ASTM C192/C192M-19

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

SIGNIFICANCE AND USE
4.1 This practice provides standardized requirements for preparation of materials, mixing concrete, and making and curing concrete test specimens under laboratory conditions.  
4.2 If specimen preparation is controlled as stipulated herein, the specimens may be used to develop information for the following purposes:  
4.2.1 Mixture proportioning for project concrete,  
4.2.2 Evaluation of different mixtures and materials,  
4.2.3 Correlation with nondestructive tests, and  
4.2.4 Providing specimens for research purposes.  
Note 1: The concrete test results for concrete specimens made and cured using this practice are widely used. They may be the basis for acceptance testing for project concrete, research evaluations, and other studies. Careful and knowledgeable handling of materials, mixing concrete, molding test specimens, and curing test specimens is necessary. Many laboratories performing this important work are independently inspected or accredited. Practice C1077 identifies and defines the duties, responsibilities, and minimum technical qualification requirements of laboratory personnel and the minimum requirements for equipment used in testing concrete and concrete aggregates.
SCOPE
1.1 This practice covers procedures for making and curing test specimens of concrete in the laboratory under accurate control of materials and test conditions using concrete that can be consolidated by rodding or vibration as described herein.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.3 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)  
1.4 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: 30-Nov-2019
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.61 - Testing for Strength

Relations

• Refers: ASTM C31/C31M-24a - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Apr-2024
• Refers: ASTM C31/C31M-24 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Jan-2024
• Refers: ASTM C173/C173M-24 - Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
• Effective Date: 01-Jan-2024
• Refers: ASTM C231/C231M-24 - Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
• Effective Date: 01-Jan-2024
• Refers: ASTM C1077-24 - Standard Practice for Agencies Testing Concrete and Concrete Aggregates for Use in Construction and Criteria for Testing Agency Evaluation
• Effective Date: 01-Jan-2024
• Refers: ASTM C1064/C1064M-23 - Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete
• Effective Date: 01-Dec-2023
• Refers: ASTM C1758/C1758M-23 - Standard Practice for Fabricating Test Specimens with Self-Consolidating Concrete
• Effective Date: 01-Oct-2023
• Refers: ASTM C617/C617M-23 - Standard Practice for Capping Cylindrical Concrete Specimens
• Effective Date: 01-Oct-2023
• Refers: ASTM C173/C173M-23 - Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
• Effective Date: 01-Sep-2023
• Refers: ASTM C70-20 - Standard Test Method for Surface Moisture in Fine Aggregate
• Effective Date: 01-Feb-2020
• 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 C31/C31M-18 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Jan-2018

Overview

ASTM C192/C192M-19: Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory is an international standard developed by ASTM. This practice provides systematic procedures for the preparation of materials, mixing, and curing of concrete test specimens under well-controlled laboratory conditions. Adherence to this standard ensures that concrete specimens are prepared in a consistent, reliable manner, enabling the accurate evaluation of concrete properties and performance.

The standard is essential for laboratories and professionals involved in concrete research, quality control, and acceptance testing. It covers all aspects of specimen creation-from material handling and batching to mixing, molding, consolidation, and curing.

Key Topics

• Specimen Preparation
  The practice outlines strict protocols for preparing concrete materials, including temperature conditioning and moisture control of aggregates and cement. Admixtures must be added properly as per the guidelines to ensure repeatable results.

• Mixing Procedures
  Procedures for both hand-mixing (small batches) and machine-mixing (larger batches) are described, emphasizing consistent mixing sequence, timing, and prevention of batch-to-batch variation.

• Molding and Consolidation
  Techniques for placing freshly-mixed concrete into molds, including proper layering and use of tamping rods and vibrators. The standard specifies how specimens should be layered, consolidated, and struck off to ensure uniform density and minimal air entrapment.

• Curing Requirements
  Curing of the specimens is to be performed under controlled laboratory conditions to ensure representative strength development and durability performance.

• Specimen Types and Sizes
  The document clarifies dimensions and configurations for cylinders, beams, and prisms as required by related testing standards, and recommends suitable specimen sizes relative to aggregate size.

• Safety Considerations
  Users are reminded of the caustic nature of fresh cementitious mixtures and the need for adequate safety and health practices during the preparation of test specimens.

Applications

The procedures defined in ASTM C192/C192M-19 are crucial for:

• Mixture Proportioning and Optimization
  Developing the optimal design mix for specific construction projects by comparing the performance of different concrete mixtures under standardized laboratory conditions.

• Materials Evaluation
  Assessing new types or sources of cement, aggregates, admixtures, or reinforcement, and their influence on concrete performance.

• Acceptance Testing
  Generating compressive and flexural strength data for use in project acceptance and specification compliance.

• Correlation with Nondestructive Testing
  Creating reference specimens with known properties for calibrating non-destructive testing techniques.

• Research and Development
  Supplying standardized concrete specimens for innovative research, durability studies, or fundamental material investigations.

Related Standards

Understanding and proper use of ASTM C192/C192M-19 is enhanced by reference to associated standards, including but not limited to:

• ASTM C31/C31M - Practice for Making and Curing Concrete Test Specimens in the Field
• ASTM C125 - Terminology Relating to Concrete and Concrete Aggregates
• ASTM C138/C138M - Test Method for Density (Unit Weight), Yield, and Air Content of Concrete
• ASTM C143/C143M - Test Method for Slump of Hydraulic-Cement Concrete
• ASTM C511 - Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks
• ASTM C617/C617M - Practice for Capping Cylindrical Concrete Specimens
• ASTM C1077 - Practice for Agencies Testing Concrete and Concrete Aggregates

By following ASTM C192/C192M-19 and related standards, testing laboratories enhance the accuracy, reliability, and comparability of concrete test results, thereby supporting quality assurance and innovation in the construction industry.

