ASTM筛析试验标准方法--D-422-63

Designation:D422—63(Reapproved2002)StandardTestMethodforParticle-SizeAnalysisofSoils颗粒分析试验标准方法1.Scope范围1.1Thistestmethodcoversthequantitativedeterminationofthedistributionofparticlesizesinsoils.Thedistributionofparticlesizeslargerthan75μm(retainedontheNo.200sieve)isdeterminedbysieving,whilethedistributionofparticlesizessmallerthan75μmisdeterminedbyasedimentationprocess,usingahydrometertosecurethenecessarydata(Note1andNote2).该试验方法用于定量分析土中粒径的分布。粒径大于75μm（保留在NO.200筛上）的土粒分布由筛分试验确定，而粒径小于75μm的土粒分布由沉降过程确定，沉降过程用一比重计获取必要的数据（注释1和注释2）。Note1—SeparationmaybemadeontheNo4(4.75-mm,),No(425-μm),orNo.200(75-μm)sieveinsteadoftheNo.10.Forwhateversieveused,thesizeshallbeindicatedinthereport.注释1—土试样分离可能在NO4（4.75mm），NO40（425μm）或NO200（75μm）筛上进行而不是NO10（2.00mm）筛。无论使用何种孔径的筛，都必需在报告中注明。Note2--Twotypesofdispersiondevicesareprovided:(l)ahigh-speedmechanicalstirrer,and(2)airdispersion.Extensiveinvestigationsindicatethatair-dispersiondevicesproduceamorepositivedispersionofplasticsoilsbelowthe20-pmsizeandappreciablylessdegradationonallsizeswhenusedwithsandysoils.Becauseofthedefiniteadvantagesfavoringairdispersion,itsuseisrecommended.Theresultsfromthetwotypesofdevicesdifferinmagnitude,dependinguponsoiltype,leadingtomarkeddifferencesinparticlesizedistribution,especiallyforsizesfinerthan20pan.注释2—提供两种散开装置：（1）一种高速的机械搅拌器，（2）空气散开装置。广泛的调查表明空气散开装置对20-μm以下的塑性土具有更有效的分散土粒的作用，更好的是对于砂性土能有效的减少土粒粒径的降级。由于空气散开装置明显的有利散开土粒的优点，建议使用该装置。两种装置效果的巨大不同，取决于土的类型，导致粒径分布的明显不同，特别是对于粒径小于20-μm的土粒。2.ReferencedDocuments参考文件2.1ASTMStandards:D421PracticeforDryPreparationofSoilSamplesforParticle-SizeAnalysisandDeterminationofSoilConstants.E11SpecificationforWire-ClothSievesforTestingPurposes.E100SpecificationforASTMHydrometers.3.Apparatus仪器设备3.1Balances-Abalancesensitiveto0.01gforweighingthematerialpassingaNo.10(2.00-mm)sieve,andabalancesensitiveto0.1%ofthemassofthesampletobeweighedforweighingthematerialretainedonaNo.10sieve.天平—最小称量为0.01g，用于称量通过NO10（2.00mm）筛的土粒，对于留在NO10（2.00mm）筛上的土粒，天平的称量精确度要达到样品质量的0.1%。3.2StirringApparatus-EitherapparatusAorBmaybeused.搅拌器—搅拌器A或搅拌器B均可。3.2.1ApparatusAshallconsistofamechanicallyoperatedstirringdeviceinwhichasuitablymountedelectricmotorturnsaverticalshaftataspeedofnotlessthan10000rpmwithoutload.Theshaftshallbeequippedwithareplaceablestirringpaddlemadeofmetal,plastic,orhardrubber,asshowninFig.1.Theshaftshallbeofsuchlengththatthestirringpaddlewilloperatenotlessthan3/4in.(19.0mm)normorethan211in.