1、Designation: D 4543 07Standard Practices forPreparing Rock Core as Cylindrical Test Specimens andVerifying Conformance to Dimensional and ShapeTolerances1This standard is issued under the fixed designation D 4543; the number immediately following the designation indicates the year oforiginal adoptio
2、n or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice specifies procedures for laboratory rockcore test specimen
3、preparation of rock core from drill core andblock samples for strength and deformation testing and fordetermining the conformance of the test specimen dimensionswith tolerances established by this practice. Cubical, rectangu-lar, or other shapes are not covered by this practice. However,some of the
4、information contained with in this practice and instandard Test Method C 170 may still be of use to preparingother test specimen shapes.1.2 Rock is a complex engineering material that can varygreatly as a function of lithology, stress history, weathering,moisture content and chemistry, and other nat
5、ural geologicprocesses. As such, it is not always possible to obtain orprepare rock core specimens that satisfy the desirable toler-ances given in this practice. Most commonly, this situationpresents itself with weaker, more porous, and poorly cementedrock types and rock types containing significant
6、 and/or weakstructural features. For these and other rock types which aredifficult to prepare, all reasonable efforts shall be made toprepare a specimen in accordance with this practice and for theintended test procedure. However, when it has been determinedby trial that this is not possible, prepar
7、e the rock specimen tothe closest tolerances practicable and consider this to be thebest effort (Note 1) and report it as such and if allowable ornecessary for the intended test, capping the ends of thespecimen as discussed in this practice is permitted.NOTE 1Best effort in surface preparation refer
8、s to the use of awell-maintained surface grinder, lathe or lapping machine by an experi-enced operator in which a reasonable number of attempts has been madeto meet the tolerances required in this procedure.1.3 This practices covers some, but not all of the curatorialissues that should be implemente
9、d. For curatorial issues thatshould be followed before and during specimen preparationrefer to Practices D 5079 and to the specific test standards insection 2.1 for which the specimens are being prepared.1.4 This practice also prescribes tolerance checks on thelength-to-diameter ratio, straightness
10、of the elements on thecylindrical surface, the flatness of the end bearing surfaces, andthe perpendicularity of the end surfaces with the axis of thecore.1.5 The requirement for specifying the moisture conditionof the test specimen is also stated. However, the requirementsin the specific test standa
11、rds in section 2.1 should be followedtoo.1.6 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D 6026, unless superseded by this standard.1.6.1 The practices /procedures used to specify how data arecollected/recorded and calc
12、ulated in this standard are regardedas the industry standard. In addition, they are representative ofthe significant digits that generally should be retained. Theprocedures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the
13、 users objectives; and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations. It is beyond the scopeof this standard to consider significant digits used in analysismethods for engineering design.1.7 UnitsThe dimensional values stat
14、ed in either inch-pound units or SI units are to be regarded as standard, such as4 to 12 in. or 100 to 300 mm. The values stated in each systemmay not be exact equivalents; therefore, each system shall beused independently of the other. Combining values from the1These practices are under the jurisdi
15、ction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.Current edition approved Feb. 15, 2007. Published April 2007. Originallyapproved in 1985. Last previous edition approved in 2004 as D 4543 041*A Summary of Changes section appears at
16、the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.two systems may result in non-conformance with the standard.(Note, when mass measurements are added to determinedensities or unit weights, add the following.)1.7
17、.1 Only the SI units are used for mass determinations,calculations and reported results. However, the use of balancesor scales recording pounds of mass (lbm) shall not be regardedas nonconformance with this standard.1.8 This standard does not purport to address all of thesafety concerns, if any, ass
18、ociated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.9 This practice offers a set of instructions for performingone or more specific operations. This