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: C192/C192M − 19
Standard Practice for
Making and Curing Concrete Test Specimens in the
Laboratory
This standard is issued under the fixed designation C192/C192M; 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* Specimens in the Field
C70 Test Method for Surface Moisture in Fine Aggregate
1.1 This practice covers procedures for making and curing
C125 Terminology Relating to Concrete and Concrete Ag-
test specimens of concrete in the laboratory under accurate
gregates
control of materials and test conditions using concrete that can
C127 Test Method for Relative Density (Specific Gravity)
be consolidated by rodding or vibration as described herein.
and Absorption of Coarse Aggregate
1.2 The values stated in either SI units or inch-pound units
C128 Test Method for Relative Density (Specific Gravity)
are to be regarded separately as standard. The values stated in
and Absorption of Fine Aggregate
each system are not necessarily exact equivalents; therefore, to
C138/C138M Test Method for Density (Unit Weight),Yield,
ensure conformance with the standard, each system shall be
and Air Content (Gravimetric) of Concrete
used independently of the other, and values from the two
C143/C143M Test Method for Slump of Hydraulic-Cement
systems shall not be combined.
Concrete
1.3 This standard does not purport to address all of the
C172/C172M Practice for Sampling Freshly Mixed Con-
safety concerns, if any, associated with its use. It is the
crete
responsibility of the user of this standard to establish appro-
C173/C173M Test Method forAir Content of Freshly Mixed
priate safety, health, and environmental practices and deter-
Concrete by the Volumetric Method
mine the applicability of regulatory limitations prior to use.
C231/C231M Test Method forAir Content of Freshly Mixed
(Warning—Fresh hydraulic cementitious mixtures are caustic
Concrete by the Pressure Method
and may cause chemical burns to exposed skin and tissue upon
C330/C330M Specification for Lightweight Aggregates for
prolonged exposure. )
Structural Concrete
1.4 This international standard was developed in accor-
C403/C403M Test Method for Time of Setting of Concrete
dance with internationally recognized principles on standard-
Mixtures by Penetration Resistance
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- C470/C470M Specification for Molds for Forming Concrete
mendations issued by the World Trade Organization Technical Test Cylinders Vertically
Barriers to Trade (TBT) Committee.
C494/C494M Specification for Chemical Admixtures for
Concrete
2. Referenced Documents
C511 Specification for Mixing Rooms, Moist Cabinets,
2.1 ASTM Standards: Moist Rooms, and Water Storage Tanks Used in the
C31/C31M Practice for Making and Curing Concrete Test Testing of Hydraulic Cements and Concretes
C566 Test Method forTotal Evaporable Moisture Content of
Aggregate by Drying
This practice is under the jurisdiction of ASTM Committee C09 on Concrete
C617/C617M Practice for Capping Cylindrical Concrete
andConcreteAggregatesandisthedirectresponsibilityofSubcommitteeC09.61on
Specimens
Testing for Strength.
Current edition approved Dec. 1, 2019. Published February 2020. Originally
C1064/C1064M Test Method for Temperature of Freshly
approved in 1944. Last previous edition approved in 2018 as C192/C192M – 18.
Mixed Hydraulic-Cement Concrete
DOI: 10.1520/C0192_C0192M-19.
2 C1077 Practice forAgencies Testing Concrete and Concrete
See section on Safety Precautions, Manual ofAggregate and Concrete Testing,
Annual Book of ASTM Standards, Vol 04.02.
Aggregates for Use in Construction and Criteria for
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Testing Agency Evaluation
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
C1611/C1611M Test Method for Slump Flow of Self-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Consolidating Concrete
*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
C192/C192M − 19
C1758/C1758M Practice for Fabricating Test Specimens 5.2.2 Horizontal Molds for Creep Test Cylinders shall
with Self-Consolidating Concrete conform to the requirements of 5.1 and to the requirements for
symmetry and dimensional tolerance in the section on General
2.2 American Concrete Institute Publications:
Requirements except for verticality requirements of Specifica-
211.3 Practice for Selecting Proportions for No-Slump Con-
tion C470/C470M. The use of horizontal molds is intended
crete
only for creep specimens that contain axially embedded strain
309R Guide for Consolidation of Concrete
gages. Molds for creep cylinders to be filled while supported in
a horizontal position shall have a filling slot parallel to the axis
3. Terminology
of the mold which extends the full length to receive the
3.1 For definitions of terms used in this practice, refer to
concrete.The width of the slot shall be one half the diameter of
Terminology C125.
the specimen. If necessary the edges of the slot shall be
reinforced to maintain dimensional stability. Unless specimens
4. Significance and Use
are to be capped or ground to produce plane ends, the molds
4.1 This practice provides standardized requirements for
shall be provided with two machined metal end plates at least
preparation of materials, mixing concrete, and making and 25mm[1in.]thickandtheworkingsurfacesshallcomplywith
curing concrete test specimens under laboratory conditions. the requirements for planeness and surface roughness given in
the section on Capping Plates of Practice C617/C617M.
4.2 If specimen preparation is controlled as stipulated
Provision shall be made for fixing both end plates firmly to the
herein, the specimens may be used to develop information for
