1、Designation:D495907Standard Test Method forDetermination of Water(Moisture)Content of Soil By DirectHeating1This standard is issued under the fixed designation D4959;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last re
2、vision.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 procedures for determining thewater(moisture)content of soils by drying with direct heat,such as using a
3、hotplate,stove,blowtorch,etc.1.2 This test method can be used as a substitute for TestMethods D2216 when more rapid results are desired toexpedite other phases of testing and slightly less accurateresults are acceptable.1.3 When questions of accuracy between this test methodand Test Methods D2216 ar
4、ise,Test Methods D2216 shall bethe referee method.1.4 This test method is applicable for most soil types.Forsome soils,such as those containing significant amounts ofhalloysite,mica,montmorillonite,gypsum,or other hydratedmaterials,highly organic soils or soils that contain dissolvedsolids,(such as
5、salt in the case of marine deposits),this testmethod may not yield reliable water content values.1.5 The values stated in SI units are to be regarded asstandard.1.6 Refer to Practice D6026 for guidance concerning the useof significant figures.This is important if the water content willbe used to cal
6、culate other relationships such as moist mass todry mass or vice versa,wet unit weight to dry unit weight orvice versa,and total density to dry density or vice versa.Forexample,if four significant digits are required in any of theabove calculations,then the water content has to be recorded tothe nea
7、rest 0.1%.This occurs since 1 plus the water content(not in percent)will have four significant digits,While,if threesignificant digits are acceptable,then the water content can berecorded to the nearest 1%1.7 This standard does not purport to address all of thesafety concerns,if any,associated with
8、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 Me
9、thods 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 ConstructionD4753 Guide for Evaluating,Selecting,and Specifying Bal-ances an
10、d Standard Masses for Use in Soil,Rock,andConstruction Materials TestingD6026 Practice for Using Significant Digits in GeotechnicalData3.Terminology3.1 DefinitionsAll definitions are in accordance with Ter-minology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 direct heatinga process
11、 by which the soil is dried byconductive heating from the direct application of heat in excessof 110C to the specimen container,such as provided by a hotplate,gas stove or burner,heatlamps,or other heat sources.Direct application of heat by flame to the specimen is notappropriate.3.2.2 water(moistur
12、e)contentthe ratio,expressed as apercentage,of the mass of water in a given mass of soil to themass of the solid particles.4.Summary of Test Method4.1 A moist soil specimen is placed in a suitable containerand its mass is determined.It is then subjected to drying by theapplication of direct heat unt
13、il dry by appearance,removedfrom the heat source,and its new mass is determined.This1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.08 on Special andConstruction Control Tests.Current edition approved Feb.1,2007.Pu
14、blished March 2007.Originallyapproved in 1989.Last previous edition approved in 2000 as D4959 00 DOI:10.1520/D4959-07.2For 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
15、 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 procedure is repeated until the mass becomes nearly constantwithin specif
16、ied limits.4.2 The difference between the masses of the moist speci-men and the dried specimen is used as the mass of watercontained in the specimen.The water content(expressed as apercentage)is determined by dividing the mass of water by thedry mass of soil,multiplied by 100.For a given soil type andspecimen size,the time to achieve a constant dry mass can benoted and used to estimate drying time for subsequent tests ofthe same soil type using the same size specimen and dryingapparatus.5.Signif
