1、Designation:C878/C878M14aStandard Test Method forRestrained Expansion of Shrinkage-CompensatingConcrete1This standard is issued under the fixed designation C878/C878M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last r
2、evision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of the expan-sion of concrete made with shrinkage-compensating cement.1.2 The values
3、stated in either SI units or inch-pound 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.1.3 Th
4、is 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.(WarningFreshhydraulic c
5、ementitious mixtures are caustic and may causechemical burns to skin and tissue upon prolonged exposure.2)2.Referenced Documents2.1 ASTM Standards:3C125 Terminology Relating to Concrete and Concrete Ag-gregatesC192/C192M Practice for Making and Curing Concrete TestSpecimens in the LaboratoryC219 Ter
6、minology Relating to Hydraulic CementC490 Practice for Use ofApparatus for the Determination ofLength Change of Hardened Cement Paste,Mortar,andConcreteC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC806 Test Method for Restrained Expansion of Exp
7、ansiveCement MortarC845 Specification for Expansive Hydraulic Cement2.2 ACI Standards and Committee Reports:4CT ACI Concrete Terminology223R Guide for the Use of Shrinkage-Compensating Con-crete3.Terminology3.1 Terms used in this test method are defined in Terminolo-gies C219 and C125.NOTE1Additiona
8、l terms not found in Terminologies C219 or C125may be found in ACI CT.4.Significance and Use4.1 Since the potential for expansion,under conditions ofcontrolled restraint,of concrete made with shrinkage-compensating cement cannot always be satisfactorily predictedfrom tests of mortars made in accorda
9、nce with Test MethodC806,a need has been recognized for a test method in whichconcrete specimens are tested.4.2 This test method can also be adapted readily to studiesof expansion involving degrees of restraint,comparisons ofcements,effects of cement contents,mixture proportions,schedules,or environ
10、mental treatments that differ from thestandard procedures prescribed by this test method.5.Apparatus5.1 Molds,for casting test specimens,when used in con-junction with the restraining cage described in 4.2,shallprovide for forming prisms 76 mm 3 in.square with a gagelength of 250 mm 10 in.The molds
11、shall otherwise conformto the requirements for molds in Practice C490,except that thestud holder,gage studs,and spacer screws described in thatpractice will not be used.5.2 Restraining Cage,consisting of a threaded low-carbonsteel rod(plain or zinc-coated)with steel end plates held inplace by hex nu
12、ts as shown in Fig.1.The hex nuts outside thecage shall be of stainless steel.Stainless steel cap nuts shall beput on each end of the rod.When tested in tension,within the1This method is under the jurisdiction of ASTM Committee C09 on Concreteand Concrete Aggregates and is the direct responsibility
13、of Subcommittee C09.68on Volume Change.Current edition approved July 1,2014.Published July 2014.Originally approvedin 1978.Last previous edition approved in 2014 as C878 14.DOI:10.1520/C0878_C0878M-14A.2Section on Safety Precautions,Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standa
14、rds,Vol.04.02.3For 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.4Available from American Concrete Institute(ACI),P.O
15、.Box 9094,FarmingtonHills,MI 48333-9094,http:/www.concrete.org.*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 States1 elastic range,the rod shall have a strain of 2800 kN 0.0012 60
16、.0001/630 lbf of load(Note 2).NOTE2It is intended that all rods used meet the indicated requirementfor strain.When a large number of rods are obtained as a single lot,exercise judgment as to whether or not all must be tested.The designation“10-24”is used in ordinary rods having the desired properties.5.3 Length Comparator,conforming to and to be used inaccordance with the requirements of Practice C490.Use areference bar complying with the description given in PracticeC490.If the terminals of the