mold. The inside surface of each end plate shall be provided
the following purposes:
with at least three lugs or studs approximately 25 mm [1 in.]
4.2.1 Mixture proportioning for project concrete,
long, firmly fastened to the plate for embedment in the
4.2.2 Evaluation of different mixtures and materials,
concrete. One base plate shall be drilled from the inside at an
4.2.3 Correlation with nondestructive tests, and
angle to permit the lead wire from the strain gage to exit the
4.2.4 Providing specimens for research purposes.
specimen through the edge of the plate. Provision shall be
NOTE 1—The concrete test results for concrete specimens made and
made for accurately positioning the strain gage. All necessary
cured using this practice are widely used. They may be the basis for
holes shall be as small as possible to minimize disturbance to
acceptance testing for project concrete, research evaluations, and other
subsequent strain measurements and shall be sealed to prevent
studies. Careful and knowledgeable handling of materials, mixing
leakage.
concrete, molding test specimens, and curing test specimens is necessary.
Many laboratories performing this important work are independently
5.3 Beam and Prism Molds shall be rectangular in shape
inspected or accredited. Practice C1077 identifies and defines the duties,
(unless otherwise specified) and of the dimensions required to
responsibilities, and minimum technical qualification requirements of
laboratory personnel and the minimum requirements for equipment used produce the desired specimen size. The inside surfaces of the
in testing concrete and concrete aggregates.
molds shall be smooth and free from indentations. The sides,
bottom, and ends shall be at right angles to each other and shall
5. Apparatus
be straight and true and free of warpage. Maximum variation
from the nominal cross section shall not exceed 3 mm [ ⁄8 in.]
5.1 Molds, General—Molds for specimens or fastenings
for molds with depth or breadth of 150 mm [6 in.] or more, or
thereto in contact with the concrete shall be made of steel, cast
2mm[ ⁄16 in.] for molds of smaller depth or breadth. Except
iron, or other nonabsorbent material, nonreactive with concrete
for flexure specimens, molds shall not vary from the nominal
containing portland or other hydraulic cements. Molds shall
length by more than 2 mm [ ⁄16 in.]. Flexure molds shall not be
conform to the dimensions and tolerances specified in the
shorter than 2 mm [ ⁄16 in.] of the required length, but may
method for which the specimens are required. Molds shall hold
exceed it by more than that amount.
their dimensions and shape under all conditions of use.
Watertightness of molds during use shall be judged by their
5.4 Tamping Rod—Around, smooth, straight, steel rod with
ability to hold water poured into them. Test procedures for
watertightness are given in the section on Test Methods for
Elongation, Absorption, and Watertightness of Specification
TABLE 1 Number of Layers Required for Specimens
C470/C470M. A suitable sealant, such as heavy grease, mod-
Specimen Type and Size Mode of Numbers of Layers
eling clay, or microcrystalline wax, shall be used where Consolidation of Approximate
Equal Depth
necessary to prevent leakage through the joints. Positive means
Cylinders:
shall be provided to hold base plates firmly to the molds.
Diameter, mm [in.]
Reusable molds shall be lightly coated with mineral oil or a
75 to 100 [3 or 4] rodding 2
150 [6] rodding 3
suitable nonreactive release material before use.
225 [9] rodding 4
5.2 Cylinder Molds: up to 225 [9] vibration 2
5.2.1 Molds for Casting Specimens Vertically shall conform
Prisms and horizontal creep Cylinders:
to the requirements of 5.1 and Specification C470/C470M.
Depth, mm [in.]
up to 200 [8] rodding 2
over 200 [8] rodding 3 or more
up to 200 [8] vibration 1
Available fromAmerican Concrete Institute (ACI), P.O. Box 9094, Farmington over 200 [8] vibration 2 or more
Hills, MI 48333-9094, http://www.aci-int.org.
C192/C192M − 19
a diameter conforming to the requirements in Table 2. The 5.8 Slump and Slump Flow Apparatus—The apparatus for
length of the tamping rod shall be at least 100 mm [4 in.] measurement of slump or slump flow shall conform to the
greater than the depth of the mold in which rodding is being requirements of Test Method C143/C143M or Test Method
performed, but not greater than 600 mm [24 in.] in overall C1611/C1611M, respectively.
length (see Note 2).The rod shall have the tamping end or both
5.9 SamplingandMixingPan—Thepanshallbeflat-bottom
endsroundedtoahemisphericaltipofthesamediameterasthe
and of heavy-gage metal, watertight, of convenient depth, and
rod.
of sufficient capacity to allow easy mixing by shovel or trowel
of the entire batch; or, if mixing is by machine, to receive the
NOTE 2—Arod length of 400 mm [16 in.] to 600 mm [24 in.] meets the
requirements of the following: Practice C31/C31M, Test Method C138/
entire batch on discharge of the mixer and allow remixing in
C138M, Test Method C143/C143M, Test Method C173/C173M, and Test
the pan by trowel or shovel.
Method C231/C231M.
5.10 Wet-SievingEquipment—If wet-sieving is required, the
5.5 Mallets—Amallet with a rubber or rawhide head weigh-
equipment shall conform to the requirements of Practice
ing 0.6 6 0.2 kg [1.25 6 0.50 lb] shall be used.
C172/C172M.
5.6 Vibrators:
5.11 Air Content Apparatus—The apparatus for measuring
5.6.1 Internal Vibrators—The vibrator frequency shall be at
air content shall conform to the requirements of either Test
least 9000 vibrations per minute [150 Hz] while the vibrator is
Methods C231/C231M or C173/C173M.
operating in the concrete. The diameter of a round vibrator
