ASTM D4543-19

Standard Practices for Preparing Rock Core as Cylindrical Test Specimens and Verifying Conformance to Dimensional and Shape Tolerances

SIGNIFICANCE AND USE
4.1 The dimensional, shape, and surface tolerances of rock core test specimens are important for determining rock properties of intact specimens. This is especially true for strong rocks, greater than 7250 psi (50 MPa) and for rock specimens that will be tested in stiff testing load frames without a spherical seat where non-uniform loading could occur. Dimensional and surface tolerance checks are required in the test methods listed in Section 2.1. To simplify test procedures in laboratories, the parts of those procedures that are common to the test methods in Section 2.1 are given in this standard.  
4.2 This procedure is applicable to all the standards listed in Section 2.1; however, specimens for Test Method D2936 do not need to be machined or to meet the specified tolerances for flatness and parallelism.  
4.3 The moisture condition of the specimen at the time of the sample preparation can have a significant effect upon the strength and deformation characteristics of the rock. Good practice generally dictates that laboratory tests be made upon a specimens’ representative of field conditions. Thus, it follows that the field moisture condition of the specimen should be preserved until the time of the test. In some instances, however, there may be reasons for testing specimens at other moisture contents, from saturation to dry. In any case, the moisture content of the test specimen should be tailored to the problem at hand.  
Note 3: Discussions on moisture content are common in many rock testing standards but professional judgement will be needed to both handle and report this issue. For example, when obtaining the samples or preparing the specimens, water or some other cooling agent may be required or used. Therefore, the moisture in the specimen or samples may not be what it was in situ; this applies to both water chemistry and quantity of fluids. This issue should be addressed, and a plan put in place for each step from the sampling to the testing phase in a ...
SCOPE
1.1 These practices specify procedures for preparing rock test specimen of rock core from drill core obtained in the field or from block samples for strength and deformation testing and for determining the conformance of the test specimen dimensions with tolerances established by this practice. Cubical, rectangular, or other shapes are not covered by this practice. However, some of the information contained within this practice and in standard Test Method C170 may still be of use to preparing other test specimen shapes.  
1.2 Rock is a complex engineering material that can vary greatly as a function of lithology, stress history, weathering, moisture content and chemistry, and other natural geologic processes. As such, it is not always possible to obtain or prepare rock core specimens that satisfy the desirable tolerances given in this practice. Most commonly, this situation presents itself with weaker, more porous, and poorly cemented rock types and rock types containing significant or weak (or both) structural features. For rock types which are difficult to prepare, all reasonable efforts should be made to prepare a specimen in accordance with this practice and for the intended test procedure. However, when it has been determined by trial and error that this is not possible, prepare the rock specimen to the closest tolerances practicable and consider this to be the best effort (Note 1) and report it as such and if allowable or necessary for the intended test, capping the ends of the specimen as discussed in this practice is permitted.
Note 1: Best effort in surface preparation refers to the use of a well-maintained, suitable surface grinder, lathe or lapping machine and any required ancillary equipment are utilized by an experienced operator and in which a reasonable number of attempts has been made to meet the tolerances required in this procedure.  
1.3 This practices covers some, but not all of the curatorial iss...

General Information

• Status: Published
• Publication Date: 31-May-2019
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.12 - Rock Mechanics

Relations

• Refers: ASTM D4753-24 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-Feb-2024
• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM D2936-20 - Standard Test Method for Direct Tensile Strength of Intact Rock Core Specimens
• Effective Date: 01-Jan-2020
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM D2216-19 - Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• Effective Date: 01-Mar-2019
• Refers: ASTM D7070-16 - Standard Test Methods for Creep of Rock Core Under Constant Stress and Temperature
• Effective Date: 01-Nov-2016
• Refers: ASTM D4753-15 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-May-2015
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM D7012-14 - Standard Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures
• Effective Date: 01-May-2014
• Refers: ASTM D7012-13 - Standard Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures
• Effective Date: 15-Nov-2013
• Refers: ASTM D3740-12a - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-May-2012
• Refers: ASTM D3740-12 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2012
• Refers: ASTM D653-11 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Sep-2011
• Refers: ASTM D3740-11 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Sep-2011
• Refers: ASTM D2216-10 - Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• Effective Date: 01-Jul-2010

