Standard Practices for Preparing Rock Core Specimens and Determining Dimensional and Shape Tolerances

SCOPE
1.1 This practice specifies procedures for determining the length and diameter of rock core specimens and the conformance of the dimensions with established standards.
1.2 Rock is a complex engineering material which can vary greatly as a function of lithology, stress history, weathering, and other natural geologic processes. As such, it is not always possible to obtain or prepare rock core specimens which satisfy the desirable criteria given in this practice. Most commonly, this situation presents itself with weaker, more porous, and poorly cemented rock types and rock types containing significant structural features. For these and other rock types which are difficult to prepare, all reasonable efforts shall be made to prepare a sample in accordance with this practice. However, when it has been determined by trial that this is not possible, prepare the rock specimen to the highest standard practicable and consider this to be the best effort and report it as such, with all appropriate size and dimensional measurements reported as in Section 6.
1.3 This practice also prescribes tolerance checks on the straightness of the elements on the cylindrical surface, the flatness of the end bearing surfaces, and the perpendicularity of the end surfaces with the axis of the core.
1.4 The requirement for specifying the moisture condition of the test specimen at the time of the test is also stated.
1.5 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
1.6 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 and health practices and determine the applicability of regulatory limitations prior to use.
1.7 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgement. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word "standard" in the title of this document means only that the document has been approved through the ASTM consensus process.

