1、Designation:C845/C845M12Standard Specification forExpansive Hydraulic Cement1This standard is issued under the fixed designation C845/C845M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parenth
2、eses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers hydraulic cements that expandduring the early hardening period after setting.1.2 The values stated in either SI units or inch-pou
3、nd unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.2.Referenced Documents2.1 ASTM Standards:2C
4、33 Specification for Concrete AggregatesC109/C109M Test Method for Compressive Strength ofHydraulic Cement Mortars(Using 2-in.or 50-mm CubeSpecimens)C114 Test Methods for Chemical Analysis of HydraulicCementC183 Practice for Sampling and the Amount of Testing ofHydraulic CementC185 Test Method for A
5、ir Content of Hydraulic CementMortarC188 Test Method for Density of Hydraulic CementC465 Specification for Processing Additions for Use in theManufacture of Hydraulic CementsC688 Specification for Functional Additions for Use inHydraulic CementsC806 Test Method for Restrained Expansion of ExpansiveC
6、ement MortarC807 Test Method for Time of Setting of Hydraulic CementMortar by Modified Vicat Needle3.Terminology3.1 Definitions:3.1.1 expansive cement(K)an expansive cement contain-ing anhydrous calcium aluminosulfate(4CaO3Al2O3SO3),calcium sulfate,and uncombined calcium oxide.3.1.2 expansive cement
7、(M)an expansive cement contain-ing calcium aluminate cement and calcium sulfate.3.1.3 expansive cement(S)an expansive cement contain-ing tricalcium aluminate(C3A)and calcium sulfate.3.1.4 expansive hydraulic cementa cement composed es-sentially of hydraulic calcium silicates,calcium aluminates andca
8、lcium sulfates,which,upon being mixed with water,forms apaste that increases significantly in volume during the earlyhardening period occurring after setting.This volume increaseis due principally to the reaction of the calcium aluminates andcalcium sulfates.3.1.5 shrinkage-compensating concreteconc
9、rete that is in-ternally restrained with resilient reinforcing and made withexpansive cement which induces both compressive stress in theconcrete and positive steel strain that approximately off-setstensile stresses and negative strains induced by drying shrink-age.4.Classification4.1 The cement cov
10、ered by this specification is suitable foruse in shrinkage-compensating concrete and shall be desig-nated as Type E-1.NOTE1Three kinds of expansive cement are identified in Section 3 bythe letters K,M,and S.The appropriate letter should be used as a suffixto the type designation when one of these ki
11、nds is desired.Expansivecement may also be prepared in other ways.5.Ordering Information5.1 When it is desired that an optional requirement apply orthat the cement be of a particular kind,a specific request to thiseffect should be made by the purchaser.6.Chemical Composition6.1 Expansive cement shal
12、l conform to the requirements asto chemical composition prescribed in Table 1.6.2 The purchaser has the option of specifying that thealkalies(Na2O+0.658K2O)shall not exceed 0.60%(SeeTable 2).1This specification is under the jurisdiction of ASTM Committee C01 onCement and is the direct responsibility
13、 of Subcommittee C01.13 on SpecialCements.Current edition approved Dec.15,2012.Published February 2013.Originallyapproved in 1976.Last previous edition approved in 2004 as C84504.DOI:10.1520/C0845-12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service a
14、t 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 NOTE2This limit should be specified when the cement is t
15、o be usedin concrete with aggregates that may be reactive.Reference should bemade to Specification C33 for suitable criteria of deleterious reactivity.7.Physical Properties7.1 Expansive cement shall conform to the physical require-ments prescribed in Table 3.8.Additions8.1 The cement covered by this
16、 specification shall containno additions except as follows:8.1.1 Water,or a functional addition,or both,that has beenshown to meet the requirements of Specification C688,may beadded in amounts such that the limits shown in Table 1 for losson ignition shall not be exceeded.8.1.2 At the option of the manufacturer,processing addi-tions may be used in the manufacture of the cement,providedsuch materials in the amounts used have been shown to be notharmful in accordance with Specification C465.9.Test