Overview

ASTM D4543-19: Standard Practices for Preparing Rock Core as Cylindrical Test Specimens and Verifying Conformance to Dimensional and Shape Tolerances is a key ASTM International standard used in geotechnical and rock mechanics laboratories worldwide. This document provides unified procedures for preparing cylindrical test specimens from rock cores, ensuring that samples meet strict dimensional, shape, and surface tolerances for accurate testing of rock properties. Adherence to ASTM D4543-19 promotes reliable and comparable results in laboratory strength and deformation tests on rock materials.

Key Topics

• Specimen Preparation

  • Procedures for shaping rock core into right circular cylinders suitable for various strength and deformation tests.
  • Detailed tolerances for length-to-diameter ratio, straightness, flatness, and parallelism of specimen ends.
  • Handling specimens from both field-drilled cores and block samples.

• Dimensional and Shape Tolerance Verification

  • Methods to verify specimen features such as length, diameter, side straightness, and end surfaces.
  • Use of apparatus such as surface grinders, V-blocks, dial gages, and feeler gages for quality assurance checks.

• Moisture Content Considerations

  • Importance of preserving field moisture conditions or tailoring specimen moisture to suit testing requirements.
  • Procedures to mitigate effects of sample preparation fluids on rock properties.

• Applicability and Limitations

  • Guidance for preparing both strong and weak rocks, including strategies when ideal tolerances cannot be met due to lithological or structural complexities.
  • Use of capping materials when surface preparation is not possible, within specified limitations.

• Reporting and Best Practices

  • Documentation of preparation process, deviation from standard tolerances, and specimen condition.
  • Emphasis on professional judgement, safety, and quality control in all laboratory operations.

Applications

ASTM D4543-19 is essential for laboratories and engineers involved in:

• Rock Mechanics Testing: Standardizes sample preparation for tests measuring compressive strength, elastic moduli, and deformation properties of intact rock.
• Geotechnical Site Investigations: Enables robust comparison of rock properties by enforcing consistent sample geometries and tolerances.
• Construction Materials Analysis: Supports quality assurance for selecting, processing, and documenting rock materials for civil engineering and mining projects.
• Research and Development: Ensures data reliability and reproducibility when developing new test methods or analyzing rock behavior under different stresses and moisture conditions.
• Global Collaboration and Compliance: Facilitates international cooperation and compliance by following a harmonized standard recognized by the World Trade Organization Technical Barriers to Trade (TBT) principles.

Related Standards

ASTM D4543-19 is referenced by and works in conjunction with several other ASTM standards, including:

• ASTM D7012 - Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens
• ASTM D2113 - Practice for Rock Core Drilling and Sampling of Rock for Site Exploration
• ASTM C170 - Test Method for Compressive Strength of Dimension Stone
• ASTM D2216 - Methods for Laboratory Determination of Water Content of Soil and Rock
• ASTM D653 - Terminology Relating to Soil, Rock, and Contained Fluids
• ASTM D3740 - Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock
• ASTM D4753 - Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses
• ASTM C617 - Practice for Capping Cylindrical Concrete Specimens

By following ASTM D4543-19, laboratories and professionals ensure that rock test specimens deliver precise, consistent, and internationally recognized results, forming a foundation for all high-quality rock testing programs.

