ASTM C469/C469M-22

Standard Test Method for Static Modulus of Elasticity and Poisson's Ratio of Concrete in Compression

SIGNIFICANCE AND USE
3.1 This test method provides a stress to strain ratio value and a ratio of lateral to longitudinal strain for hardened concrete at whatever age and curing conditions may be designated.  
3.2 The modulus of elasticity and Poisson's ratio values, applicable within the customary working stress range (0 to 40 % of ultimate concrete strength), are used in sizing of reinforced and nonreinforced structural members, establishing the quantity of reinforcement, and computing stress for observed strains.  
3.3 The modulus of elasticity values obtained will usually be less than moduli derived under rapid load application (dynamic or seismic rates, for example), and will usually be greater than values under slow load application or extended load duration, given other test conditions being the same.
SCOPE
1.1 This test method covers determination of (1) chord modulus of elasticity (Young's) and (2) Poisson's ratio of molded concrete cylinders and diamond-drilled concrete cores when under longitudinal compressive stress. Chord modulus of elasticity and Poisson's ratio are defined in Terminology E6.  
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 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.  
1.3 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.  
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: 31-Mar-2022
• 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 C670-24a - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Feb-2024
• Refers: ASTM C670-24 - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Jan-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 C39/C39M-23 - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Dec-2023
• Refers: ASTM C42/C42M-18 - Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
• Effective Date: 15-Mar-2018
• Refers: ASTM C31/C31M-18 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Jan-2018
• Refers: ASTM C39/C39M-17b - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Aug-2017
• Refers: ASTM C174/C174M-17 - Standard Test Method for Measuring Thickness of Concrete Elements Using Drilled Concrete Cores
• Effective Date: 01-May-2017
• Refers: ASTM C42/C42M-16 - Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
• Effective Date: 01-Oct-2016
• Refers: ASTM C39/C39M-16b - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Aug-2016
• Refers: ASTM C39/C39M-16a - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Jul-2016
• Refers: ASTM C174/C174M-16 - Standard Test Method for Measuring Thickness of Concrete Elements Using Drilled Concrete Cores
• Effective Date: 01-Jun-2016
• Refers: ASTM C192/C192M-16 - Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory
• Effective Date: 01-Feb-2016
• Refers: ASTM C31/C31M-15ae1 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 15-Nov-2015

Overview

ASTM C469/C469M-22: Standard Test Method for Static Modulus of Elasticity and Poisson's Ratio of Concrete in Compression sets out procedures for determining the chord modulus of elasticity (Young’s modulus) and Poisson's ratio of concrete using either molded cylinders or diamond-drilled cores under compressive stress. Developed by ASTM International, this standard is widely referenced in construction, civil engineering, and material science to assess concrete’s mechanical behavior. The data obtained through this test method are critical for both reinforced and nonreinforced concrete designs, supporting proper structural analysis and design safety.

Key Topics

• Modulus of Elasticity: Measures the stress to strain ratio for hardened concrete, providing insight into its stiffness and deformation under load.
• Poisson's Ratio: Determines the ratio of lateral (transverse) to longitudinal strain, indicating dimensional changes perpendicular to the applied load.
• Specimen Types: Both laboratory-molded cylindrical specimens and field-extracted diamond-drilled concrete cores can be tested.
• Load Conditions: The standard focuses on static loading, typical in service conditions, and covers testing within 0 to 40% of the ultimate concrete strength, which is the standard working range in construction applications.
• Testing Apparatus: Specifies use of calibrated machines and measurement devices, such as compressometers and extensometers, for accurate strain and deformation readings.
• Precision and Reproducibility: Includes guidelines on acceptable variations for both single-operator and multilaboratory environments, ensuring reliability of the results.
• Reporting Requirements: Outlines detailed information to document, including specimen identification, dimensions, curing history, measured properties, and test conditions.

