ASTM C172-99
(Practice)Standard Practice for Sampling Freshly Mixed Concrete
Standard Practice for Sampling Freshly Mixed Concrete
SCOPE
1.1 This practice covers procedures for obtaining representative samples of fresh concrete as delivered to the project site on which tests are to be performed to determine compliance with quality requirements of the specifications under which the concrete is furnished (Note 1). The practice includes sampling from stationary, paving and truck mixers, and from agitating and nonagitating equipment used to transport central-mixed concrete.
1.2 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate. Note 1-Composite samples are required by this practice, unless specifically excepted by procedures governing the tests to be performed such as tests to determine uniformity of consistency and mixer efficiency. Procedures used to select the specific test batches are not described in this practice, but it is recommended that random sampling be used to determine over-all specification compliance.
1.3 This practice also covers the procedures to be used for preparing a sample of concrete for further testing where it is desirable or necessary to remove the aggregate larger than a designated size. This removal of larger aggregate particles is preferably accomplished by wet-sieving.
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Designation: C 172 – 99
Standard Practice for
Sampling Freshly Mixed Concrete
This standard is issued under the fixed designation C 172; 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 (e) 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 3. Significance and Use
1.1 This practice covers procedures for obtaining represen- 3.1 This practice is intended to provide standard require-
tative samples of fresh concrete as delivered to the project site ments and procedures for sampling freshly mixed concrete
on which tests are to be performed to determine compliance from different containers used in the production or transporta-
with quality requirements of the specifications under which the tion of concrete. The detailed requirements as to materials,
concrete is furnished (Note 1). The practice includes sampling mixtures, air content, temperature, number of specimens,
from stationary, paving and truck mixers, and from agitating slump, interpretation of results, and precision and bias are in
and nonagitating equipment used to transport central-mixed specific test methods.
concrete.
4. Sampling
1.2 The values stated in SI units are to be regarded as the
4.1 The elapsed time shall not exceed 15 min. between
standard. The values shown in parentheses are provided for
information only. obtaining the first and final portions of the composite sample.
4.1.1 Transport the individual samples to the place where
NOTE 1—Composite samples are required by this practice, unless
fresh concrete tests are to be performed or where test speci-
specifically excepted by procedures governing the tests to be performed
mens are to be molded. They shall be combined and remixed
such as tests to determine uniformity of consistency and mixer efficiency.
with a shovel the minimum amount necessary to ensure
Procedures used to select the specific test batches are not described in this
practice, but it is recommended that random sampling be used to uniformity and compliance with the maximum time limits
determine over-all specification compliance.
specified in 4.1.2.
4.1.2 Start tests for slump, temperature, and air content
1.3 This practice also covers the procedures to be used for
within 5 min after obtaining the final portion of the composite
preparing a sample of concrete for further testing where it is
sample. Complete these tests expeditiously. Start molding
desirable or necessary to remove the aggregate larger than a
specimens for strength tests within 15 min after fabricating the
designated size. This removal of larger aggregate particles is
composite sample. Expeditiously obtain and use the sample
preferably accomplished by wet-sieving.
and protect the sample from the sun, wind, and other sources of
1.4 The text of this standard references notes and footnotes
rapid evaporation, and from contamination.
which provide explanatory material and shall not be considered
as requirements of the practice.
5. Procedure
1.5 This standard does not purport to address all of the
5.1 Size of Sample—Make the samples to be used for
safety concerns, if any, associated with its use. It is the
strength tests a minimum of 28 L (1 ft ). Smaller samples are
responsibility of the user of this standard to establish appro-
not prohibited for routine air content, temperature, and slump
priate safety and health practices and determine the applica-
tests. The size of the samples shall be dictated by the maximum
bility of regulatory limitations prior to use.
aggregate size.
2. Referenced Documents
5.2 The procedures used in sampling shall include the use of
every precaution that will assist in obtaining samples that are
2.1 ASTM Standards:
truly representative of the nature and condition of concrete
E 11 Specification for Wire-Cloth and Sieves for Testing
sampled as follows:
Purposes
NOTE 2—Sampling should normally be performed as the concrete is
delivered from the mixer to the conveying vehicle used to transport the
This practice is under the jurisdiction of ASTM Committee C-9 on Concrete
concrete to the forms; however, specifications may require other points of
and Concrete Aggregatesand is the direct responsibility of Subcommittee C09.60 on
sampling, such as the discharge of a concrete pump.
Fresh Concrete Testing.
Current edition approved Sept. 10, 1999. Published October 1999. Originally
published as C 172 – 42. Last previous edition C 172 – 97.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 172
5.2.1 Sampling from Stationary Mixers, Except Paving 6. Additional Procedure for Large Maximum Size
Mixers—Sample the concrete by collecting two or more Aggregate Concrete
portions taken at regularly spaced intervals during discharge of
6.1 When the concrete contains aggregate larger than that
the middle portion of the batch. Obtain these portions within
appropriate for the size of the molds or equipment to be used,
the time limit specified in Section 4. Composite the portions
wet-sieve the sample as described below except make unit-
into one sample for testing purposes. Do not obtain portions of
weight tests for use in yield computations on the full mix.
the composite sample from the very first or last part of the
batch discharge (Note 3). Perform sampling by passing a
NOTE 5—The effect of wet-sieving on the test results should be
receptacle completely through the discharge stream, or by
considered. For example, wet-sieving concrete causes the loss of a small
amount of air due to additional handling. The air content of the wet-sieved
completely diverting the discharge into a sample container. If
fraction of concrete is greater than that of the total concrete because the
discharge of the conc
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