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: D4543 − 19
Standard Practices for
Preparing Rock Core as Cylindrical Test Specimens and
Verifying Conformance to Dimensional and Shape
Tolerances
This standard is issued under the fixed designation D4543; 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* refertoPracticesD5079andtothespecificteststandardsin2.1
for which the specimens are being prepared.
1.1 These practices specify procedures for preparing rock
test specimen of rock core from drill core obtained in the field 1.4 This practice also prescribes tolerance checks on the
orfromblocksamplesforstrengthanddeformationtestingand length-to-diameter ratio, straightness of the elements on the
for determining the conformance of the test specimen dimen- cylindricalsurface,theflatnessoftheendbearingsurfaces,and
sions with tolerances established by this practice. Cubical, the perpendicularity of the end surfaces with the axis of the
rectangular, or other shapes are not covered by this practice. core.
However, some of the information contained within this
NOTE 2—This practice does not purport to cover all the issues that will
practice and in standard Test Method C170 may still be of use
or could be encountered that may control the quality of the specimen
to preparing other test specimen shapes.
preparation required. Each laboratory may have their own issues, espe-
cially for different compression load frames or rock types. For example,
1.2 Rock is a complex engineering material that can vary
stiff testing frames versus traditional load frames and loading platens with
greatly as a function of lithology, stress history, weathering,
or without spherical seating. Specimens for a stiff testing load frame with
moisture content and chemistry, and other natural geologic nosphericalseatmayneedtohavemorestringentrequirementsdepending
on the type of rock being tested. This procedure has tried to show the
processes. As such, it is not always possible to obtain or
methods and QA that may be involved while keeping in mind those
prepare rock core specimens that satisfy the desirable toler-
materials that are difficult to work with and for which the specimens will
ances given in this practice. Most commonly, this situation
still be suitable to be tested. The available literature and input on this
presents itself with weaker, more porous, and poorly cemented
subject from D18.12 members were considered as much as possible for
rock types and rock types containing significant or weak (or this standard.
both) structural features. For rock types which are difficult to
1.5 The requirement for specifying the moisture condition
prepare, all reasonable efforts should be made to prepare a
and volume of the test specimen is also stated. However, the
specimen in accordance with this practice and for the intended
requirements in the specific test standards in 2.1 should be
test procedure. However, when it has been determined by trial
followed too.
and error that this is not possible, prepare the rock specimen to
1.6 All observed and calculated values shall conform to the
the closest tolerances practicable and consider this to be the
guidelines for significant digits and rounding established in
best effort (Note 1) and report it as such and if allowable or
Practice D6026, unless superseded by this standard.
necessary for the intended test, capping the ends of the
1.6.1 The practices/procedures used to specify how data are
specimen as discussed in this practice is permitted.
collected/recorded and calculated in this standard are regarded
NOTE 1—Best effort in surface preparation refers to the use of a
as the industry standard. In addition, they are representative of
well-maintained, suitable surface grinder, lathe or lapping machine and
the significant digits that generally should be retained. The
any required ancillary equipment are utilized by an experienced operator
proceduresuseddonotconsidermaterialvariation,purposefor
and in which a reasonable number of attempts has been made to meet the
obtaining the data, special purpose studies, or any consider-
tolerances required in this procedure.
ations for the user’s objectives; and it is common practice to
1.3 This practices covers some, but not all of the curatorial
increase or reduce significant digits of reported data to be
issues that should be implemented. For curatorial issues that
commensuratewiththeseconsiderations.Itisbeyondthescope
should be followed before and during specimen preparation
1 2
ThesepracticesareunderthejurisdictionofASTMCommitteeD18onSoiland NeedlessStringencyinSamplePreparationStandardsforLaboratoryTestingof
RockandarethedirectresponsibilityofSubcommitteeD18.12onRockMechanics. Weak Rocks, P.J.N. Pells (Coffey & Partners pty Ltd, North Ryde) | M.J. Ferry