19、document cannot replaceeducation or experience and should be used in conjunctionwith professional judgement. Not all aspects of this practicemay be applicable in all circumstances. This ASTM standard isnot intended to represent or replace the standard of care bywhich the adequacy of a given professi
20、onal service must bejudged, nor should this document be applied without consid-eration of a projects many unique aspects. The word “stan-dard” in the title of this document means only that thedocument has been approved through the ASTM consensusprocess.2. Referenced Documents2.1 ASTM Standards:2C 17
21、0 Test Method for Compressive Strength of DimensionStoneC 617 Practice for Capping Cylindrical Concrete Speci-mensD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD2113 Practice for Rock Core Drilling and Sampling ofRock for Site InvestigationD 2216 Test Methods for Laboratory Determinat
22、ion of Wa-ter (Moisture) Content of Soil and Rock by MassD 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 5079 Practices for Preserving and Transporting RockCore SamplesD 6026 Practice for Us
23、ing Significant Digits in Geotechni-cal DataD 7012 Test Method for Compressive Strength and ElasticModuli of Intact Rock Core Specimens under VaryingStates of Stress and TemperaturesD 7070 Test Method for Creep of Rock Core Under Con-stant Stress and Temperature3. Terminology3.1 For terminology used
24、 in this test method, refer toTerminology D 6534. Significance and Use4.1 The dimensional, shape, and surface tolerances of rockcore specimens are important for determining rock propertiesof intact specimens. Dimensional and surface tolerance checksare required in Test Methods D 7012 and D 7070. To
25、simplifytest procedures in laboratories, the parts of those proceduresthat are common to the test methods are given in this standard.NOTE 2The quality of the result produced by this standard isdependent upon the competence of the personnel performing it, and thesuitability of the equipment and facil
26、ities used. Agencies that meet thecriteria of Practice D 3740 are generally considered capable of competentand objective testing and sampling. Users of this standard are cautionedthat compliance with Practice D 3740 does not in itself assure reliableresults. Reliable results depend on many factors;
27、Practice D 3740 providesa means of evaluating some of those factors5. Apparatus5.1 Flat SurfaceThe tolerances of a flat test surface onwhich a rock specimen is rolled, a V-block placed, or the endof a rock core is placed shall not depart from a plane by morethan 0.0005 in. (13 m).5.2 V-blockThe V-bl
28、ock shall be machinist quality withall bearing faces surfaces ground flat, smooth to within 0.0005in. (13 m) and with a 90 included angle.5.3 Dial GageThe sensitivity of the dial gage shall be atleast 0.001 in. (25 m) for measurement of cylindrical surfaces.The measurement contact tip of the dial ga
29、ge shall be round inshape. A dial gage readable to 0.0001 in. (2.5 m) is requiredfor measurements on the end surfaces.5.4 Feeler GageThe feeler gage 3 in. (76 mm) “leaves”must include sizes beginning at 0.0015 in. (38 m).5.5 Surface GrinderA manual or automatic machinistssurface grinder equipped wit
30、h a magnetic flat surface and aV-block.5.6 Diamond SawA manual or automatic rock sawequipped with a segmented circular diamond saw blade, andappropriate cooling and cutting agents.6. Specimens6.1 Test specimens shall be right circular cylinders withinthe tolerances specified herein.6.2 The specimen
31、shall have a length-to-diameter ratio(L/D) of 2.0 to 2.5 and a diameter of not less than 1-78 in. (47mm).NOTE 3It is desirable that the diameter of rock test specimens be atleast ten times the diameter of the largest mineral grain. For weak rocktypes which behave more like soil (for example, weakly
32、cementedsandstone), the specimen diameter should be at least six times themaximum particle diameter. It is considered that the specified minimumspecimen diameter of approximately 1-78 in. (47 mm) will satisfy thiscriterion in the majority of cases. When cores of diameter smaller than thespecified mi
33、nimum must be tested because of the unavailability of largerdiameter core or prohibitive large drilling equipment siting costs, as isoften the case in the mining industry, suitable notation of this fact shall bemade in the report.6.3 The sides of the specimen shall be generally smooth andfree of abr
34、upt irregularities, with all the elements straight towithin 0.020 in. (0.50 mm) over the full length of the specimen,as determined by 7.1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
