ASTM C642-21

Standard Test Method for Density, Absorption, and Voids in Hardened Concrete

SIGNIFICANCE AND USE
4.1 This test method is useful in developing the data required for conversions between mass and volume for concrete. It can be used to determine conformance with specifications for concrete and to show differences from place to place within a mass of concrete.
SCOPE
1.1 This test method covers the determinations of density, percent absorption, and percent voids in hardened concrete.  
1.2 The text of this test method references notes and footnotes which provide explanatory information. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard.  
1.3 The values stated in SI units are to be regarded as the standard.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 14-Dec-2021
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.66 - Concrete's Resistance to Fluid Penetration

Relations

• Refers: ASTM C125-19a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2019
• Refers: ASTM C125-19 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jan-2019
• Refers: ASTM C125-18b - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Oct-2018
• Refers: ASTM C125-18a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jul-2018
• Refers: ASTM C125-18 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jan-2018
• Refers: ASTM C125-16 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2016
• Refers: ASTM C125-15b - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2015
• Refers: ASTM C125-15a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jul-2015
• Refers: ASTM C125-15 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Feb-2015
• Refers: ASTM C125-14 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Aug-2014
• Refers: ASTM C125-13b - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2013
• Refers: ASTM C125-13a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Aug-2013
• Refers: ASTM C125-13 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Feb-2013
• Refers: ASTM C125-12a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Dec-2012
• Refers: ASTM C125-12 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Aug-2012

Overview

ASTM C642-21 is the internationally recognized standard test method developed by ASTM International for determining the density, absorption, and voids in hardened concrete. This test method provides essential data for understanding the physical characteristics of concrete, including its mass-to-volume relationships and internal structure. Organizations and professionals in the construction, civil engineering, and materials science fields rely on this standard to ensure quality, consistency, and specification compliance for concrete used in a diverse array of projects.

Key Topics

• Density Measurement: The standard outlines procedures for testing the bulk and apparent density of hardened concrete samples, helping assess material quality and predicting structural performance.
• Water Absorption: ASTM C642-21 defines methods for measuring the percentage of water absorbed by concrete under immersion and after boiling, offering insight into concrete durability and porosity.
• Voids Calculation: By measuring permeable and impermeable void content, this standard supports the assessment of concrete's resistance to fluid penetration and freeze-thaw cycles.
• Specimen Preparation: Guidance on sample selection, conditioning, and preparation ensures consistency and accuracy across test results.
• Test Apparatus and Procedure: Specifies equipment requirements and step-by-step testing protocols, emphasizing reproducibility and adherence to safety guidelines.

Applications

ASTM C642-21 is widely used in a variety of practical applications across the concrete industry:

• Quality Control: Helps producers, contractors, and inspectors verify that concrete meets specified density, absorption, and void limits, ensuring consistent performance across different batches and locations within a structure.
• Specification Compliance: Essential for demonstrating that hardened concrete satisfies project or regulatory requirements regarding porosity, water absorption, and overall durability.
• Research and Development: Supports the development of new concrete mixtures, enabling researchers to compare the effects of additives, aggregates, and curing processes on concrete properties.
• Assessment of Structural Performance: Concrete’s density and void structure directly impact mechanical strength, resistance to weathering, and impermeability to fluids - all critical factors for structural safety and longevity.
• Forensic Analysis: Used in analyzing concrete from existing structures to determine causes of deterioration, water ingress, or other service-life issues.

Related Standards

Several other ASTM standards provide complementary methods and definitions relevant to density, absorption, and void analysis in concrete:

• ASTM C125 – Terminology Relating to Concrete and Concrete Aggregates
  Provides key definitions used in ASTM C642-21 and other ASTM concrete standards.
• ASTM C31/C31M – Standard Practice for Making and Curing Concrete Test Specimens in the Field
  Addresses specimen preparation, which can impact results using C642-21.
• ASTM C39/C39M – Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
  Often used in conjunction with C642-21 when assessing structural concrete.
• ASTM C1202 – Standard Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration
  Related to evaluating permeability and durability.