(38.1mm)abovethebottomofthedispersioncup.AspecialdispersioncupconformingtoeitherofthedesignsshowninFig.2shallbeprovidedtoholdthesamplewhileitisbeingdispersed.3.2.1搅拌器A：机器操作控制的搅拌装置，其电动垂直轴在无荷载下的旋转速度不小于10000rpm。轴应配备可更换的搅拌板，搅拌板可由金属、塑料或者硬塑料，如图1所示。轴的长度应满足运行时搅拌板离搅拌桶底部的距离不少于19mm，不大于38.1mm。一种特置的如图2中所示的任一搅拌桶也是整套仪器不可缺少的一部分，用于盛需搅拌分散的土试样。3.2.2ApparatusBshallconsistofanair-jetdispersioncups(Note3)conformingtothegeneraldetailsshowninFig.3(Note4andNote5).3.2.2搅拌器B：其主要组成部分为一带喷气的搅拌桶（注释3），如图3所示（注释4和注释5）。Note3-Theamountofairrequiredbyanair-jetdispersioncupisoftheorderof2ft3/min;somesmallaircompressorsarenotcapableofsupplyingsufficientairtooperateacup.注释3：一个喷射空气的搅拌桶需要的空气量为2ft3/min，一些小型的空气压缩机不能提供充足的空气量支持搅拌桶的运行。Note4-Anotherair-typedispersiondevice,knownasadispersiontube,developedbyChuandDavidsonatIowaStateCollege,hasbeenshowntogiveresultsequivalenttothosesecuredbytheairjetdispersioncups.Whenitisused,soakingofthesamplecanbedoneinthesedimentationcylinder,thuseliminatingtheneedfortransferringtheslurry.Whentheair-dispersiontubeisused,itshallbesoindicatedinthereport注释4：另一种空气型搅拌装置，带有一管子，由IowaState学院的Chu和Davidson发明，试验表明其效果与喷射空气搅拌桶的一致。使用时，浸泡试样可在沉降筒中进行，而不用将转移溶液。当试验中使用了空气搅拌管，在报告中也要指出。Note5-Watermaycondenseinairlineswhennotinuse.Thiswatermustberemoved,eitherbyusingawatertrapontheairline,orbyblowingthewateroutofthelicebeforeusinganyoftheairfordispersionpurposes注释5：当不使用时，水分可能空气传输线路中浓缩凝结。在使用空气振荡器分散土粒时，水必需排除，在空气传输线路中设置集水装置或者将其吹出。3.3Hydrometer-AnASTMhydrometer,graduatedtoreadineitherspecificgravityofthesuspensionorgramsperlitreofsuspension,andconformingtotherequirementsforhydrometers151Hor152HinSpecificationsE100.Dimensionsofbothhydrometersarethesame,thescalebeingtheonlyitemofdifference.3.3液体比重计—ASTM标准比重计，能用于测量悬浮液的比重或是每升的质量，遵从规范E100中的比重计151H或152H的技术要求。两种液体比重计的尺寸一致，唯一不同的是其刻度。3.4SedimentationCylinder-Aglasscylinderessentially18in.(457mm)inheightand212in.(63.5mm)indiameter,andmarkedforavolumeof1000-mL.Theinsidediametershallbesuchthatthe1000-mI,markis36±2cmfromthebottomontheinside.3.4沉降筒—一种高为457mm，直径为63.5mm的玻璃筒，标记容积为1000ml。其内径应满足从筒内底部至36±2cm高度的容积为1000-ml。3.5Thermometer-Athermometeraccurateto10F(0.50C)3.5温度计—温度计精度为1℉（0.5℃）。3.6Sieves-Aseriesofsieves,ofsquare-meshwoven-wirecloth;conformingtotherequirementsofSpecificationE11.Afullsetofsievesincludesthefollowing(Note6):3.6筛—一系列不同孔径的筛，其网格面积符合规范EⅡ的要求。整套标准筛包括下列孔径（注释6）：3-in.(75mm)No.10(2.00mm)2-in.(50mm)No.20(850μm)211-in.(37.5mm)No.40(425μm)1-in.(25.0mm)No.60(250μm)43-in.(19.0mm)No.140(106μm)83-in.(9.5mm)No.200(75μm)No.4(4.75mm)Note6-AsetofsievesasrequiredinSection17,uniformspacingofpointsfortheusedifdesired-Thissetconsistsfollowingsieves:注释6——在17节里，整套标准筛在筛分曲