prolonged exposure.)
2. Referenced Documents
3
2.1 ASTM Standards:
C138/C138M Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
C172 Practice for Sampling Freshly Mixed Concrete
C173/C173M Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
C192/C192M Practice for Making and Curing Concrete Test Specimens in the Laboratory
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
3. Significance and Use
3.1 This test method covers the determination of the air content of freshly mixed concrete. The test determines the air content
offreshlymixedconcreteexclusiveofanyairthatmayexistinsidevoidswithinaggregateparticles.Forthisreason,itisapplicable
to concrete made with relatively dense aggregate particles and requires determination of the aggregate correction factor (see 6.1
and 9.1).
3.2 This test method and Test Method C138/C138M and C173/C173M provide pressure, gravimetric, and volumetric
procedures, respectively, for determining the air content of freshly mixed concrete. The pressure procedure of this test method
gives substantially the same air contents as the other two test methods for concretes made with dense aggregates.
3.3 The air content of hardened concrete may be either higher or lower than that determined by this test method. This depends
upon the methods and amount of consolidation effort applied to the concrete from which the hardened concrete specimen is taken;
uniformity and stability of the air bubbles in the fresh and hardened concrete; accuracy of the microscopic examination, if used;
1
This test method is under the jurisdiction ofASTM Committee C09 on Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee C09.60 on
Testing Fresh Concrete.
Current edition approved JuneOct. 1, 2008. Published JulyNovember 2008. Originally approved in 1949. Last previous edition approved in 2008 as C231–08ab.
2
Section on Safety Precautions, Manual of Aggregate and Concrete Testing, Annual Book of ASTM Standards, Vol 04.02.
3
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,[e-mail]ards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard.
Co
...