1、Designation:D221619Standard Test Methods forLaboratory Determination of Water(Moisture)Content ofSoil and Rock by Mass1This standard is issued under the fixed designation D2216;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、 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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 These test methods cover the labo
3、ratory determinationof the water(moisture)content by mass of soil,rock,andsimilar materials where the reduction in mass by drying is dueto loss of water except as noted in 1.4,1.5,and 1.8.Forsimplicity,the word“material”shall refer to soil,rock oraggregate whichever is most applicable.1.2 Some disci
4、plines,such as soil science,need to deter-mine water content on the basis of volume.Such determina-tions are beyond the scope of this test method.1.3 The water content of a material is the ratio of the massof water contained in the pore spaces of soil or rock material,to the solid mass of particles,
5、expressed as a percentage.1.4 The term“solid material”as used in geotechnicalengineering is typically assumed to mean naturally occurringmineral particles of soil and rock that are not readily soluble inwater.Therefore,the water content of materials containingextraneous matter(such as cement etc.)ma
6、y require specialtreatment or a qualified definition of water content.In addition,some organic materials may be decomposed by oven drying atthe standard drying temperature for this method(110 6 5C).Materials containing gypsum(calcium sulfate dihydrate)orother compounds having significant amounts of
7、hydratedwater,may present a special problem as this material slowlydehydrates at the standard drying temperature(110 6 5C)andat very low relative humidity,forming a compound(such ascalcium sulfate hemihydrate)that is not normally present innatural materials except in some desert soils.In order to re
8、ducethe degree of dehydration of gypsum in those materialscontaining gypsum or to reduce decomposition in highly/fibrous organic soils,it may be desirable to dry the materials at60C or in a desiccator at room temperature.When a dryingtemperature is used which is different from the standard dryingtem
9、perature as defined by this test method,the resulting watercontent may be different from the standard water contentdetermined at the standard drying temperature of 110 6 5C.NOTE1Test Method D2974 provides an alternate procedure fordetermining water content of peat materials.1.5 Materials containing
10、water with substantial amounts ofsoluble solids(such as salt in the case of marine sediments)when tested by this method will give a mass of solids thatincludes the previously soluble dissolved solids.These mate-rials require special treatment to remove or account for thepresence of precipitated soli
11、ds in the dry mass of the specimen,or a qualified definition of water content must be used.Forexample,see Test Method D4542 regarding information onmarine sediments.1.6 This test standard requires several hours for properdrying of the water content specimen.Test Methods D4643,D4944 and D4959 provide
12、 less time-consuming processes fordetermining water content.See Gilbert2for details on thebackground of Test Method D4643.1.7 Two test methods are provided in this standard.Themethods differ in the significant digits reported and the size ofthe specimen(mass)required.The method to be used may bespec
13、ified by the requesting authority;otherwise MethodAshallbe performed.1.7.1 Method AThe water content by mass is recorded tothe nearest 1%.For cases of dispute,Method A is the refereemethod.1.7.2 Method BThe water content by mass is recorded tothe nearest 0.1%.1.8 This standard requires the drying of
14、 material in an oven.If the material being dried is contaminated with certainchemicals that may react violently or emit hazardous gaseswhen heated,health and safety hazards may exist.Therefore,this standard should not be used in determining the watercontent of contaminated soils unless adequate heal
15、th and safetyprecautions are exercised.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.03 on Texture,Plasticityand Density Characteristics of Soils.Current edition approved March 1,2019.Published March 2019.Origina
16、llyapproved in 1963.Last previous edition approved in 2010 as D221610.DOI:10.1520/D2216-19.2Gilbert,P.A.,“Computer Controlled Microwave Oven System for Rapid WaterContent Determination,”Tech.Report GL-8821,Department of the Army,Water-ways Experiment Station,Corps of Engineers,Vicksburg,MS,November 1988.*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 sta
