ASTM_D_2936_-_20.pdf

Designation:D293620Standard Test Method forDirect Tensile Strength of Intact Rock Core Specimens1This standard is issued under the fixed designation D2936;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 the determination of the directtensile strength of the rock substance or discontinuities normalto the longitudinal axis of intact,isotropic cylindrical rockspecimens at room temperature.1.2 Non-isotropic or even transversely isotropic specimensare not covered by this standard.1.3 Cylindrical rock specimens can be drill core from thefield or rock blocks transported to the laboratory and drill corespecimen obtained there.1.4 Specimen shapes other than cylindrical specimens,suchas dog bone-shaped,are not covered by this standard.1.5 Test specimens may be tested under constant load ordeformation rate.1.6 The values stated in SI units are to be regarded asstandard.The values provided in parenthesis are for informa-tion only.1.7 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026 unless superseded by this standard.1.8 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.9 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD2113 Practice for Rock Core Drilling and Sampling ofRock for Site ExplorationD2216 Test Methods for Laboratory Determination of Water(Moisture)Content of Soil and Rock by MassD2845 Test Method for Laboratory Determination of PulseVelocities and Ultrasonic Elastic Constants of Rock(Withdrawn 2017)3D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4543 Practices for Preparing Rock Core as Cylindrical TestSpecimens and Verifying Conformance to Dimensionaland Shape TolerancesD5079 Practices for Preserving and Transporting Rock CoreSamples(Withdrawn 2017)3D6026 Practice for Using Significant Digits in GeotechnicalDataE4 Practices for Force Verification of Testing MachinesE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE2586 Practice for Calculating and Using Basic Statistics3.Terminology3.1 Definitions:3.1.1 For definitions of common technical terms used in thisstandard,refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:1This 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 Jan.1,2020.Published March 2020.Originallyapproved in 1971.Last previous edition approved in 2008 as D2936 08,whichwas withdrawn January 2017 and reinstated in January 2020.DOI:10.1520/D2936-20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.3.2.1 transverse isotropy,nimplies that,at any point in therock,there is an axis of symmetry of rotation and that the rockhas isotropic properties in a plane normal to this axis.4.Summary of Test Method4.1 A sample of rock cores or block samples,to be cored inthe laboratory,are obtained in the field and as needed to behandled in accordance with Practice D5079 or as directed bythe client.The test intervals in the rock core sample areselected,and the number of rock specimens selected,and thenthose core segments are cut to the specified length and anyrelevant pretesting documenta