shall be no more than one fourth the diameter of the cylinder 5.12 Scales—Scales for determining the mass of batches of
mold or one fourth the width of the beam or prism mold. Other materialsandconcreteshallbeaccuratewithin0.3 %ofthetest
shaped vibrators shall have a perimeter equivalent to the load at any point within the range of use.
circumference of an appropriate round vibrator. The combined
NOTE 5—In general the mass of small quantities should not be
length of the vibrator shaft and vibrating element shall exceed
determined on large capacity scales. In many applications the smallest
the depth of the section being vibrated by at least 75 mm [3
mass determined on a scale should be greater than about 10 % of the
in.]. The vibrator frequency shall be checked with a vibrating- maximum capacity of the scale; however, this will vary with the
performance characteristics of the scale and the required accuracy of the
reed tachometer or other suitable device at an interval not to
determination. Acceptable scales used for determining the mass for
exceed two years. If the vibrator manufacturer recommends a
concrete materials preferably should determine mass accurately to about
shorter verification interval or a verification procedure, the
0.1 % of total capacity and the foregoing precaution is applicable.
manufacturer’s recommendation shall be followed.
However, certain analytical and precision balances are exceptions to this
rule and should weigh accurately to 0.001 %. Particular care must be
NOTE 3—For information on size and frequency of various vibrators
exercised in measuring small quantities of material by determining the
and method to check vibrator frequency, see ACI 309R.
difference between two much larger masses.
5.6.2 External Vibrators—The two types of external vibra-
5.13 Temperature Measuring Device—The temperature
tors permitted are either table or plank. The external vibrator
measuring device shall conform to the requirements of Test
frequency shall be 3600 vibrations per minute (60 Hz) or
Method C1064/C1064M.
higher.
5.14 Concrete Mixer—A power-driven concrete mixer shall
5.6.3 Provisions shall be made for clamping the mold
be a revolving drum, tilting mixer, or suitable revolving pan or
securely to the apparatus for both types of vibrators.
revolving-paddle mixer capable of thoroughly mixing batches
NOTE 4—Vibratory impulses are frequently imparted to a table or plank
of the prescribed sizes at the required slump.
vibrator through electromagnetic means, or by use of an eccentric weight
on the shaft of an electric motor or on a separate shaft driven by a motor.
NOTE 6—Apan mixer is usually more suitable for mixing concrete with
less than 25 mm [1 in.] slump than a revolving drum mixer. The rate of
5.7 Small Tools—Tools and items such as shovels, pails,
rotation, degree of tilt, and rated capacity of tilting mixers are not always
trowels, wood float, blunted trowels, straightedge, feeler gage,
suitableforlaboratorymixedconcrete.Itmaybefounddesirabletoreduce
scoops, rulers, rubber gloves, and metal mixing bowls shall be
the rate of rotation, decrease the angle of tilt from the horizontal, and use
provided. the mixer at somewhat less than the manufacturer’s rated capacity.
TABLE 2 Diameter of Rod and Number of Roddings to be Used in Molding Test Specimens
Cylinders
Diameter of Cylinder, mm [in.] Diameter of Rod mm [in.] Number of Strokes/Layer
3 1
75[3]to<150[6] 10±2[ ⁄8 ± ⁄16]25
5 1
150[6] 16±2[ ⁄8 ± ⁄16]25
5 1
200[8] 16±2[ ⁄8 ± ⁄16]50
5 1
250[10] 16±2[ ⁄8 ± ⁄16]75
Beams and Prisms
2 2
Top Surface Area of Specimen, cm [in. ] Diameter of Rod mm [in.] Number of Roddings/Layer
3 1
160[25]orless 10±2[ ⁄8 ± ⁄16]25
2 2
3 1
165to310[26to49] 10±2[ ⁄8 ± ⁄16 ] one for each 7 cm [1 in. ] of surface
2 2
5 1
320[50]ormore 16±2[ ⁄8 ± ⁄16 ] one for each 14 cm [2 in. ] of surface
Horizontal Creep Cylinders
Diameter of Cylinder mm [in.] Diameter of Rod mm [in.] Number of Roddings/Layer
5 1
150[6] 16±2[ ⁄8 ± ⁄16 ] 50 total, 25 along both sides of axis
C192/C192M − 19
test ages, 3 months, 6 months, and 1 year are often used for both
6. Specimens
compressive and flexural strength tests. Other test ages may be required
6.1 CylindricalSpecimens—Cylinderdimensionsshallbeas
for other types of specimens.
stipulated in the specification, test method or practice for the
7. Preparation of Materials
laboratory studies being performed and shall meet the require-
mentsof6.4.Ifdimensionsarenotstipulatedinaspecification, 7.1 Temperature—Before mixing the concrete, bring the
test method, or practice, the specimen selected shall have a
concrete materials to room temperature in the range from 20 to
length that is twice the diameter and meet the requirements of 30°C[68to86°F],exceptwhenthetemperatureoftheconcrete
6.4. is stipulated. When a concrete temperature is stipulated, the
method proposed to obtain the concrete temperature needs
NOTE 7—The same cylinder size should be used for the reference
approval of the stipulator.
(control) concrete mixture and test concrete mixtures when conducting
comparative studies such as those required in Specification C494/C494M.
7.2 Cement—Store the cement in a dry place, in moisture-
For mixture proportioning of project concrete, it is preferable for the
proof containers, preferably made of metal. The cement shall
cylinder size in the laboratory to be the same as that specified for
be thoroughly mixed to provide a uniform supply throughout
acceptance testing.
the tests. It shall be passed through a 850-µm (No. 20) or finer
NOTE 8—When molds in SI units are required and not available,
equivalent inch-pound unit size mold should be permitted.
sieve to remove all lumps, remixed on a plastic sheet, and
returned to sample containers.