35、information, refer to the standards Document Summary page onthe ASTM website.D45430726.4 The ends of the specimen shall be cut parallel to eachother and at right angles to the longitudinal axis. The endsurfaces shall be surface ground or lapped flat to a tolerance notto exceed 0.001 in. (25 m), as d
36、etermined by 7.2.36.5 Sections 6.6 and 6.7 describe laboratory core drillingand cutting specimens from blocks of rock samples. PracticeD2113describes rock core drilling and sampling of rock forsite investigations. Water is normally a suitable fluid for rockcutting and grinding operations. However, s
37、ome rock materialsare sensitive to water and thus alternate suitable cooling andflushing fluids should be used. In sections 6.8 and 6.9 anair-cooled grinding unit with a dust collector is recommendedfor weak rocks and rocks that may react to fluids.6.6 Core Drilling Block SamplesAt least a 10 horsep
38、owerdrill, with a GFI for electrical powered drills is recommended.A thin walled core barrel with a water swivel and adaptors forhooking up the drill are recommended. Surface set diamondthin-wall bits are suited for soft rock. Impregnated diamondthin-wall bits are better suited for hard rock. Instal
39、l thethin-wall bit into the drill press chuck. Give the end of thethin-wall bit a tap with a rubber mallet to ensure it is snug.Lower the thin-wall bit to the drill table and mark the bit corebarrel for reference for sufficient drilling depth. Connect thecooling fluid hose to the swivel and tie it o
40、ut of the way. Placea sheet of12 in. (12.7 mm) plywood on the drill table, thenclamp the rock block securely to the table with clampingdevices such as chain vise locks. Block with wood wedges asnecessary to ensure the rock is secure and has a relatively flatdrilling surface. Turn on the cooling flui
41、d with sufficient flowto cool the bit and to flush the cuttings. With the bit raised offthe sample, turn on the drill using a slow speed. Lower the bitslowly onto the sample using a slow rotation speed until agroove is started. Use enough down force to prevent chatter butdo not allow the motor to sl
42、ow so much as to buzz. A loss ofdrill cooling fluid and the reference position mark indicates theend of the run. After breaking through, back the bit out of thehole and turn off the drill. If the core is not completely drilledthrough, remove the block and tap the bottom gently, thenremove the core.
43、Code and store the core.6.7 Specimen CuttingUse a segmented diamond saw forcutting core.Apply cooling fluid continuously to cool the bladeand flush cuttings from the cut. Automatic feed diamond sawsare recommended for cutting large rock specimens. Clamp thespecimen in the jig. Turn on the saw and ma
44、nually orautomatically cut the specimen perpendicular to its axis (see6.2 and 6.4) slowly avoiding blade chatter. Once the specimenis cut, back off the blade and turn off the saw. Remove, codeand store the specimen. When cutting weak or friable rock suchas potash, shale, etc., it is recommended the
45、core be firstencapsulated in polyolefin heat shrink tubing before cutting.6.8 Cylindrical Surface GrindingThe quality of the cir-cumferential surfaces of core specimens is usually acceptablefor most rock types, and no further surface finishing isrequired. If the drilled surface contains abrupt irreg
46、ularitieshowever, further finishing is recommended. This can beaccomplished by surface grinding in a lathe in much the sameway as dog bone specimens are prepared for direct tensile tests.The lathe chuck and center spindle are fitted with brass centershaving knurled end bearing surfaces. The specimen
47、 is heldbetween the brass centers by end pressure. A tool post grinderequipped with a diamond impregnated wheel is used to grindthe cylindrical surfaces. Diamond impregnated grindingwheels are best suited for grinding rock surfaces. Use coolingfluid to cool the surfaces and wash away cuttings.6.9 En
48、d Surface Grinding/LappingThere are several waysto prepare the end surfaces of a specimen. Using a machinisttable grinder, the core is clamped in a V-block and the V-blockis placed on the magnetic table. The specimen ends aretypically colored with a waterproof marker. Grind the end witha diamond imp
49、regnated grinding wheel. Silica carbide grindingwheels may also be used. Use cooling fluid to cool the surfacesand wash off the cuttings. Grind in increments of 0.002 in.(0.50 mm). Grinding is completed as evidenced by grindingstriations covering the whole end surface and the waterproofcoloring is completely removed. Reverse the core and grind theother end. Alternatively the core may be secured in the chuckof a lathe, and the end surfaces finished using a tool postdiamond grinding wheel. Lapping devices are available that lapboth ends of the core simultaneou
