ASTM_D_3967_-_16.pdf

Designation:D396716Standard Test Method forSplitting Tensile Strength of Intact Rock Core Specimens1This standard is issued under the fixed designation D3967;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 This test method covers testing apparatus,specimenpreparation,and testing procedures for determining the split-ting tensile strength of rock by diametral line compression ofdisk shape specimens.NOTE1The tensile strength of rock determined by tests other than thestraight pull test is designated as the“indirect”tensile strength and,specifically,the value obtained in Section 9 of this test is termed the“splitting”tensile strength.1.2 UnitsThe values stated in SI units are to be regardedas standard.The values given in parentheses are mathematicalconversions to inch-pound units,which are provided forinformation only and are not considered standard.Reporting oftest results in units other than SI shall not be regarded asnonconformance with this test method.1.3 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.3.1 The procedures used to specify how data are collected/recorded or calculated,in this standard are regarded as theindustry standard.In addition,they are representative of thesignificant digits that generally should be retained.The proce-dures 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 scopeof this standard to consider significant digits used in analysismethods for engineering design1.4 This standard does not purport to address all of thesafety concerns,if any,associated 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.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD2216 Test Methods for Laboratory Determination of Water(Moisture)Content of Soil and Rock by MassD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalDataE4 Practices for Force Verification of Testing MachinesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2586 Practice for Calculating and Using Basic Statistics3.Terminology3.1 Definitions:3.1.1 For common definitions of terms in this standard,referto Terminology D653.4.Summary of Test Method4.1 Samples are selected from rock cores or cored fromplaten samples for testing as described.A section of rock coresample is cut perpendicular to the core axis to produce diskshape specimens until the required number of specimens areobtained.Each specimen is then marked to indicate the desiredorientation of the applied loading on the specimen by drawinga diametral line on each end surface on the specimen.Eachspecimen is positioned inside the testing machine in such waythat diametrical line is coincidental with the loading axis of thetesting machine either curved or flat platens.Each specimen isthen tested by applying a continuously increasing compressiveload until it fails within 1 to 10 minutes of the start of loading.5.Significance and Use5.1 By definition the tensile strength is obtained by thedirect tensile test.However,the direct tensile test is difficult1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.Current edition approved Nov.1,2016.Published November 2016.Originallyapproved in 1981.Last previous edition approved in 2008 as D3967 08.DOI:10.1520/D3967-16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandardsvolume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 and expensive for routine application.The splitting tensile testappears to offer a desirable alternative,because it is muchsimpler and inexpensive.Furthermore,engineers involved inrock mechanics design usually deal with complicated stressfields,including various combinations of compressive andtensile stress fields.Under such conditions,the tensile strengthshould be obtained wi