Applications

ASTM C469/C469M-22 plays a pivotal role in structural engineering and construction quality assurance by providing methodologies for:

• Structural Design: Calculating modulus of elasticity and Poisson's ratio is essential for sizing structural elements, selecting reinforcement quantities, and predicting concrete behavior within the designed load range.
• Quality Control and Material Characterization: Ensures the consistency and suitability of concrete mixtures used in both precast and cast-in-place applications.
• Forensic Analysis and Evaluation: Testing drilled cores from existing structures allows engineers to assess the condition and performance of aged or in-service concrete.
• Compliance with Building Codes: Meeting ASTM C469/C469M-22 ensures adherence to industry-recognized best practices and supports integration with other testing standards frequently cited in codes and specifications.

Related Standards

Several ASTM standards complement and support the implementation of ASTM C469/C469M-22:

• ASTM C39/C39M - Test Method for Compressive Strength of Cylindrical Concrete Specimens
• ASTM C192/C192M - Practice for Making and Curing Concrete Test Specimens in the Laboratory
• ASTM C31/C31M - Practice for Making and Curing Concrete Test Specimens in the Field
• ASTM C42/C42M - Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
• ASTM C617 - Practice for Capping Cylindrical Concrete Specimens
• ASTM E4 - Practices for Force Calibration and Verification of Testing Machines
• ASTM E83 - Practice for Verification and Classification of Extensometer Systems

Implementing ASTM C469/C469M-22 supports accurate determination of concrete’s modulus of elasticity and Poisson's ratio, providing valuable data for structural analysis, material assessment, and compliance with modern construction standards. This ensures greater confidence in the performance and safety of concrete structures across various sectors in the built environment.