CurrenteditionapprovedJune1,2019.PublishedJuly2019.Originallyapproved (Postgraduate Scholar, University of Sydney), International Society for Rock
ɛ1
in 1985. Last previous edition approved in 2008 as D4543–08 . DOI: 10.1520/ Mechanics Source 5th ISRM Congress, 10-15April, Melbourne,Australia Publica-
D4543-19. tion Date 1983.
*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
D4543 − 19
of this standard to consider significant digits used in analysis C617Practice for Capping Cylindrical Concrete Specimens
methods for engineering design. D653Terminology Relating to Soil, Rock, and Contained
Fluids
1.7 Units—The values stated in inch-pound units are to be
D2113Practice for Rock Core Drilling and Sampling of
regarded as standard. The values given in parentheses are
Rock for Site Exploration
mathematical conversions to SI units that are provided for
D2216Test Methods for Laboratory Determination ofWater
information only and are not considered standard. Add if
(Moisture) Content of Soil and Rock by Mass
appropriate, “Reporting of test results in units other than
D2936Test Method for Direct Tensile Strength of Intact
inch-pound shall not be regarded as nonconformance with this
Rock Core Specimens (Withdrawn 2017)
standard.”
D3740Practice for Minimum Requirements for Agencies
1.7.1 The slug unit of mass is typically not used in com-
Engaged in Testing and/or Inspection of Soil and Rock as
mercial practice; that is, density, balances, and so on.
Used in Engineering Design and Construction
Therefore, the standard unit for mass in this standard is either
D4753Guide for Evaluating, Selecting, and Specifying Bal-
kilogram (kg) or gram (g) or both. Also, the equivalent
ances and Standard Masses for Use in Soil, Rock, and
inch-pound unit (slug) is not given/presented in parentheses.
Construction Materials Testing
1.7.2 It is common practice in the engineering/construction
D5079Practices for Preserving andTransporting Rock Core
profession to concurrently use pounds to represent both a unit
Samples (Withdrawn 2017)
of mass (lbm) and of force (lbf). This practice implicitly
D6026Practice for Using Significant Digits in Geotechnical
combines two separate systems of units; the absolute and the
Data
gravitational systems. It is scientifically undesirable to com-
D7012Test Methods for Compressive Strength and Elastic
bine the use of two separate sets of inch-pound units within a
Moduli of Intact Rock Core Specimens under Varying
single standard. As stated, this standard includes the gravita-
States of Stress and Temperatures
tional system of inch-pound units and does not use/present the
D7070Test Methods for Creep of Rock Core Under Con-
slug unit for mass. However, the use of balances or scales
3 stant Stress and Temperature
recordingpoundsofmass(lbm)orrecordingdensityinlbm/ft
shall not be regarded as nonconformance with this standard.
3. Terminology
1.8 This standard does not purport to address all of the
3.1 Definitions:
safety concerns, if any, associated with its use. It is the
3.1.1 Fordefinitionsofcommontechnicaltermsusedinthis
responsibility of the user of this standard to establish appro-
standard, refer to Terminology D653
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Significance and Use
1.9 These practices offer a set of instructions for performing
one or more specific operations. This document cannot replace
4.1 The dimensional, shape, and surface tolerances of rock
education or experience and should be used in conjunction
core test specimens are important for determining rock prop-
with professional judgement. Not all aspects of this practice
erties of intact specimens. This is especially true for strong
may be applicable in all circumstances. This ASTM standard is
rocks, greater than 7250 psi (50 MPa) and for rock specimens
not intended to represent or replace the standard of care by
that will be tested in stiff testing load frames without a
which the adequacy of a given professional service must be
spherical seat where non-uniform loading could occur. Dimen-
judged, nor should this document be applied without consid-
sional and surface tolerance checks are required in the test
eration of a project’s many unique aspects. The word “stan-
methods listed in Section 2.1. To simplify test procedures in
dard” in the title of this document means only that the
laboratories, the parts of those procedures that are common to
document has been approved through the ASTM consensus
the test methods in Section 2.1 are given in this standard.
process.
4.2 Thisprocedureisapplicabletoallthestandardslistedin
1.10 This international standard was developed in accor-
Section 2.1; however, specimens for Test Method D2936 do
dance with internationally recognized principles on standard-