By using ASTM C642-21, professionals can reliably evaluate and interpret key characteristics of hardened concrete, leading to more durable, resilient, and long-lasting concrete structures. For consistent and high-quality results, always reference the latest official version of the standard and comply with all safety and regulatory requirements.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C642 − 21
Standard Test Method for
Density, Absorption, and Voids in Hardened Concrete
This standard is issued under the fixed designation C642; 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.
1. Scope* crete. It can be used to determine conformance with specifica-
tions for concrete and to show differences from place to place
1.1 This test method covers the determinations of density,
within a mass of concrete.
percent absorption, and percent voids in hardened concrete.
1.2 The text of this test method references notes and
5. Apparatus
footnotes which provide explanatory information. These notes
5.1 Balance, sensitive to 0.025 % of the mass of the
and footnotes (excluding those in tables and figures) shall not
specimen.
be considered as requirements of this standard.
5.2 Container, suitable for immersing the specimen and
1.3 The values stated in SI units are to be regarded as the
suitable wire for suspending the specimen in water.
standard.
1.4 This standard does not purport to address all of the
6. Test Specimen
safety concerns, if any, associated with its use. It is the
6.1 Whenever possible, the sample shall consist of several
responsibility of the user of this standard to establish appro-
individual portions of concrete, each to be tested separately.
priate safety, health, and environmental practices and deter-
The individual portions may be pieces of cylinders, cores, or
mine the applicability of regulatory limitations prior to use.
beams of any desired shape or size, except that the volume of
1.5 This international standard was developed in accor-
each portion shall be not less than 350 cm (or for normal
dance with internationally recognized principles on standard-
weight concrete, approximately 800 g); and each portion shall
ization established in the Decision on Principles for the
be free from observable cracks, fissures, or shattered edges.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
7. Procedure
Barriers to Trade (TBT) Committee.
7.1 Oven-Dry Mass—Determine the mass of the portions,
and dry in an oven at a temperature of 110°C 6 5°C for not
2. Referenced Documents
less than 24 h. After removing each specimen from the oven,
2.1 ASTM Standards:
allow it to cool in dry air (preferably in a desiccator) to a
C125Terminology Relating to Concrete and Concrete Ag-
temperature of 20°C to 25°C and determine the mass. If the
gregates
specimen was comparatively dry when its mass was first
determined, and the second mass closely agrees with the first,
3. Terminology
consideritdry.Ifthespecimenwaswetwhenitsmasswasfirst
3.1 For definitions of terms used in this standard, refer to
determined, place it in the oven for a second drying treatment
Terminology C125.
of 24 h and again determine the mass. If the third value checks
the second, consider the specimen dry. In case of any doubt,
4. Significance and Use
redry the specimen for 24h periods until check values of mass
4.1 This test method is useful in developing the data
are obtained. If the difference between values obtained from
required for conversions between mass and volume for con-
two successive values of mass exceeds 0.5% of the lesser
value, return the specimens to the oven for an additional 24h
drying period, and repeat the procedure until the difference
This test method is under the jurisdiction of ASTM Committee C09 on
between any two successive values is less than 0.5% of the
Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee
C09.66 on Concrete’s Resistance to Fluid Penetration.
lowest value obtained. Designate this last value A.
Current edition approved Dec. 15, 2021. Published January 2022. Originally
7.2 Saturated Mass After Immersion—Immerse the
approved in 1969. Last previous edition approved in 2013 as C642–13. DOI:
10.1520/C0642-21.
specimen, after final drying, cooling, and determination of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
mass,inwateratapproximately21°Cfornotlessthan48hand
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
untiltwosuccessivevaluesofmassofthesurface-driedsample
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. atintervalsof24hshowanincreaseinmassoflessthan0.5%
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C642 − 21
of the larger value. Surface-dry the specimen by removing 9.5 Based on the assumptions given in 9.1 – 9.4 above, the
surface moisture with a towel, and determine the mass. data that would be developed from the procedures given in
Designate the final surface-dry mass after immersion B.
Section 7 would be as follows:
9.5.1 Oven-dry mass, A=1000 g.
7.3 Saturated Mass After Boiling—Place the specimen,
processed as described in 7.2, in a suitable receptacle, covered
9.5.2 Mass in air after immersion, B=1090 g.
withtapwater,andboilfor5h.Allowittocoolbynaturalloss
9.5.3 Mass in air after immersion and boiling, C=1095 g.
of heat for not less than 14 h to a final temperature of 20°C to
9.5.4 Apparent mass in water after immersion and boiling,
25°C. Remove the surface moisture with a towel and deter-
D=495 g.
mine the mass of the specimen. Designate the soaked, boiled,
surface-dried mass C.
NOTE 1—Since loss of mass in water is equal to mass of displaced
water, and volume of specimen=600 cm , mass of specimen in water
7.4 Immersed Apparent Mass—Suspend the specimen, after
after immersion and boiling is 1095−600=495 g.
immersion and boiling, by a wire and determine the apparent
mass in water. Designate this apparent mass D. 9.6 By using
...

