ASTM C31/C31M-21a

Standard Practice for Making and Curing Concrete Test Specimens in the Field

SIGNIFICANCE AND USE
4.1 This practice provides standardized requirements for making, curing, protecting, and transporting concrete test specimens under field conditions.  
4.2 If the specimens are made and standard cured, as stipulated herein, the resulting strength test data when the specimens are tested are able to be used for the following purposes:  
4.2.1 Acceptance testing for specified strength,  
4.2.2 Checking adequacy of mixture proportions for strength, and  
4.2.3 Quality control.  
4.3 If the specimens are made and field cured, as stipulated herein, the resulting strength test data when the specimens are tested are able to be used for the following purposes:  
4.3.1 Determination of whether a structure is capable of being put in service,  
4.3.2 Comparison with test results of standard cured specimens or with test results from various in-place test methods,  
4.3.3 Adequacy of curing and protection of concrete in the structure, or  
4.3.4 Form or shoring removal time requirements.
SCOPE
1.1 This practice covers procedures for making and curing cylinder and beam specimens from representative samples of fresh concrete for a construction project.  
1.2 The concrete used to make the molded specimens shall be sampled after all on-site adjustments have been made to the mixture proportions, including the addition of mix water and admixtures. This practice is not intended for making specimens from concrete not having measurable slump or requiring other sizes or shapes of specimens.  
1.3 This practice is not applicable to lightweight insulating concrete or controlled low strength material (CLSM).
Note 1: Test Method C495/C495M covers the preparation of specimens and the determination of the compressive strength of lightweight insulating concrete. Test Method D4832 covers procedures for the preparation, curing, transporting and testing of cylindrical test specimens of CLSM.  
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to exposed skin and tissue upon prolonged exposure.2)  
1.6 The text of this standard references notes which provide explanatory material. These notes shall not be considered as requirements of the standard.  
1.7 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: Historical
• Publication Date: 14-May-2021
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.61 - Testing for Strength

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: C31/C31M − 21a
Standard Practice for
1
Making and Curing Concrete Test Specimens in the Field
This standard is issued under the fixed designation C31/C31M; 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* 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice covers procedures for making and curing
ization established in the Decision on Principles for the
cylinder and beam specimens from representative samples of
Development of International Standards, Guides and Recom-
fresh concrete for a construction project.
mendations issued by the World Trade Organization Technical
1.2 The concrete used to make the molded specimens shall
Barriers to Trade (TBT) Committee.
be sampled after all on-site adjustments have been made to the
mixture proportions, including the addition of mix water and
2. Referenced Documents
admixtures.Thispracticeisnotintendedformakingspecimens
3
2.1 ASTM Standards:
from concrete not having measurable slump or requiring other
C125 Terminology Relating to Concrete and Concrete Ag-
sizes or shapes of specimens.
gregates
1.3 This practice is not applicable to lightweight insulating
C138/C138M Test Method for Density (Unit Weight),Yield,
concrete or controlled low strength material (CLSM).
and Air Content (Gravimetric) of Concrete
C143/C143M Test Method for Slump of Hydraulic-Cement
NOTE 1—Test Method C495/C495M covers the preparation of speci-
Concrete
mens and the determination of the compressive strength of lightweight
C172/C172M Practice for Sampling Freshly Mixed Con-
insulating concrete. Test Method D4832 covers procedures for the
preparation, curing, transporting and testing of cylindrical test specimens
crete
of CLSM.
C173/C173M Test Method forAir Content of Freshly Mixed
1.4 The values stated in either SI units or inch-pound units
Concrete by the Volumetric Method
are to be regarded separately as standard. The values stated in C231/C231M Test Method forAir Content of Freshly Mixed
each system may not be exact equivalents; therefore, each
Concrete by the Pressure Method
system shall be used independently of the other. Combining
C330/C330M Specification for Lightweight Aggregates for
values from the two systems may result in non-conformance
Structural Concrete
with the standard.
C403/C403M Test Method for Time of Setting of Concrete
Mixtures by Penetration Resistance
1.5 This standard does not purport to address all of the
C470/C470M Specification for Molds for Forming Concrete
safety concerns, if any, associated with its use. It is the
Test Cylinders Vertically
responsibility of the user of this standard to establish appro-
C495/C495M Test Method for Compressive Strength of
priate safety, health, and environmental practices and deter-
Lightweight Insulating Concrete
mine the applicability of regulatory limitations prior to use.
C511 Specification for Mixing Rooms, Moist Cabinets,
(Warning—Fresh hydraulic cementitious mixtures are caustic
Moist Rooms, and Water Storage Tanks Used in the
and may cause chemical burns to exposed skin and tissue upon
2
Testing of Hydraulic Cements and Concretes
prolonged exposure. )
C617/C617M Practice for Capping Cylindrical Concrete
1.6 The text of this standard references notes which provide
Specimens
explanatory material. These notes shall not be considered as
C1064/C1064M Test Method for Temperature of Freshly
requirements of the standard.
Mixed Hydraulic-Cement Concrete
C1077 Practice forAgencies Testing Concrete and Concrete
1
This practice is under the jurisdiction of ASTM Committee C09 on Concrete
Aggregates for Use in Construction and Criteria for
and Concrete Aggregates and is the direct responsibility of Subcommittee C09.61
on Testing for Strength.
Current edition approved May 15, 2021. Published May 2021. Originally
3
approved in 1920. Last previous edition approved in 2021 as C31/C31M–21. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/C0031_C0031M-21A. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
2
See Section on Safety Precautions, Manual ofAggregate and Concrete Testing, Standards volume information, refer to the standard’s Document Summary page on
Annual Book of ASTM Standards, Vol. 04.02. 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 Stat
...