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09-Jun-2001
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ASTM D4543-85(1991)e1 - Standard Practices for Preparing Rock Core Specimens and Determining Dimensional and Shape Tolerances
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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: D 4543 – 85 (Reapproved 1991)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Practice for
Preparing Rock Core Specimens and Determining
Dimensional and Shape Tolerances
This standard is issued under the fixed designation D 4543; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Section 7 was added editorially in December 1991.
1. Scope D 2113 Method for Diamond Core Drilling for Site Inves-
tigation
1.1 This practice specifies procedures for determining the
D 2664 Test Method for Triaxial Compressive Strength of
length and diameter of rock core specimens and the conform-
Undrained Rock Core Specimens without Pore Pressure
ance of the dimensions with established standards.
Measurements
1.2 Rock is a complex engineering material which can vary
D 2936 Test Method for Direct Tensile Strength of Intact
greatly as a function of lithology, stress history, weathering,
Rock Core Specimens
and other natural geologic processes. As such, it is not always
D 2938 Test Method for Unconfined Compressive Strength
possible to obtain or prepare rock core specimens which satisfy
of Intact Rock Core Specimens
the desirable criteria given in this practice. Most commonly,
D 3148 Test Method for Elastic Moduli of Intact Rock Core
this situation presents itself with weaker, more porous, and
Specimens in Uniaxial Compression
poorly cemented rock types and rock types containing signifi-
D 3967 Test Method for Splitting Tensile Strength of Intact
cant structural features. For these and other rock types which
Rock Core Specimens
are difficult to prepare, all reasonable efforts shall be made to
D 4341 Test Method for Creep of Cylindrical Hard Rock
prepare a sample in accordance with this practice. However,
Core Specimens in Uniaxial Compression
when it has been determined by trial that this is not possible,
D 4405 Test Method for Creep of Cylindrical Soft Rock
prepare the rock specimen to the highest standard practicable
Core Specimens in Uniaxial Compression
and consider this to be the best effort and report it as such, with
D 4406 Test Method for Creep of Cylindrical Rock Core
all appropriate size and dimensional measurements reported as
Specimens in Triaxial Compression
in Section 6.
1.3 This practice also prescribes tolerance checks on the
3. Significance and Use
straightness of the elements on the cylindrical surface, the
3.1 The dimensional, shape, and surface tolerances of rock
flatness of the end bearing surfaces, and the perpendicularity of
core specimens are important for determining rock properties
the end surfaces with the axis of the core.
of intact specimens. Dimensional and surface tolerance checks
1.4 The requirement for specifying the moisture condition
are required in the test methods listed in 2.1. To simplify test
of the test specimen at the time of the test is also stated.
procedures in laboratories, the parts of those procedures that
1.5 The values stated in inch-pound units are to be regarded
are common to the test methods are given in this standard.
as the standard.
1.6 This standard does not purport to address all of the
4. Specimens
safety problems, if any, associated with its use. It is the
4.1 Test specimens shall be right circular cylinders within
responsibility of the user of this standard to consult and
the tolerances specified herein.
establish appropriate safety and health practices and deter-
4.2 The specimen shall have a length-to-diameter ratio
mine the applicability of regulatory limitations prior to use.
(L/D) of 2.0 to 2.5 and a diameter of not less than 1 ⁄8 in. (47
2. Referenced Documents mm).
2.1 ASTM Standards:
NOTE 1—It is desirable that the diameter of rock test specimens be at
C 617 Practice for Capping Cylindrical Concrete Speci- least ten times the diameter of the largest mineral grain. For weak rock
types which behave more like soil (for example, weakly cemented
mens
sandstone), the specimen diameter should be at least six times the
maximum particle diameter. It is considered that the specified minimum
specimen diameter of approximately 1 ⁄8 in. (47 mm) will satisfy this
This practice is under the jurisdiction of ASTM Committee D-18 on Soil and
Rock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.
Current edition approved Nov. 29, 1985. Published January 1986.
2 3
Annual Book of ASTM Standards, Vol 04.02. Annual Book of ASTM Standards, Vol 04.08.
D 4543
criterion in the majority of cases. When cores of diameter smaller than the
specimen does not meet the required tolerance for straightness
specified minimum must be tested because of the unavailability of larger
of the elements. The flat test surface on which the specimen is
diameter core, as is often the case in the mining industry, suitable notation
rolled shall not depart from a plane by more than 0.0005 in. (15
of this fact shall be made in the report.
μm).
5.1.2 Procedure B—Place the cylindrical surface of the
specimen on a V-block that is laid flat on a support surface. The
V-block shall be machinist quality with all bearing faces
surface ground and with a 90° included angle. Maintain the
support surface and all bearing surfaces on the V-block flat and
smooth to within 0.0005 in. (15 μm). The length of the V-block
shall be sufficient that the specimen will not project over its
ends during movement.
5.1.2.1 Place a dial gage in contact with the top of the
specimen, as shown in Fig. 1, and observe the dial reading as
the specimen is moved from one end of the V-block to the other
along a straight line, without rotation. The sensitivity of the
dial gage shall be at least 0.001 in. (25 μm). The measurement
contact tip of the dial gage shall be round in shape.
5.1.2.2 Record the maximum and minimum readings on the
dial gage and calculate the difference, D . If the dial gage
traverses a natural cavity in the rock, readings in this region
should not be included in the determination of D . Repeat the
FIG. 1 Assembly for Determining the Straightness of Elements
same operations by rotating the specimen for every 120°, and
on the Cylindrical Surface
obtain the differences D and D . The maximum value of
120 240
these three differences shall be less than 0.020 in. (0.50 mm).
5.2 Check the flatness tolerance by a setup similar to that for
the cylindrical surface (Fig. 2) except that the dial gage shall be
mounted near the end of the V-block.
5.2.1 Move the mounting pad horizontally so that the dial
gage runs across a diameter of the specimen end surface. Take
care to make sure that one end of the mounting pad maintains
intimate contact with the end surface of the V-block during
movement. A dial gage sensitive to 0.0001 in. (2.5 μm) is
required for measurements on the end surfaces.
5.2.2 Record the dial gage readings every ⁄8 in. (3 mm)
across the diameter. These readings may be recorded in tabular
FIG. 2 Assembly for Determining the Flatness and
form, or to simplify the procedure, they may be plotted directly
Perpendicularity of End Surfaces to the Specimen Axis
on a graph as shown for End 1, Diameter 1, in Fig. 3. Data
recording is also simplified if the dial gage is set to zero when
4.3 The sides of the specimen shall be generally smooth and
it is in contact with the center of the end face.
free of abrupt irregularities, with all the elements straight to
5.2.2.1 Plot the readings and draw a smooth curve through
within 0.020 in. (0.50 mm) over the full length of the specimen,
the points to represent the surface profile along the specified
as determined by 5.1.
diameterical plane, as shown for End 1, Diameter 1, in Fig. 3.
4.4 The ends of the specimen shall be cut parallel to each
Do not plot dial gage readings taken when the gage tip drops
other and at right angles to the longitudinal axis. The end
into a natural cavity in the rock. The flatness tolerance is met
surfaces shall be surface ground or lapped flat to a tolerance not
when the smooth curve so determined does not depart from a
to exceed 0.001 in. (25 μm), as determined by 5.2.
visual best-fit straight line by more than 0.001 in. (25 μm).
...

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