not need to be machined or to meet the specified tolerances for
ization established in the Decision on Principles for the
flatness and parallelism.
Development of International Standards, Guides and Recom-
4.3 The moisture condition of the specimen at the time of
mendations issued by the World Trade Organization Technical
the sample preparation can have a significant effect upon the
Barriers to Trade (TBT) Committee.
strength and deformation characteristics of the rock. Good
2. Referenced Documents practice generally dictates that laboratory tests be made upon a
specimens’ representative of field conditions. Thus, it follows
2.1 ASTM Standards:
that the field moisture condition of the specimen should be
C170Test Method for Compressive Strength of Dimension
preserveduntilthetimeofthetest.Insomeinstances,however,
Stone
there may be reasons for testing specimens at other moisture
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
D4543 − 19
contents, from saturation to dry. In any case, the moisture
content of the test specimen should be tailored to the problem
at hand.
NOTE 3—Discussions on moisture content are common in many rock
testingstandardsbutprofessionaljudgementwillbeneededtobothhandle
and report this issue. For example, when obtaining the samples or
preparing the specimens, water or some other cooling agent may be
required or used.Therefore, the moisture in the specimen or samples may
notbewhatitwasinsitu;thisappliestobothwaterchemistryandquantity
of fluids. This issue should be addressed, and a plan put in place for each
step from the sampling to the testing phase in a manner that records/
reports what steps were advised to successfully prepare testable samples.
FIG. 2 Assembly for Determining the Flatness and Perpendicu-
Usually a compromise between preserving in-situ conditions, costs,
larity of End Surfaces to the Specimen Axis (FP1)
conditions outside the control of the laboratory and obtaining testable
specimens is required. For example, loss of moisture that leads to the
samples or specimens falling apart may be of greater concern than testing
grade, certified, granite blocks are commonly used for support
with in situ water or at the in situ water content or both.
surfaces because they do not dent or rust. However, other
4.4 Excess moisture will affect the adhesion of resistance
materials may be used if they meet the criteria of the
strain gages, if used, and the accuracy of their performance.
procedure. The area of the support surface will depend on the
Adhesives used to bond the rock to steel end caps and fixtures
sizeofspecimentobeprepared;however,a12in.×12in.(300
for attaching specimens to actuators and crosshead of the load
mm × 300 mm) area will be sufficient for most applications.
frame in the direct tension test (D2936) will also be affected
5.2 V-block (conformance tests)—The V-block (Figs. 1 and
adversely by excess moisture.
3) shall be machinist quality with all bearing faces surfaces
NOTE 4—The quality of the result produced by these practices is
groundflat,smoothtowithin0.0005in.(13µm)andwitha90°
dependent upon the competence of the personnel performing it and the
included angle. The V-block shall have some means of secur-
suitability of the equipment and facilities used. Agencies that meet the
criteria of Practice D3740 are generally considered capable of competent ing the specimen firmly in the V-block. The dimensions of the
and objective testing and sampling. Users of these practices are cautioned
V-block must be such that it does not physically interfere with
that compliance with Practice D3740 does not in itself assure reliable
the displacement gage readings and suited for the size of
results. Reliable results depend on many factors; Practice D3740 provides
specimen to be handled.
a means of evaluating some of those factors.
5.3 Displacement Gage Assembly (Figs. 1 and 2):
5. Apparatus
5.3.1 Dial or Electronic (Contact or Non-contact) Displace-
5.1 Support Surface—A flat test surface which shall not ment Gage—The sensitivity of the displacement gage shall be
depart from a plane by more than 0.0005 in. (0.013 mm) or at least 0.001 in. (0.02 mm) for measurement of cylindrical
meets ISO 9001 Certification. It shall have a large enough area surfaces. The measurement contact tip of the displacement
such that the cylindrical surface of a rock core test specimen gage should be round.Adisplacement gage readable to 0.0001
may be rolled and a V-block end of a rock core test specimen, in. (0.002 mm) is advised for measurements on the end
ordisplacementgageassemblycanbeplaced(Figs.1and2)to surfaces.
perform the required tolerances measurements. Machinist 5.3.2 Dial or Electronic (Contact or Optic) Displacement
Gage Stand—A stand with a base and vertically mounted rod