6.1.1 Cylindrical specimens for tests other than creep shall
be molded and allowed to harden with the axis of the cylinder
7.3 Aggregates—In order to preclude segregation of a
vertical.
coarse aggregate, separate into individual size fractions and for
6.1.2 Cylindrical creep specimens may be cast with the
each batch recombine in the proper proportions to produce the
cylindrical axis either vertical or horizontal and allowed to desired grading.
harden in the position in which cast.
NOTE 10—Only rarely is a coarse aggregate batched as a single size
fraction. The number of size fractions will generally be between 2 and 5
6.2 Prismatic Specimens—Beams for flexural strength,
for aggregate smaller than 60 mm [2 ⁄2 in.]. When a size fraction to be
prisms for freezing and thawing, bond, length change, volume
batched is present in amounts in excess of 10 %, the ratio of the opening
change, etc., shall be formed with their long axes horizontal,
ofthelargertothesmallersieveshouldnotexceed2.0.Morecloselysized
unless otherwise required by the method of test in question,
groups are sometimes advisable.
and shall conform in dimension to the requirements of the
7.3.1 Unless fine aggregate is separated into individual size
specific test method.
fractions, maintain it in a damp condition or restore to a damp
6.3 Other Specimens—Other shapes and sizes of specimens condition until use, to prevent segregation, unless material
for particular tests may be molded as desired following the
uniformly graded is subdivided into batch size lots using a
general procedures set forth in this practice. sample splitter with proper size openings. If unusual gradings
are being studied, the fine aggregate may need to be dried and
6.4 SpecimenSizeversusAggregateSize—Thediameterofa
separated into individual sizes. In this instance, if the total
cylindrical specimen or minimum cross-sectional dimension of
quantity of fine aggregate required is larger than can be
a rectangular section shall be at least three times the nominal
efficiently blended in a single unit, then the individual size
maximum size of the coarse aggregate in the concrete as
fractions should be determined in a mass required for each
defined in Terminology C125. When the nominal maximum
individual batch. When the total quantity of fine aggregate
size of the coarse aggregate exceeds 50 mm [2 in.], the sample
needed for the complete investigation is such that it can be
shall be treated by wet sieving through a 50 mm (2 in.) sieve
thoroughly mixed, blended, and maintained in a damp
as described in Practice C172/C172M, unless otherwise stipu-
condition, then it should be handled in that manner. Determine
lated.
the specific gravity and absorption of aggregates in accordance
6.5 Number of Specimens—The number of specimens and
with either Test Methods C127 or C128.
the number of test batches are dependent on established
7.3.2 Before incorporating in concrete, prepare the aggre-
practice and the nature of the test program. Guidance is usually
gate to ensure a definite and uniform condition of moisture.
given in the test method or specification for which the
Determine the weight of aggregate to be used in the batch by
specimens are made. Usually three or more specimens are
one of the following procedures:
molded for each test age and test condition unless otherwise
7.3.2.1 Determine the mass of low-absorption aggregates
specified (Note 9). Specimens involving a given variable
(absorption less than 1.0 %) in the room-dry condition with
should be made from three separate batches mixed on different
allowance made for the amount of water that will be absorbed
days. An equal number of specimens for each variable should
from the unset concrete (Note 11). This procedure is particu-
be made on any given day. When it is impossible to make at
larly useful for coarse aggregate which must be batched as
leastonespecimenforeachvariableonagivenday,themixing
individual sizes; because of the danger of segregation it can be
of the entire series of specimens should be completed in as few
used for fine aggregate only when the fine aggregate is
days as possible, and one of the mixtures should be repeated
separated into individual size fractions.
each day as a standard of comparison.
NOTE 11—When using aggregates with low absorption in room-dry
NOTE 9—Test ages often used are 7 and 28 days for compressive condition the amount of water that will be absorbed by the aggregates
strength tests, or 14 and 28 days for flexural strength tests. Specimens before the concrete sets may be assumed to be 80 % of the difference
containingTypeIIIcementareoftentestedat1,3,7,and28days.Forlater between the 24-h absorption of the aggregates determined by Test
C192/C192M − 19
Methods C127 or C128, and the amount of water in the pores of the
retarding admixtures, should not be intermixed prior to their
aggregates in their room-dry state, as determined by Test Method C566.
additiontoconcrete.Thetime,sequence,andmethodofadding
some admixtures to a batch of concrete can have important
7.3.2.2 Weigh the individual size fractions of aggregate
separately, recombine them into a tared container in the effects on concrete properties such as time of set and air
content. The method selected must remain unchanged from
amounts required for the batch, and immerse them in water for
atleast24hpriortouse.Aftertheimmersionperiod,decantthe batch to batch.
excess water and determine the combined weight of aggregate
NOTE 12—The mixing apparatus and accessories shall be thoroughly
and mixing water. Allowance shall be made for the amount of
cleaned to ensure that chemical additions or admixtures used in dissimilar
water absorbed by the aggregate. Determine the moisture
batche
...

