1、Designation:C157/C157M08(Reapproved 2014)1Standard Test Method forLength Change of Hardened Hydraulic-Cement Mortar andConcrete1This standard is issued under the fixed designation C157/C157M;the number immediately following the designation indicates the yearof original adoption or,in the case of rev
2、ision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript 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.1NOTEEditorial corrections wer
3、e made in November 2014.1.Scope*1.1 This test method covers the determination of the lengthchanges that are produced by causes other than externallyapplied forces and temperature changes in hardened hydraulic-cement mortar and concrete specimens made in the laboratoryand exposed to controlled condit
4、ions of temperature andmoisture.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.An exception is withregard to sieve sizes and nominal size of aggregate,in whichthe SI values are the standard as stated in Specification E11.Within the text,the SI u
5、nits are shown in brackets.The valuesstated in each system may not be exact equivalents;therefore,each system shall be used independently of the other.Combin-ing values from the two systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of thesafety
6、 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:2C125 Terminology Relating to Concrete
7、and Concrete Ag-gregatesC143/C143M Test Method for Slump of Hydraulic-CementConcreteC172 Practice for Sampling Freshly Mixed ConcreteC192/C192M Practice for Making and Curing Concrete TestSpecimens in the LaboratoryC305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic
8、ConsistencyC490 Practice for Use ofApparatus for the Determination ofLength Change of Hardened Cement Paste,Mortar,andConcreteC511 Specification for Mixing Rooms,Moist Cabinets,Moist Rooms,and Water Storage Tanks Used in theTesting of Hydraulic Cements and ConcretesC596 Test Method for Drying Shrink
9、age of Mortar Contain-ing Hydraulic CementC1437 Test Method for Flow of Hydraulic Cement MortarE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE337 Test Method for Measuring Humidity with a Psy-chrometer(the Measurement of Wet-and Dry-Bulb Tem-peratures)3.Terminology3.1 DefinitionsTh
10、e terms used in this test method aredefined in Terminology C125.3.2 Definitions of Terms Specific to This Standard:3.2.1 length change,nan increase or decrease in thelength of a test specimen that has been caused to change by anyfactor other than externally applied forces and temperaturechanges.4.Si
11、gnificance and Use4.1 Measurement of length change permits assessment ofthe potential for volumetric expansion or contraction of mortaror concrete due to various causes other than applied force ortemperature change.This test method is particularly useful forcomparative evaluation of this potential i
12、n different hydraulic-cement mortar or concrete mixtures.4.2 This test method provides useful information for experi-mental purposes or for products that require testing undernonstandard mixing,placing,handling,or curing conditions,1This test method is under the jurisdiction of ASTM Committee C09 on
13、Concrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.68 on Volume Change.Current edition approved Oct.1,2014.Published November 2014.Originallyapproved in 1940.Last previous edition approved in 2008 as C157/C157M 081.DOI:10.1520/C0157_C0157M-08R14E01.2For referenced A
14、STM 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM Int
15、ernational,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 FIG.1 AtmometerC157/C157M 08(2014)12 such as high product workability or different demolding times.Standard conditions are described in 5.4.1.4.3 If conditions for mixing,curing,sampling,and storageother than
16、 specified in this test method are required,they shallbe reported but are not to be considered as standard conditionsof this test method.Nonstandard conditions and the reasons fordeparture from standard conditions shall be reported clearlyand prominently with comparator values.5.Apparatus5.1 Molds and Length ComparatorThe molds for castingtest specimens and the length comparator for measuring lengthchange shall conform to the requirements of Practice C490.5.2 TamperThe tamper shall be made of a