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: C469/C469M − 22
Standard Test Method for
Static Modulus of Elasticity and Poisson’s Ratio of Concrete
in Compression
This standard is issued under the fixed designation C469/C469M; 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* C174/C174MTestMethodforMeasuringThicknessofCon-
crete Elements Using Drilled Concrete Cores
1.1 This test method covers determination of (1) chord
C192/C192MPractice for Making and Curing ConcreteTest
modulus of elasticity (Young’s) and (2) Poisson’s ratio of
Specimens in the Laboratory
molded concrete cylinders and diamond-drilled concrete cores
C617Practice for Capping Cylindrical Concrete Specimens
whenunderlongitudinalcompressivestress.Chordmodulusof
C670Practice for Preparing Precision and Bias Statements
elasticity and Poisson’s ratio are defined in Terminology E6.
for Test Methods for Construction Materials
1.2 The values stated in either SI units or inch-pound units
E4Practices for Force Calibration and Verification of Test-
are to be regarded separately as standard. The values stated in
ing Machines
each system may not be exact equivalents; therefore, each
E6Terminology Relating to Methods of Mechanical Testing
system shall be used independently of the other. Combining
E83Practice for Verification and Classification of Exten-
values from the two systems may result in non-conformance
someter Systems
with the standard.
E177Practice for Use of the Terms Precision and Bias in
1.3 This standard does not purport to address all of the ASTM Test Methods
safety concerns, if any, associated with its use. It is the
2.2 ASTM Adjuncts:
responsibility of the user of this standard to establish appro-
Compressometers (two drawings) and Extensometers (two
priate safety, health, and environmental practices and deter-
drawings)
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
3. Significance and Use
dance with internationally recognized principles on standard-
3.1 This test method provides a stress to strain ratio value
ization established in the Decision on Principles for the
and a ratio of lateral to longitudinal strain for hardened
Development of International Standards, Guides and Recom-
concrete at whatever age and curing conditions may be
mendations issued by the World Trade Organization Technical
designated.
Barriers to Trade (TBT) Committee.
3.2 The modulus of elasticity and Poisson’s ratio values,
2. Referenced Documents applicable within the customary working stress range (0 to
40% of ultimate concrete strength), are used in sizing of
2.1 ASTM Standards:
reinforced and nonreinforced structural members, establishing
C31/C31MPractice for Making and Curing Concrete Test
the quantity of reinforcement, and computing stress for ob-
Specimens in the Field
served strains.
C39/C39MTest Method for Compressive Strength of Cylin-
3.3 The modulus of elasticity values obtained will usually
drical Concrete Specimens
C42/C42MTest Method for Obtaining and Testing Drilled be less than moduli derived under rapid load application
(dynamic or seismic rates, for example), and will usually be
Cores and Sawed Beams of Concrete
greater than values under slow load application or extended
load duration, given other test conditions being the same.
This test method is under the jurisdiction of ASTM Committee C09 on
Concrete and ConcreteAggregatesand is the direct responsibility of Subcommittee
4. Apparatus
C09.61 on Testing for Strength.
Current edition approved April 1, 2022. Published June 2022. Originally
4.1 Testing Machine—Use a testing machine capable of
ɛ1
approved in 1961. Last previous edition approved in 2014 as C469–14 . DOI:
imposing a load at the rate and of the magnitude prescribed in
10.1520/C0469_C0469M-22.
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 Available from ASTM International Headquarters. Order Adjunct No.
the ASTM website. ADJC0469-E-PDF. Adjunct converted to digital format in 2021.
*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
C469/C469M − 22
6.4. The machine shall conform to the requirements of Prac- reading) is equal to the sum of the displacement due to
tices E4 (Constant-Rate of-Traverse CRT-Type Testing Ma- specimen deformation and the displacement due to rotation of
chines section). The spherical head and bearing blocks shall the yoke about the pivot rod (see Fig. 2).
conform to theApparatus Section of Test Method C39/C39M. 4.2.1 Measure deformation by a dial gauge used directly or
3 with a lever multiplying system, by a wire strain gauge, or by
4.2 Compressometer —For determining the modulus of
a linear variable differential transformer. If the distances of the
elasticity use a bonded (Note 1) or unbonded sensing device
pivotrodandthegaugefromtheverticalplanepassingthrough
that measures to the nearest 5 millionths the average deforma-
the support points of the rotating yoke are equal, the deforma-
tion of two diametrically opposite gauge lines, each parallel to
tion of the specimen is equal to one-half the gauge reading. If
the axis, and each centered about midheight of the specimen.
these distances are not equal, calculate the deformation as
The effective length of each gauge line shall be not less than
follows:
three times the maximum size of the aggregate in the concrete
d 5 ge / e 1e (1)
nor more than two thirds the height of the specimen; the ~ !
r r g
preferred length of the gauge line is one half the height of the
where:
specimen.Eitherusegaugepointsembeddedinorcementedto