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: C192/C192M − 18 C192/C192M − 19
Standard Practice for
Making and Curing Concrete Test Specimens in the
Laboratory
This standard is issued under the fixed designation C192/C192M; 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 test specimens of concrete in the laboratory under accurate control
of materials and test conditions using concrete that can be consolidated by rodding or vibration as described herein.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other, and values from the two systems shall not be combined.
1.3 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. )
1.4 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:
C31/C31M Practice for Making and Curing Concrete Test Specimens in the Field
C70 Test Method for Surface Moisture in Fine Aggregate
C125 Terminology Relating to Concrete and Concrete Aggregates
C127 Test Method for Relative Density (Specific Gravity) and Absorption of Coarse Aggregate
C128 Test Method for Relative Density (Specific Gravity) and Absorption of Fine Aggregate
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
C494/C494M Specification for Chemical Admixtures for Concrete
C511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic
Cements and Concretes
C566 Test Method for Total Evaporable Moisture Content of Aggregate by Drying
C617/C617M Practice for Capping Cylindrical Concrete Specimens
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 Dec. 1, 2018Dec. 1, 2019. Published January 2019February 2020. Originally approved in 1944. Last previous edition approved in 20162018 as
C192/C192M – 16a.C192/C192M – 18. DOI: 10.1520/C0192_C0192M-18.10.1520/C0192_C0192M-19.
See section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standards, Vol 04.02.
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
C192/C192M − 19
C1064/C1064M Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete
C1077 Practice for Agencies Testing Concrete and Concrete Aggregates for Use in Construction and Criteria for Testing Agency
Evaluation
C1611/C1611M Test Method for Slump Flow of Self-Consolidating Concrete
C1758/C1758M Practice for Fabricating Test Specimens with Self-Consolidating Concrete
2.2 American Concrete Institute Publications:
211.3 Practice for Selecting Proportions for No-Slump Concrete
309R Guide for Consolidation of Concrete
3. Terminology
3.1 For definitions of terms used in this practice, refer to Terminology C125.
4. Significance and Use
4.1 This practice provides standardized requirements for preparation of materials, mixing concrete, and making and curing
concrete test specimens under laboratory conditions.
4.2 If specimen preparation is controlled as stipulated herein, the specimens may be used to develop information for the
following purposes:
4.2.1 Mixture proportioning for project concrete,
4.2.2 Evaluation of different mixtures and materials,
4.2.3 Correlation with nondestructive tests, and
4.2.4 Providing specimens for research purposes.
NOTE 1—The concrete test results for concrete specimens made and cured using this practice are widely used. They may be the basis for acceptance
testing for project concrete, research evaluations, and other studies. Careful and knowledgeable handling of materials, mixing concrete, molding test
specimens, and curing test specimens is necessary. Many laboratories performing this important work are independently inspected or accredited. Practice
C1077 identifies and defines the duties, responsibilities, and minimum technical qualification requirements of laboratory personnel and the minimum
requirements for equipment used in testing concrete and concrete aggregates.
5. Apparatus
5.1 Molds, General—Molds for specimens or fastenings thereto in contact with the concrete shall be made of steel, cast iron,
or other nonabsorbent material, nonreactive with concrete containing portland or other hydraulic cements. Molds shall conform
to the dimensions and tolerances specified in the method for which the specimens are required. Molds shall hold their dimensions
and shape under all conditions of use. Watertightness of molds during use shall be judged by their ability to hold water poured into
them. Test procedures for watertightness are given in the section on Test Methods for Elongation, Absorption, and Watertightness
of Specification C470/C470M. A suitable sealant, such as heavy grease, modeling clay, or microcrystalline wax, shall be used
where necessary to prevent leakage through the joints. Positive means shall be provided to hold base plates firmly to the molds.
Reusable molds shall be lightly coated with mineral oil or a suitable nonreactive release material before use.
5.2 Cylinder Molds:
5.2.1 Molds for Casting Specimens Vertically shall conform to the requirements of 5.1 and Specification C470/C470M.
5.2.2 Horizontal Molds for Creep Test Cylinders shall conform to the requirements of 5.1 and to the requirements for symmetry
and dimensional tolerance in the section on General Requirements except for verticality requirements of Specification
C470/C470M. The use of horizontal molds is intended only for creep specimens that contain axially embedded strain gages. Molds
for creep cylinders to be filled while supported in a horizontal position shall have a filling slot parallel to the axis of the mold which
extends the full length to receive the concrete. The width of the slot shall be one half the diameter of the specimen. If necessary
the edges of the slot shall be reinforced to maintain dimensional stability. Unless specimens are to be capped or ground to produce
plane ends, the molds shall be provided with two machined metal end plates at least 25 mm [1 in.] thick and the working surfaces
shall comply with the requirements for planeness and surface roughness given in the section on Capping Plates of Practice
C617/C617M. Provision shall be made for fixing both end plates firmly to the mold. The inside surface of each end plate shall be
provided with at least three lugs or studs approximately 25 mm [1 in.] long, firmly fastened to the plate for embedment in the
concrete. One base plate shall be drilled from the inside at an angle to permit the lead wire from the strain gage to exit the specimen
through the edge of the plate. Provision shall be made for accurately positioning the strain gage. All necessary holes shall be as
small as possible to minimize disturbance to subsequent strain measurements and shall be sealed to prevent leakage.
5.3 Beam and Prism Molds shall be rectangular in shape (unless otherwise specified) and of the dimensions required to produce
the desired specimen size. The inside surfaces of the molds shall be smooth and free from indentations. The sides, bottom, and
ends shall be at right angles to each other and shall be straight and true and free of warpage. Maximum variation from the nominal
1 1
cross section shall not exceed 3 mm [ ⁄8 in.] for molds with depth or breadth of 150 mm [6 in.] or more, or 2 mm [ ⁄16 in.] for molds
Available from American Concrete Institute (ACI), P.O. Box 9094, Farmington Hills, MI 48333-9094, http://www.aci-int.org.
