ASTM_C_472_-_99_2014.pdf

Designation:C47299(Reapproved 2014)Standard Test Methods forPhysical Testing of Gypsum,Gypsum Plasters and GypsumConcrete1This standard is issued under the fixed designation C472;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods cover the physical testing ofgypsum,gypsum plasters,and gypsum concrete.1.2 The test methods appear in the following sections:SectionsPrecautions for Physical Tests4Reagents and Materials5Free Water6Fineness7Normal Consistency of Gypsum Plaster8Normal Consistency of Gypsum Concrete9Setting Time10Setting Time(Temperature Rise Method)11Compressive Strength12Density131.3 The values regarded as the standard are either ininch-pound units or SI(metric).The values stated first shall beregarded as the standard.Values following in parentheses areapproximate and are provided for information purposes only.1.4 The text of this standard references notes and footnoteswhich provide explanatory material.These notes and footnotes(excluding those in tables and figures)are not requirements ofthe standard.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.For a specificprecautionary statement,see X1.2.1.2.Referenced Documents2.1 ASTM Standards:2C11 Terminology Relating to Gypsum and Related BuildingMaterials and SystemsC778 Specification for SandE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Terminology3.1 Definitions:3.1.1 For useful definitions refer to Terminology C11.4.Precautions for Physical Tests4.1 Gypsum products are greatly affected by small amountsof impurities introduced by careless laboratory manipulation.In order to obtain accurate results,it is absolutely essential toobserve the following precautions:4.1.1 Keep all apparatus thoroughly clean.Remove alltraces of set plaster.NOTE1For mixing pastes and mortars,a 500-ml rubber dental bowlis a convenience.NOTE2Use care when drying gypsum,gypsum plasters,or gypsumconcrete.Exceeding the specified drying temperatures may calcine thespecimens,which will cause inaccurate test results.5.Reagents and Materials5.1 Distilled or Deionized Waterfree of chlorides andsulfates at a temperature of 21 6 1C(70 6 2F).5.2 Standard Sand Specification C778,2030 sand.1These test methods are under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and are the direct responsi-bility of Subcommittee C11.01 on Specifications and Test Methods for GypsumProducts.Current edition approved April 1,2014.Published April 2014.Originallyapproved in 1961.Last previous edition approved in 2009 as C47299(2009).DOI:10.1520/C0472-99R14.2For 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 6.Free Water6.1 Significance and UseThis test method determines thefree water contained in gypsum,gypsum plasters,and gypsumconcrete samples,and prepares the sample for subsequenttesting.6.2 Apparatus:6.2.1Balance,capable of weighing not less than 500 g ata precision of 0.1 g.6.2.2Drying Oven,set at 45 6 3C.6.2.3Desiccator,containing calcium chloride or equiva-lent desiccant.6.3 Procedure:6.3.1 Weigh a sample of not less than 500 g of the materialas received to the nearest 0.1 g and spread it to a thin layer ina suitable-vessel.Place in an oven(6.2.2)and dry for 2 h;thencool in a desiccator(6.2.3)and weigh again.6.3.2 Retain the dried sample in an airtight container untilused for the fineness test(Section 7).6.4 ReportReport the loss in weight as a percentage of theoriginal weight of the sample as received to a precision of0.1%.6.5 Precision and BiasThe precision and bias of the freewater test method have not been determined.7.Fineness7.1 Significance and UseThis test method covers a proce-dure for determining the fineness of gypsum and gypsumplasters and is used to determine compliance with gypsum andgypsum plaster specifications.The degree of correlation be-tween the results of this test method and service performancehas not been determined.7.2 Apparatus:7.2.1 Sieves,as required by a particular gypsum or gypsumplaster specification,in accordance with Specification E11.7.2.2 Balance,capable of weighing not less than 1000 g ata precision of 0.1 g.7.2.3 Mechanical Sieving Machin