d = total deformation of the specimen throughout the effec-
the specimen, and read deformation of the two lines indepen-
tive gauge length, µm [µin.],
dently; or use a compressometer (such as is shown in Fig. 1)
g = gauge reading, µm [µin.],
consisting of two yokes, one of which (see B, Fig. 1) is rigidly
e = the perpendicular distance, measured to the nearest 0.2
r
attached to the specimen and the other (see C, Fig. 1) attached
mm [0.01 in.] from the pivot rod to the vertical plane
at two diametrically opposite points so that it is free to rotate.
passing through the two support points of the rotating
At one point on the circumference of the rotating yoke,
yoke, and
midwaybetweenthetwosupportpoints,useapivotrod(seeA,
e = the perpendicular distance, measured to the nearest 0.2
g
Fig. 1) to maintain a constant distance between the two yokes.
mm [0.01 in.] from the gauge to the vertical plane
Attheoppositepointonthecircumferenceoftherotatingyoke,
passing through the two support points of the rotating
the change in distance between the yokes (that is, the gauge
yoke.
Procedures for calibrating strain-measuring devices are
given in Practice E83.
NOTE 1—Although bonded strain gauges are satisfactory on dry
specimens,theymaybedifficult,ifnotimpossible,tomountonspecimens
continually moist-cured until tested.
4.3 Extensometer —If Poisson’s ratio is desired, the trans-
verse strain shall be determined (1) by an unbonded extensom-
eter capable of measuring to the nearest 0.5 µm [25 µin.] the
change in diameter at the midheight of the specimen, or (2)by
two bonded strain gauges (Note 1) mounted circumferentially
at diametrically opposite points at the midheight of the
specimen and capable of measuring circumferential strain to
the nearest 5 millionths. A combined compressometer and
extensometer (Fig. 3) is a convenient unbonded device. This
apparatus shall contain a third yoke (consisting of two equal
d = displacement due to specimen deformation
r = displacement due to rotation of the yoke about the pivot rod
a = location of gauge
b = support point of the rotating yoke
c = location of pivot rod
g = gauge reading
FIG. 1 Suitable Compressometer FIG. 2 Diagram of Displacements
C469/C469M − 22
e' = theperpendiculardistance,measuredtothenearest0.2
g
mm [0.01 in.] from the gauge to the vertical plane
passingthroughthesupportpointsofthemiddleyoke.
4.4 Balance or Scale, accurate to 50 g [0.1 lb] shall be used
if necessary.
5. Test Specimens
5.1 Molded Cylindrical Specimens—Mold test cylinders in
accordance with the requirements for compression test speci-
mens in Practice C192/C192M, or in Practice C31/C31M.
Subjectspecimenstothespecifiedcuringconditionsandtestat
the age for which the elasticity information is desired. Test
specimens within 1 h after removal from the curing or storage
room. Specimens removed from a moist room for test shall be
kept moist by a wet cloth covering during the interval between
removal and test.
5.2 Drilled Core Specimens—Cores shall comply with the
requirementsfordrilling,andmoistureconditioningapplicable
tocompressivestrengthspecimensinTestMethodC42/C42M,
except that only diamond-drilled cores having a length-to-
diameter ratio greater than 1.50 shall be used. Requirements
relativetostorageandtoambientconditionsimmediatelyprior
to test shall be the same as for molded cylindrical specimens.
5.3 The ends of the test specimens shall be made perpen-
dicular to the axis 60.001 rad [60.5°] and plane within 0.05
mm [0.002 in.]. If the specimen as cast does not meet the
FIG. 3 Suitable Combined Compressometer-Extensometer
planeness requirements, planeness shall be accomplished by
cappinginaccordancewithPracticeC617,orbylapping,orby
grinding. It is not prohibited to repair aggregate popouts that
occur at the ends of specimens, provided the total area of
segments) located halfway between the two compressometer
popouts does not exceed 10% of the specimen area and the
yokes and attached to the specimen at two diametrically
repairsaremadebeforecappingorgrindingiscompleted(Note
oppositepoints.Midwaybetweenthesepointsuseashortpivot
2). Planeness will be considered within tolerance when a
rod (A', see Fig. 3), adjacent to the long pivot rod, to maintain
0.05mm [0.002 in.] feeler gauge will not pass between the
a constant distance between the bottom and middle yokes.
specimen surface and a straight edge held against the surface.
Hinge the middle yoke at the pivot point to permit rotation of
NOTE 2—Repairs may be made by epoxying the dislodged aggregate
the two segments of the yoke in the horizontal plane. At the
back in place or by filling the void with capping material and allowing
oppositepointonthecircumference,connectthetwosegments
adequate time for it to harden.
through a dial gauge or other sensing device capable of
5.4 Measure the diameter of the test specimen by caliper to
measuring transverse deformation to the nearest 1.27 µm [50
the nearest 0.2 mm [0.01 in.] by averaging two diameters
µin.]. If the distances of the hinge and the gauge from the
measured at right angles to each other near the center of the
vertical plane passing through the support points of the middle
length of the specimen. Use this average diameter to calculate
yoke are equal, the transverse deformation of the specimen
the cross-sectional area. Measure and report the length of a
diameter is equal to one-half the gauge reading. If these
moldedspecimen,includingcaps,tothenearest2mm[0.1in.].
distances are not equal, calculate the transverse deformation of
Me
...