with an adjustable gage holder to support the gage on the flat
surface at the proper height for the specimen and to take
measurements normal to the flat surface. The side of the base
can be machined flat so that it may be used as a straight edge
for taking measurements as shown in Fig. 1 and Fig. 2 and
described in 9.1 and 9.2. See Note 11 for more useful
information.
5.4 Feeler Gage Set—25 or 26 leaf/blade set; 3 in. (76 mm)
long by ⁄2 in. (13 mm) wide, and thicknesses beginning at
0.0015 in. (0.04 mm) and ending at 0.025 in. (0.64 mm).
5.5 Surface Grinder—Any manual or automatic machinist’s
gradesurfacegrinderequippedwithagrindingwheelsuitedfor
the type and size of specimen, a magnetic flat surface and a
V-block (5.6) to hold one or more specimens during the
grinding process is suitable. The apparatus is also equipped to
apply appropriate cooling and cutting agents (if needed) at the
cutting surface to cool the grinding wheel surface and remove
any cuttings.
FIG. 1 Basic Dial Gage Setup for Determining the Straightness of
Elements Along the Cylindrical Surface (S2) NOTE 5—A commonly available apparatus and method is presented in
D4543 − 19
FIG. 3 One example of Holding Jig for Surface Grinder that can be Rotated and Grind Both Ends of up to Four Specimens (The adja-
cent short core is used as a spacer to fill unused specimen slot and yellow on top of specimen is placed prior to grinding for showing
where grinding is occurring as the surface grinding progresses. Once lapping of the visible specimen end is completed the top half of
the jig is unbolted and the section rotated so the opposing end of the specimen is now facing up and can be lapped as well.)
the sections provided here. Any other specialty or expensive type
suitable for the material to be cut, with a movable platform for
equipmentormethodsorcombinationthereofthatcanshapetherockcore
holding and feeding the core specimen, perpendicular to the
specimen into a specimen and meet the specification is acceptable.
core axis and feeding the specimen into the cutting surface of
NOTE 6—Surface grinders with greater mass is preferred because they
theblade.Themovableplatformmaybeamanualorautomatic
have a greater resistance against vibration and will therefore produce a
more uniform surface. Grinding wheels should be true and balanced.
feed device. A GFI (Ground Fault Interrupt) for electrical
Some surface grinders have wheel hubs/flanges that did not have
powered saws is advised.The apparatus should be equipped to
balancing systems however this could be added later using aluminum
safelyapplyappropriatecoolingagents(ifneeded)tothecutter
leaves.
to cool the blade and remove any cuttings and, if required,
5.6 V-Block, or Other Similar Holding Device (Grinder
retained in a settling tank setup for disposal.
Accessory)—Ametal V-block of sufficient size for holding the
5.8 For Drilling Block Samples:
rock specimen in the surface grinder, with or without a
magnetic chuck and is configured so that the specimen can be
5.8.1 Atleasta10-horsepower(750kgf-mpersecond)drill,
rotated to grind both ends and without losing any alignment
with a GFI (Ground Fault Interrupt) for electrical powered
with the grinder tolerances that would affect the grinding
drills is recommended.
results on the specimen. See showing one example of V-block
5.8.2 Drill can be hand held but some type of rigid platform
designed for up to four specimens on a magnetic chuck.
is preferred, and side straightness may not be met and could
5.7 Lapidary/Trim Saw—Apower saw of adequate size and then involve extra effort such as machining of sides of the
horse power equipped with a circular diamond saw blade sample or specimen.
D4543 − 19
5.8.3 Drill bit can be advanced manually or automatically. 7.2 The specimen shall have a length-to-diameter ratio
5.8.4 A thin walled diamond core barrel is typically used. (L/D) of 2.0 to 2.5 and a minimum diameter 1- ⁄8 in. (47 mm)
However, if needed, most drilling supply companies can build or as directed by the client.
a short, double or triple tube core barrel that may be useful for
NOTE 7—The larger the internal friction angle of a specimen the more
certain rock types too.
important it will be to have larger L/D ratios so that the specimen can
5.8.5 A swivel and adaptors for hooking up to the drill to
potentiallydevelopatrueshearplanethatdoesnotpassthrougheitherend
of the specimen or is not altered by the specimen size.
supply a fluid to cool the cutting surface and remove any
NOTE 8—It is important to determine what type of test specimen and
cuttings.
test apparatus will be used before starting the specimen preparation
5.9 (Optional) Lapper. process or the required end product may not be obtained.
NOTE 9—It is desirable that the diameter of rock test specimens be at