C192/C192M − 19
of smaller depth or breadth. Except for flexure specimens, molds shall not vary from the nominal length by more than 2 mm
1 1
[ ⁄16 in.]. Flexure molds shall not be shorter than 2 mm [ ⁄16 in.] of the required length, but may exceed it by more than that amount.
5.4 Tamping Rod—A round, smooth, straight, steel rod with a diameter conforming to the requirements in Table 2. The length
of the tamping rod shall be at least 100 mm [4 in.] greater than the depth of the mold in which rodding is being performed, but
not greater than 600 mm [24 in.] in overall length (see Note 2). The rod shall have the tamping end or both ends rounded to a
hemispherical tip of the same diameter as the rod.
NOTE 2—A rod length of 400 mm [16 in.] to 600 mm [24 in.] meets the requirements of the following: Practice C31/C31MC31/C31M,, Test Method
C138/C138MC138/C138M,, Test Method C143/C143MC143/C143M,, Test Method C173/C173MC173/C173M,, and Test Method C231/C231MC231/
C231M.
5.5 Mallets—A mallet with a rubber or rawhide head weighing 0.6 6 0.2 kg [1.25 6 0.50 lb] shall be used.
5.6 Vibrators:
5.6.1 Internal Vibrators—The vibrator frequency shall be at least 9000 vibrations per minute [150 Hz] while the vibrator is
operating in the concrete. The diameter of a round vibrator shall be no more than one fourth the diameter of the cylinder mold or
one fourth the width of the beam or prism mold. Other shaped vibrators shall have a perimeter equivalent to the circumference
of an appropriate round vibrator. The combined length of the vibrator shaft and vibrating element shall exceed the depth of the
section being vibrated by at least 75 mm [3 in.]. The vibrator frequency shall be checked with a vibrating-reed tachometer or other
suitable device at an interval not to exceed two years. If the vibrator manufacturer recommends a shorter verification interval or
a verification procedure, the manufacturer’s recommendation shall be followed.
NOTE 3—For information on size and frequency of various vibrators and method to check vibrator frequency, see ACI 309R.
5.6.2 External Vibrators—The two types of external vibrators permitted are either table or plank. The external vibrator
frequency shall be 3600 vibrations per minute (60 Hz) or higher.
5.6.3 Provisions shall be made for clamping the mold securely to the apparatus for both types of vibrators.
NOTE 4—Vibratory impulses are frequently imparted to a table or plank vibrator through electromagnetic means, or by use of an eccentric weight on
the shaft of an electric motor or on a separate shaft driven by a motor.
5.7 Small Tools—Tools and items such as shovels, pails, trowels, wood float, blunted trowels, straightedge, feeler gage, scoops,
rulers, rubber gloves, and metal mixing bowls shall be provided.
5.8 Slump and Slump Flow Apparatus—The apparatus for measurement of slump or slump flow shall conform to the
requirements of Test Method C143/C143M. or Test Method C1611/C1611M, respectively.
5.9 Sampling and Mixing Pan—The pan shall be flat-bottom and of heavy-gage metal, watertight, of convenient depth, and of
sufficient capacity to allow easy mixing by shovel or trowel of the entire batch; or, if mixing is by machine, to receive the entire
batch on discharge of the mixer and allow remixing in the pan by trowel or shovel.
5.10 Wet-Sieving Equipment—If wet-sieving is required, the equipment shall conform to the requirements of Practice
C172/C172M.
5.11 Air Content Apparatus—The apparatus for measuring air content shall conform to the requirements of either Test Methods
C231/C231M or C173/C173M.
5.12 Scales—Scales for determining the mass of batches of materials and concrete shall be accurate within 0.3 % of the test load
at any point within the range of use.
NOTE 5—In general the mass of small quantities should not be determined on large capacity scales. In many applications the smallest mass determined
on a scale should be greater than about 10 % of the maximum capacity of the scale; however, this will vary with the performance characteristics of the
TABLE 1 Number of Layers Required for Specimens
Specimen Type and Size Mode of Numbers of Layers
Consolidation of Approximate
Equal Depth
Cylinders:
Diameter, mm [in.]
75 to 100 [3 or 4] rodding 2
150 [6] rodding 3
225 [9] rodding 4
up to 225 [9] vibration 2
Prisms and horizontal creep Cylinders:
Depth, mm [in.]
up to 200 [8] rodding 2
over 200 [8] rodding 3 or more
up to 200 [8] vibration 1
over 200 [8] vibration 2 or more
C192/C192M − 19
TABLE 2 Diameter of Rod and Number of Roddings to be Used in Molding Test Specimens
Cylinders
Diameter of Cylinder, mm [in.] Diameter of Rod mm [in.] Number of Strokes/Layer
3 1
75 [3] to < 150 [6] 10 ± 2 [ ⁄8 ± ⁄16 ] 25
5 1
150 [6] 16 ± 2 [ ⁄8 ± ⁄16 ] 25
5 1
200 [8] 16 ± 2 [ ⁄8 ± ⁄16 ] 50
5 1
250 [10] 16 ± 2 [ ⁄8 ± ⁄16 ] 75
Beams and Prisms
2 2
Top Surface Area of Specimen, cm [in. ] Diameter of Rod mm [in.] Number of Roddings/Layer
3 1
160 [25] or less 10 ± 2 [ ⁄8 ± ⁄16 ] 25
2 2
3 1
165 to 310 [26 to 49] 10 ± 2 [ ⁄8 ± ⁄16 ] one for each 7 cm [1 in. ] of surface
2 2
5 1
320 [50] or more 16 ± 2 [ ⁄8 ± ⁄16 ] one for each 14 cm [2 in. ] of surface
Horizontal Creep Cylinders
Diameter of Cylinder mm [in.] Diameter of Rod mm [in.] Number of Roddings/Layer
5 1
150 [6] 16 ± 2 [ ⁄8 ± ⁄16 ] 50 total, 25 along both sides of axis
scale and the required accuracy of the determination. Acceptable scales used for determining the mass for concrete materials preferably should determine
mass accurately to about 0.1 % of total capacity and the foregoing precaution is applicable. However, certain analytical and precision balances are
exceptions to this rule and should weigh accurately to 0.001 %. Particular care must be exercised in measuring small quantities of material by determining
the difference between two much larger masses.
5.13 Temperature Measuring Device—The temperature measuring device shall conform to the requirements of Test Method
C1064/C1064M.
5.14 Concrete Mixer—A power-driven concrete mixer shall be a revolving drum, tilting mixer, or suitable revolving pan or
revolving-paddle mixer capable of thoroughly mixing batches of the prescribed sizes at the required slump.
NOTE 6—A pan mixer is usually more suitable for mixing concrete with less than 25 mm [1 in.] slump than a revolving drum mixer. The rate of rotation,
degree of tilt, and rated capacity of tilting mixers are not always suitable for laboratory mixed concrete. It may be found desirable to reduce the rate of
rotation, decrease the angle of tilt from the horizontal, and use the mixer at somewhat less than the manufacturer’s rated capacity.
6. Specimens
6.1 Cylindrical Specimens—Cylinder dimensions shall be as stipulated in the specification, test method or practice for the
laboratory studies being performed and shall meet the requirements of 6.4. If dimensions are not stipulated in a specification, test
method, or practice, the specimen selected shall have a length that is twice the diameter and meet the requirements of 6.4.