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.
´1
Designation: C469/C469M − 14 C469/C469M − 22
Standard Test Method for
Static Modulus of Elasticity and Poisson’s Ratio of Concrete
in Compression
This standard is issued under the fixed designation C469/C469M; 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.
ε NOTE—Footnote 3 was editorially updated in February 2021.
1. Scope*
1.1 This test method covers determination of (1) chord modulus of elasticity (Young’s) and (2) Poisson’s ratio of molded concrete
cylinders and diamond-drilled concrete cores when under longitudinal compressive stress. Chord modulus of elasticity and
Poisson’s ratio are defined in Terminology E6.
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 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.
1.3 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.
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
C39/C39M Test Method for Compressive Strength of Cylindrical Concrete Specimens
C42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
C174/C174M Test Method for Measuring Thickness of Concrete Elements Using Drilled Concrete Cores
C192/C192M Practice for Making and Curing Concrete Test Specimens in the Laboratory
C617 Practice for Capping Cylindrical Concrete Specimens
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
E4 Practices for Force Calibration and Verification of Testing Machines
E6 Terminology Relating to Methods of Mechanical Testing
E83 Practice for Verification and Classification of Extensometer Systems
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
This test method 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, 2014April 1, 2022. Published April 2014June 2022. Originally approved in 1961. Last previous edition approved in 20102014 as
ɛ1
C469–10.–14 . DOI: 10.1520/C0469_C0469M-14E01.10.1520/C0469_C0469M-22.
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
C469/C469M − 22
2.2 ASTM Adjuncts:
Compressometers (two drawings) and Extensometers (two drawings)
3. Significance and Use
3.1 This test method provides a stress to strain ratio value and a ratio of lateral to longitudinal strain for hardened concrete at
whatever age and curing conditions may be designated.
3.2 The modulus of elasticity and Poisson’s ratio values, applicable within the customary working stress range (0 to 40 % of
ultimate concrete strength), are used in sizing of reinforced and nonreinforced structural members, establishing the quantity of
reinforcement, and computing stress for observed strains.
3.3 The modulus of elasticity values obtained will usually be less than moduli derived under rapid load application (dynamic or
seismic rates, for example), and will usually be greater than values under slow load application or extended load duration, given
other test conditions being the same.
4. Apparatus
4.1 Testing Machine—Use a testing machine capable of imposing a load at the rate and of the magnitude prescribed in 6.4. The
machine shall conform to the requirements of Practices E4 (Constant-Rate of-Traverse CRT-Type Testing Machines section). The
spherical head and bearing blocks shall conform to the Apparatus Section of Test Method C39/C39M.
4.2 Compressometer —For determining the modulus of elasticity use a bonded (Note 1) or unbonded sensing device that measures
to the nearest 5 millionths the average deformation of two diametrically opposite gauge lines, each parallel to the axis, and each
centered about midheight of the specimen. The effective length of each gauge line shall be not less than three times the maximum
size of the aggregate in the concrete nor more than two thirds the height of the specimen; the preferred length of the gauge line
is one half the height of the specimen. Either use gauge points embedded in or cemented to the specimen, and read deformation
of the two lines independently; or use a compressometer (such as is shown in Fig. 1) consisting of two yokes, one of which (see
B,Fig. 1) is rigidly attached to the specimen and the other (see C,Fig. 1) attached at two diametrically opposite points so that it
is free to rotate. At one point on the circumference of the rotating yoke, midway between the two support points, use a pivot rod
(see A,Fig. 1) to maintain a constant distance between the two yokes. At the opposite point on the circumference of the rotating
yoke, the change in distance between the yokes (that is, the gauge reading) is equal to the sum of the displacement due to specimen
deformation and the displacement due to rotation of the yoke about the pivot rod (see Fig. 2).
4.2.1 Measure deformation by a dial gauge used directly or with a lever multiplying system, by a wire strain gauge, or by a linear
variable differential transformer. If the distances of the pivot rod and the gauge from the vertical plane passing through the support
points of the rotating yoke are equal, the deformation of the specimen is equal to one-half the gauge reading. If these distances
are not equal, calculate the deformation as follows:
d 5 ge /~e 1e ! (1)
r r g
where:
d = total deformation of the specimen throughout the effective gauge length, μm [μin.],
g = gauge reading, μm [μin.],