5.10 (Optional) Machinist Shaper.
least ten times the diameter of the largest discrete mineral grain, particle
or crystalline. For weak rock types which behave more like soil (for
5.11 Cooling or Cutting Agents—This is typically portable
example,poorlycementedsandstone),thespecimendiametershouldbeat
water or house air but may be some other liquid or gas for
least six times the maximum particle diameter. It is considered that the
special circumstances. Whatever cooling or cutting agent is 7
specified minimum specimen diameter of approximately 1-
⁄8 in. (47 mm)
used it must be suitable for the specimen preparation process willsatisfythiscriterioninthemajorityofcases.Whencoreswithsmaller
diameters than the specified minimum must be tested because larger
such that it leaves a specimen’s strength properties unaffected.
diameter cores are unavailable or impractical use of large drilling
Forexample,sedimentaryrocksoriginallydepositedinasaline
equipment (as is often the case in the mining industry), costs, or both, are
environment may be affected if subjected to fresh water.
prohibitive, a suitable notation of this fact shall be made in the report.
5.12 Machinist Calipers, or similar device, with vernier,
7.3 The cylindrical surfaces of the specimen shall be gen-
digital, or dial readouts readable to 0.001 in. (0.025 mm) and
erally smooth and free of abrupt irregularities that are not part
large enough for the size of the specimens being measured.
of the rock natural fabric, that is, voids or vugs, with all the
elements straight to within 0.020 in. (0.50 mm) over the full
5.13 Scale or Balance, of adequate size and capacity to
length of the specimen, as determined by 9.1, procedure S1 or
measure the mass of the specimen after preparation is com-
S2.
pleted to the nearest 1 gram. All balances must meet the
requirements of Guide D4753 and this section. A Class GP1
7.4 The ends of the specimen shall be cut parallel to each
balance of 0.01 g readability is required for specimens having
other and at right angles to the longitudinal axis. The end
a mass of up to 200 g (excluding mass of specimen container)
surfacesshallbesurfacegroundorlappedflattoatolerancenot
and a Class GP2 balance of 0.1 g readability is required for
to exceed 0.001 in. (25 µm), as determined by 9.2 and to make
specimens having a mass over 200 g. If desired, a Class GP1
the two ends more parallel to each other.
balance may be used for specimens exceeding 200 g providing
7.5 The use of capping materials or end surface treatments
the specimen size is within the capacity of the balance.
other than the grinding, lathe, and lapping specified herein is
However,thebalanceusedmaybecontrolledbythenumberof
not permitted, except as noted in 7.6.
significant digits needed (see 1.10).
7.6 There are some rock types with physical characteristics
5.14 Miscellaneous Tools, machinist scribe, rubber mallet,
or low strengths which preclude preparing specimens to the
safetyglasses,hearingprotection,containersorplasticbagsfor
flatness tolerance specified in 7.4, even with the best effort
curatorial control and indelible markers.
(Note 9). In these instances, first cut the core specimen to
length,thenapplyendcapstotheendsurfacesofthespecimen.
6. Samples
7.7 The specifications for the capping compound, capping
6.1 Samples for preparing specimens can be either drill
plates, and alignment devices and the procedure for capping
cores obtained directly from the in situ rock (D2113)or
weak rock core specimens shall be the same as those estab-
obtained from block samples cored in the field or in the
lished for compression testing of concrete in Practice C617;
laboratory.
however, melted sulfur capping compounds are not permitted
6.2 Samplesshouldbeselectedorobtained(orboth)tomeet
becauseofthepossibledetrimentaleffectsofthehightempera-
the objectives of the specific standard listed in 2.1 and the test
ture from such capping compounds on the rock. Dental plaster
program and any requirements related to anisotropic
and high strength gypsum cements are commonly used but
properties, moisture, and alike, of the in situ material that are
other materials may be acceptable or better suited for the rock
relevant to the intended use.
types being prepared.
6.3 Block samples must be provided which are clearly 7.8 The ends of the specimen shall not depart from perpen-
marked and if needed have appropriate measurements taken
dicularity to the axis of the specimen by more than 0.25° as
during sample acquisition to identify the orientation and or
determined in Section 9.
locationofanygeologiccharacteristicsthatmightbeimportant
7.9 The parallelism tolerance is the maximum angular
for coring samples from the block sample.
differe
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