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: C31/C31M − 21 C31/C31M − 21a
Standard Practice for
1
Making and Curing Concrete Test Specimens in the Field
This standard is issued under the fixed designation C31/C31M; 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 practice covers procedures for making and curing cylinder and beam specimens from representative samples of fresh
concrete for a construction project.
1.2 The concrete used to make the molded specimens shall be sampled after all on-site adjustments have been made to the mixture
proportions, including the addition of mix water and admixtures. This practice is not intended for making specimens from concrete
not having measurable slump or requiring other sizes or shapes of specimens.
1.3 This practice is not applicable to lightweight insulating concrete or controlled low strength material (CLSM).
NOTE 1—Test Method C495/C495M covers the preparation of specimens and the determination of the compressive strength of lightweight insulating
concrete. Test Method D4832 covers procedures for the preparation, curing, transporting and testing of cylindrical test specimens of CLSM.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns
2
to exposed skin and tissue upon prolonged exposure. )
1.6 The text of this standard references notes which provide explanatory material. These notes shall not be considered as
requirements of the standard.
1.7 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.
1
This practice is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.61 on Testing
for Strength.
Current edition approved March 1, 2021May 15, 2021. Published March 2021May 2021. Originally approved in 1920. Last previous edition approved in 2019a2021 as
C31/C31M–19.–21. DOI: 10.1520/C0031_C0031M-21.10.1520/C0031_C0031M-21A.
2
See Section on Safety Precautions, Manual of Aggregate and Concrete Testing, Annual Book of ASTM Standards, Vol. 04.02.
*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
1

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C31/C31M − 21a
2. Referenced Documents
3
2.1 ASTM Standards:
C125 Terminology Relating to Concrete and Concrete Aggregates
C138/C138M Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
C143/C143M Test Method for Slump of Hydraulic-Cement Concrete
C172/C172M Practice for Sampling Freshly Mixed Concrete
C173/C173M Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
C231/C231M Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
C330/C330M Specification for Lightweight Aggregates for Structural Concrete
C403/C403M Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance
C470/C470M Specification for Molds for Forming Concrete Test Cylinders Vertically
C495/C495M Test Method for Compressive Strength of Lightweight Insulating Concrete
C511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic
Cements and Concretes
C617/C617M Practice for Capping Cylindrical Concrete Specimens
C1064/C1064M Tes
...