ASTM_D_5334_-_14.pdf

Designation:D533414Standard Test Method forDetermination of Thermal Conductivity of Soil and SoftRock by Thermal Needle Probe Procedure1This standard is issued under the fixed designation D5334;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 presents a procedure for determiningthe thermal conductivity()of soil and soft rock using atransient heat method.This test method is applicable for bothintact and reconstituted soil specimens and soft rock speci-mens.This test method is suitable only for homogeneousmaterials.1.2 This test method is applicable to dry or unsaturatedmaterials over temperatures ranging from 100C,depending on the suitability of the thermal needle probeconstruction to temperature extremes.However,care must betaken to prevent significant error from:(1)redistribution ofwater due to thermal gradients resulting from heating of theneedle probe;(2)redistribution of water due to hydraulicgradients(gravity drainage for high degrees of saturation orsurface evaporation);(3)phase change of water in specimenswith temperatures 100C.These errors can beminimized by adding less total heat to the specimen througheither minimizing power applied to the needle probe and/orminimizing the heating duration of the measurement.1.3 UnitsThe values stated in SI units are to be regardedas the standard.No other units of measurements are included inthis standard.1.4 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.4.1 The procedure 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 analyticalmethods for engineering design.1.5 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 ConstructionD4439 Terminology for GeosyntheticsD4753 Guide for Evaluating,Selecting,and Specifying Bal-ances and Standard Masses for Use in Soil,Rock,andConstruction Materials TestingD6026 Practice for Using Significant Digits in GeotechnicalData3.Terminology3.1 DefinitionsFor definitions of common technical terms,refer to Terminology standards D653 and D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 heat input,npower consumption of heater wire inwatts per unit length that is assumed to be the equivalent ofheat output per unit length of wire.3.2.2 thermal epoxy,nany heat conductive resin materialhaving a value of 4 W/(mK).3.2.3 thermal grease,nany heat conductive lubricatingmaterial having a value of 4 W/(mK).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 June 1,2014.Published July 2014.Originally approvedin 1992.Last previous edition approved in 2008 as D5334 08.DOI:10.1520/D5334-0814.2For 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.*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 4.Summary of Test Method4.1 Thermal conductivity is determined by a variation of theline source test method using a needle probe having a largelength to diameter ratio to simulate conditions for an infinitelylong,infinitely thin heating source.The probe consists of aheating element and a temperature measuring element and isinserted into the specimen.A known current and voltage areapplied to the probe and the temperature rise with time isrecorded over a period of time.The temperature decay withtime after th