ASTM_D_4543_-_19.pdf

Designation:D454319Standard Practices forPreparing Rock Core as Cylindrical Test Specimens andVerifying Conformance to Dimensional and ShapeTolerances1This standard is issued under the fixed designation D4543;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 These practices specify procedures for preparing rocktest specimen of rock core from drill core obtained in the fieldor from block samples for strength and deformation testing andfor determining the conformance of the test specimen dimen-sions with tolerances established by this practice.Cubical,rectangular,or other shapes are not covered by this practice.However,some of the information contained within thispractice and in standard Test Method C170 may still be of useto preparing other 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 natural 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 or weak(orboth)structural features.For rock types which are difficult toprepare,all reasonable efforts should be made to prepare aspecimen in accordance with this practice and for the intendedtest procedure.However,when it has been determined by trialand error that this is not possible,prepare 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.NOTE1Best effort in surface preparation refers to the use of awell-maintained,suitable surface grinder,lathe or lapping machine andany required ancillary equipment are utilized by an experienced operatorand in which a reasonable number of attempts has been made to meet thetolerances required in this procedure.1.3 This practices covers some,but not all of the curatorialissues that should be implemented.For curatorial issues thatshould be followed before and during specimen preparationrefer to Practices D5079 and to the specific test standards in 2.1for which the specimens are being prepared.1.4 This practice also prescribes tolerance checks on thelength-to-diameter ratio,straightness of the elements on thecylindrical surface,the flatness of the end bearing surfaces,andthe perpendicularity of the end surfaces with the axis of thecore.NOTE2This practice does not purport to cover all the issues that willor could be encountered that may control the quality of the specimenpreparation required.Each laboratory may have their own issues,espe-cially for different compression load frames or rock types.For example,stiff testing frames versus traditional load frames and loading platens withor without spherical seating.Specimens for a stiff testing load frame withno spherical seat may need to have more stringent requirements dependingon the type of rock being tested.This procedure has tried to show themethods and QA that may be involved while keeping in mind thosematerials that are difficult to work with and for which the specimens willstill be suitable to be tested.The available literature and input on thissubject from D18.12 members were considered as much as possible forthis standard.21.5 The requirement for specifying the moisture conditionand volume of the test specimen is also stated.However,therequirements in the specific test standards in 2.1 should befollowed too.1.6 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026,unless superseded by this standard.1.6.1 The practices/procedures used to specify how data arecollected/recorded and calculated 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 users objectives;and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations.It is beyond the scope1These practices are under the jurisdiction ofASTM Committee D18 on Soil andRock and are the direct responsibility of Subcommittee D18.12 on Rock Mechanics.Current edition approved June 1,2019.Published July 2019.Originally approvedin 1985.Last previous edition approved in 2008 as D4543 081.DOI:10.1520/D4543-19.2Needless Stringency in Sample Preparation Standards