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: C642 − 13 C642 − 21
Standard Test Method for
Density, Absorption, and Voids in Hardened Concrete
This standard is issued under the fixed designation C642; 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.
1. Scope*
1.1 This test method covers the determinations of density, percent absorption, and percent voids in hardened concrete.
1.2 The text of this test method references notes and footnotes which provide explanatory information. These notes and footnotes
(excluding those in tables and figures) shall not be considered as requirements of this standard.
1.3 The values stated in SI units are to be regarded as the standard.
1.4 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.
1.4 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C125 Terminology Relating to Concrete and Concrete Aggregates
3. Terminology
3.1 For definitions of terms used in this standard, refer to Terminology C125.
4. Significance and Use
4.1 This test method is useful in developing the data required for conversions between mass and volume for concrete. It can be
used to determine conformance with specifications for concrete and to show differences from place to place within a mass of
concrete.
This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.66 on
Concrete’s Resistance to Fluid Penetration.
Current edition approved Feb. 1, 2013Dec. 15, 2021. Published February 2013January 2022. Originally approved in 1969. Last previous edition approved in 20062013
as C642 – 06.C642 – 13. DOI: 10.1520/C0642-13.10.1520/C0642-21.
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
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C642 − 21
5. Apparatus
5.1 Balance, sensitive to 0.025 % of the mass of the specimen.
5.2 Container, suitable for immersing the specimen and suitable wire for suspending the specimen in water.
6. Test Specimen
6.1 Whenever possible, the sample shall consist of several individual portions of concrete, each to be tested separately. The
individual portions may be pieces of cylinders, cores, or beams of any desired shape or size, except that the volume of each portion
shall be not less than 350 cm (or for normal weight concrete, approximately 800 g); and each portion shall be free from observable
cracks, fissures, or shattered edges.
7. Procedure
7.1 Oven-Dry Mass—Determine the mass of the portions, and dry in an oven at a temperature of 110110 °C 6 5°C5 °C for not
less than 24 h. After removing each specimen from the oven, allow it to cool in dry air (preferably in a desiccator) to a temperature
of 2020 °C to 25°C25 °C and determine the mass. If the specimen was comparatively dry when its mass was first determined, and
the second mass closely agrees with the first, consider it dry. If the specimen was wet when its mass was first determined, place
it in the oven for a second drying treatment of 24 h and again determine the mass. If the third value checks the second, consider
the specimen dry. In case of any doubt, redry the specimen for 24-h24 h periods until check values of mass are obtained. If the
difference between values obtained from two successive values of mass exceeds 0.5 % of the lesser value, return the specimens
to the oven for an additional 24-h24 h drying period, and repeat the procedure until the difference between any two successive
values is less than 0.5 % of the lowest value obtained. Designate this last value A.
7.2 Saturated Mass After Immersion—Immerse the specimen, after final drying, cooling, and determination of mass, in water at
approximately 21°C for not less than 48 h and until two successive values of mass of the surface-dried sample at intervals of 24
h show an increase in mass of less than 0.5 % of the larger value. Surface-dry the specimen by removing surface moisture with
a towel, and determine the mass. Designate the final surface-dry mass after immersion B.
7.3 Saturated Mass After Boiling—Place the specimen, processed as described in 5.27.2, in a suitable receptacle, covered with tap
water, and boil for 5 h. Allow it to cool by natural loss of heat for not less than 14 h to a final temperature of 2020 °C to 25°C.25 °C.
Remove the surface moisture with a towel and determine the mass of the specimen. Designate the soaked, boiled, surface-dried
mass C.
7.4 Immersed Apparent Mass—Suspend the specimen, after immersion and boiling, by a wire and determine the apparent mass
in water. Designate this apparent mass D.
8. Calculation
8.1 By using the values for mass determined in accordance with the procedures described in Section 57, make the following
calculations:
Absorption after immersion, %5 B 2 A /A 3100 (1)
@~ ! #
Absorption after immersion and boiling, %5 @~C 2 A!/A# 3100 (2)
Bulk density, dry 5 @A/~C 2 D!#·ρ5 g (3)
Bulk density after immersion 5 B/ C 2 D ·ρ (4)
@ ~ !#
Bulk density after immersion and boiling 5 C/ C
...