ASTM_C_604_-_02_2012.pdf

Designation:C60402(Reapproved 2012)Standard Test Method forTrue Specific Gravity of Refractory Materials by Gas-Comparison Pycnometer1This standard is issued under the fixed designation C604;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.Scope1.1 This test method covers the determination of the truespecific gravity of solid materials,and is particularly useful formaterials that easily hydrate which are not suitable for test withTest Method C135.This test method may be used as analternate for Test Method C135,Test Method C128,and TestMethod C188 for determining true specific gravity.1.2 UnitsThe values stated in SI units are to be regardedas standard.No other units of measurement are included in thisstandard.1.2.1 ExceptionIn 7.3 the equivalent SI unit is expressedin parenthesis.1.3 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:2C128 Test Method for Density,Relative Density(SpecificGravity),and Absorption of Fine AggregateC135 Test Method for True Specific Gravity of RefractoryMaterials by Water ImmersionC188 Test Method for Density of Hydraulic Cement3.Summary of Test Method3.1 The sample is powdered to ensure permeation of gasinto all pores.For practical purposes this is assumed to be truewhen the sample passes a No.325(45-m)sieve.The volumeof a carefully weighed powdered sample which has first beenheated to drive off moisture and undesired combined water ismeasured by the gas-comparison pycnometer.Density is cal-culated from the sample weight in grams divided by its volumein cubic centimetres.This is also the specific gravity of thesample at room temperature compared to water at 4C.3.2 The principle of the gas-comparison pycnometer is asfollows:There are two chambers and two pistons as sketchedin Fig.1.For purposes of illustration,the chambers areassumed to be equal in volume,and there is no sample in eithercylinder.Under these conditions,with the coupling valveclosed,any change in the position of one piston must beduplicated by an identical stroke in the other in order tomaintain the same pressure on each side of the differentialpressure indicator.3.3 If a sample,Vx,is inserted into chamber B,the couplingvalve closed and both pistons advanced the same amount fromposition 1 to position 2,the pressures will not remain the same.However the pressures can be maintained equal if piston Binstead is moved only to position 3.Then the remainingdisplacement dx,from position 3 to position 2,is equal to thevolume of the sample,Vx.If piston A always is advancedexactly the same distance each time a measurement is made,the distance that piston B differs from position 2,when thepressures in both cylinders are equal,will always be propor-tional to the volume,Vx.The distance(dx)between positions 2and 3 can be calibrated and made to read directly in terms ofcubic centimetres,employing a digital counter.4.Significance and Use4.1 The true specific gravity of a material is the ratio of itstrue density,determined at a specific temperature,to the truedensity of water,determined at a specific temperature.Thus,the true specific gravity of a material is a primary propertywhich is related to chemical and mineralogical composition.4.2 This test method is particularly useful for hydratablematerials which are not suitable for test with Test MethodC135.4.3 For refractory raw materials and products the truespecific gravity is a useful value for:classification,detectingdifferences in chemical composition between supposedly likesamples,indicating mineralogical phases or phase changes,1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.03 on PhysicalProperties.Current edition approved Oct.1,2012.Published November 2012.Originallyapproved in 1967.Last previous edition approved in 2007 as C604 02(2007).DOI:10.1520/C0604-02R12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 calculating total porosity when the bulk density is known,andfor any other test method that requires this value for thecalculation of results.4.4 This test method is a primary standard method which issuitable for use in specifications,quality control,and researchand development.It can also se