NOTE 7—The same cylinder size should be used for the reference (control) concrete mixture and test concrete mixtures when conducting comparative
studies such as those required in Specification C494/C494M. For mixture proportioning of project concrete, it is preferable for the cylinder size in the
laboratory to be the same as that specified for acceptance testing.
NOTE 8—When molds in SI units are required and not available, equivalent inch-pound unit size mold should be permitted.
6.1.1 Cylindrical specimens for tests other than creep shall be molded and allowed to harden with the axis of the cylinder
vertical.
6.1.2 Cylindrical creep specimens may be cast with the cylindrical axis either vertical or horizontal and allowed to harden in
the position in which cast.
6.2 Prismatic Specimens—Beams for flexural strength, prisms for freezing and thawing, bond, length change, volume change,
etc., shall be formed with their long axes horizontal, unless otherwise required by the method of test in question, and shall conform
in dimension to the requirements of the specific test method.
6.3 Other Specimens—Other shapes and sizes of specimens for particular tests may be molded as desired following the general
procedures set forth in this practice.
6.4 Specimen Size versus Aggregate Size—The diameter of a cylindrical specimen or minimum cross-sectional dimension of a
rectangular section shall be at least three times the nominal maximum size of the coarse aggregate in the concrete as defined in
Terminology C125. When the nominal maximum size of the coarse aggregate exceeds 50 mm [2 in.], the sample shall be treated
by wet sieving through a 50 mm (2 in.) sieve as described in Practice C172/C172M, unless otherwise stipulated.
6.5 Number of Specimens—The number of specimens and the number of test batches are dependent on established practice and
the nature of the test program. Guidance is usually given in the test method or specification for which the specimens are made.
Usually three or more specimens are molded for each test age and test condition unless otherwise specified (Note 9). Specimens
involving a given variable should be made from three separate batches mixed on different days. An equal number of specimens
for each variable should be made on any given day. When it is impossible to make at least one specimen for each variable on a
given day, the mixing of the entire series of specimens should be completed in as few days as possible, and one of the mixtures
should be repeated each day as a standard of comparison.
NOTE 9—Test ages often used are 7 and 28 days for compressive strength tests, or 14 and 28 days for flexural strength tests. Specimens containing
Type III cement are often tested at 1, 3, 7, and 28 days. For later test ages, 3 months, 6 months, and 1 year are often used for both compressive and flexural
strength tests. Other test ages may be required for other types of specimens.
C192/C192M − 19
7. Preparation of Materials
7.1 Temperature—Before mixing the concrete, bring the concrete materials to room temperature in the range from 20 to 30°C
[68 to 86°F], except when the temperature of the concrete is stipulated. When a concrete temperature is stipulated, the method
proposed to obtain the concrete temperature needs approval of the stipulator.
7.2 Cement—Store the cement in a dry place, in moisture-proof containers, preferably made of metal. The cement shall be
thoroughly mixed to provide a uniform supply throughout the tests. It shall be passed through a 850-μm (No. 20) or finer sieve
to remove all lumps, remixed on a plastic sheet, and returned to sample containers.
7.3 Aggregates—In order to preclude segregation of a coarse aggregate, separate into individual size fractions and for each batch
recombine in the proper proportions to produce the desired grading.
NOTE 10—Only rarely is a coarse aggregate batched as a single size fraction. The number of size fractions will generally be between 2 and 5 for
aggregate smaller than 60 mm [2 ⁄2 in.]. When a size fraction to be batched is present in amounts in excess of 10 %, the ratio of the opening of the larger
to the smaller sieve should not exceed 2.0. More closely sized groups are sometimes advisable.
7.3.1 Unless fine aggregate is separated into individual size fractions, maintain it in a damp condition or restore to a damp
condition until use, to prevent segregation, unless material uniformly graded is subdivided into batch size lots using a sample
splitter with proper size openings. If unusual gradings are being studied, the fine aggregate may need to be dried and separated
into individual sizes. In this instance, if the total quantity of fine aggregate required is larger than can be efficiently blended in a
single unit, then the individual size fractions should be determined in a mass required for each individual batch. When the total
quantity of fine aggregate needed for the complete investigation is such that it can be thoroughly mixed, blended, and maintained
in a damp condition, then it should be handled in that manner. Determine the specific gravity and absorption of aggregates in
accordance with either Test Methods C127 or C128.
7.3.2 Before incorporating in concrete, prepare the aggregate to ensure a definite and uniform condition of moisture. Determine
the weight of aggregate to be used in the batch by one of the following procedures:
7.3.2.1 Determine the mass of low-absorption aggregates (absorption less than 1.0 %) in the room-dry condition with allowance
made for the amount of water that will be absorbed from the unset concrete (Note 11). This procedure is particularly useful for
coarse aggregate which must be batched as individual sizes; because of the danger of segregation it can be used for fine aggregate
only when the fine aggregate is separated into individual size fractions.
NOTE 11—When using aggregates with low absorption in room-dry condition the amount of water that will be absorbed by the aggregates before the
concrete sets may be assumed to be 80 % of the difference between the 24-h absorption of the aggregates determined by Test Methods C127 or C128,
and the amount of water in the pores of the aggregates in their room-dry state, as determined by Test Method C566.
7.3.2.2 Weigh the individual size fractions of aggregate separately, recombine them into a tared container in the amounts
required for the batch, and immerse them in water for at least 24 h prior to use. After the immersion period, decant the excess water
and determine the combined weight of aggregate and mixing water. Allowance shall be made for the amount of water absorbed
by the aggregate. Determine the moisture content of the aggregates in accordance with Test Method C70 or Test Method C566.
7.3.2.3 Bring the aggregate to a saturated condition and maintain it in this condition, with surface moisture contained in
sufficiently small amounts to preclude loss by draining, at least 24 h prior to use. When this method is used, the moisture content
of the aggregate must be determined to permit calculation of proper quantities of the damp aggregate. Th
...