e = the perpendicular distance, measured to the nearest 0.2 mm [0.01 in.] from the pivot rod to the vertical plane passing
r
through the two support points of the rotating yoke, and
e = the perpendicular distance, measured to the nearest 0.2 mm [0.01 in.] from the gauge to the vertical plane passing through
g
the two support points of the rotating yoke.
Procedures for calibrating strain-measuring devices are given in Practice E83.
NOTE 1—Although bonded strain gauges are satisfactory on dry specimens, they may be difficult, if not impossible, to mount on specimens continually
moist-cured until tested.
4.3 Extensometer —If Poisson’s ratio is desired, the transverse strain shall be determined (1) by an unbonded extensometer
Available from ASTM International Headquarters. Order Adjunct No. ADJC0469-E-PDF. Adjunct converted to digital format in 2021.
C469/C469M − 22
FIG. 1 Suitable Compressometer
d = displacement due to specimen deformation
r = displacement due to rotation of the yoke about the pivot rod
a = location of gauge
b = support point of the rotating yoke
c = location of pivot rod
g = gauge reading
FIG. 2 Diagram of Displacements
capable of measuring to the nearest 0.5 μm [25 μin.] the change in diameter at the midheight of the specimen, or (2) by two bonded
strain gauges (Note 1) mounted circumferentially at diametrically opposite points at the midheight of the specimen and capable
of measuring circumferential strain to the nearest 5 millionths. A combined compressometer and extensometer (Fig. 3) is a
convenient unbonded device. This apparatus shall contain a third yoke (consisting of two equal segments) located halfway between
the two compressometer yokes and attached to the specimen at two diametrically opposite points. Midway between these points
use a short pivot rod (A', see Fig. 3), adjacent to the long pivot rod, to maintain a constant distance between the bottom and middle
yokes. Hinge the middle yoke at the pivot point to permit rotation of the two segments of the yoke in the horizontal plane. At the
C469/C469M − 22
FIG. 3 Suitable Combined Compressometer-Extensometer
opposite point on the circumference, connect the two segments through a dial gauge or other sensing device capable of measuring
transverse deformation to the nearest 1.27 μm [50 μin.]. If the distances of the hinge and the gauge from the vertical plane passing
through the support points of the middle yoke are equal, the transverse deformation of the specimen diameter is equal to one-half
the gauge reading. If these distances are not equal, calculate the transverse deformation of the specimen diameter in accordance
with Eq 2.
d'5 g'e' /~e' 1e' ! (2)
h h g
where:
d' = transverse deformation of the specimen diameter, μm [μin.],
g' = transverse gauge reading, μm [μin.],
e' = the perpendicular distance, measured to the nearest 0.2 mm [0.01 in.] from the hinge to the vertical plane passing through
h
the support points of the middle yoke, and
e' = the perpendicular distance, measured to the nearest 0.2 mm [0.01 in.] from the gauge to the vertical plane passing through
g
the support points of the middle yoke.
4.4 Balance or Scale, accurate to 50 g [0.1 lb] shall be used if necessary.
5. Test Specimens
5.1 Molded Cylindrical Specimens—Mold test cylinders in accordance with the requirements for compression test specimens in
Practice C192/C192M, or in Practice C31/C31M. Subject specimens to the specified curing conditions and test at the age for which
the elasticity information is desired. Test specimens within 1 h after removal from the curing or storage room. Specimens removed
from a moist room for test shall be kept moist by a wet cloth covering during the interval between removal and test.
5.2 Drilled Core Specimens—Cores shall comply with the requirements for drilling, and moisture conditioning applicable to
compressive strength specimens in Test Method C42/C42M, except that only diamond-drilled cores having a length-to-diameter
C469/C469M − 22
ratio greater than 1.50 shall be used. Requirements relative to storage and to ambient conditions immediately prior to test shall be
the same as for molded cylindrical specimens.
5.3 The ends of the test specimens shall be made perpendicular to the axis 60.001 rad [60.5°] and plane within 0.05 mm [0.002
in.]. If the specimen as cast does not meet the planeness requirements, planeness shall be accomplished by capping in accordance
with Practice C617, or by lapping, or by grinding. It is not prohibited to repair aggregate popouts that occur at the ends of
specimens, provided the total area of popouts does not exceed 10 % of the specimen area and the repairs are made before capping
or grinding is completed (Note 2). Planeness will be considered within tolerance when a 0.05 mm 0.05 mm [0.002 in.] feeler gauge
will not pass between the specimen surface and a straight edge held against the surface.
NOTE 2—Repairs may be made by epoxying the dislodged aggregate back in place or by filling the void with capping material and allowing adequate
time for it to harden.
5.4 Measure the diameter of the test specimen by caliper to the nearest 0
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