1、Designation:C512/C512M15Standard Test Method forCreep of Concrete in Compression1This standard is issued under the fixed designation C512/C512M;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 par
2、entheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the creepof molded concrete cylinders subjected to sustained longitudi-nal compressive load.This test meth
3、od is limited to concrete inwhich the maximum aggregate size does not exceed 50 mm 2in.1.2 The values 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 o
4、f the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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 prac
5、tices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C39/C39M Test Method for Compressive Strength of Cylin-drical Concrete SpecimensC125 Terminology Relating to Concrete and Concrete Ag-gregatesC192/C192M Practice for Making and Cur
6、ing Concrete TestSpecimens in the LaboratoryC470/C470M Specification for Molds for Forming ConcreteTest Cylinders VerticallyC617 Practice for Capping Cylindrical Concrete SpecimensC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials3.Terminology3.1 For
7、 definitions of terms used in this test method refer toTerminology C125.4.Significance and Use4.1 This test method measures the load-induced time-dependent compressive strain at selected ages for concreteunder an arbitrary set of controlled environmental conditions.4.2 This test method can be used t
8、o compare creep poten-tials of different concretes.A procedure is available,using thedeveloped equation(or graphical plot),for calculating stressfrom strain data within massive non-reinforced concrete struc-tures.For most specific design applications,the test conditionsset forth herein must be modif
9、ied to more closely simulate theanticipated curing,thermal,exposure,and loading age condi-tions for the prototype structure.Current theories and effects ofmaterial and environmental parameters are presented in ACISP-135,Symposium on Creep and Shrinkage of Concrete:Effect of Materials and Environment
10、.34.3 In the absence of a satisfactory hypothesis governingcreep phenomena,a number of assumptions have been devel-oped that have been generally substantiated by test andexperience.4.3.1 Creep is proportional to stress from 0 to 40%ofconcrete compressive strength.4.3.2 Creep has been conclusively sh
11、own to be directlyproportional to paste content throughout the range of pastecontents normally used in concrete.Thus,the creep character-istics of concrete mixtures containing aggregate of maximumsize greater than 50 mm 2 in.may be determined from thecreep characteristics of the minus 50-mm minus 2-
12、in.fractionobtained by wet-sieving.Multiply the value of the character-istic by the ratio of the cement paste content(proportion byvolume)in the full concrete mixture to the paste content of thesieved sample.4.4 The use of the logarithmic expression(Section 9)doesnot imply that the creep strain-time
13、 relationship is necessarilyan exact logarithmic function;however,for the period of one1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.61 on Testing for Strength.Current edition approved Oct.1,20
14、15.Published December 2015.Originallyapproved in 1963.Last previous edition approved in 2010 as C512/C512M10.DOI:10.1520/C0512_C0512M-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume infor
15、mation,refer to the standards Document Summary page onthe ASTM website.3SP-135 is currently out of print,however,the individual papers contained in thepublication are available from American Concrete Institute(ACI),P.O.Box 9094,Farmington Hills,MI 48333-9094,http:/www.concrete.org.Copyright ASTM Int
16、ernational,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 year,the expression approximates normal creep behavior withsufficient accuracy to make possible the calculation of param-eters that are useful for the purpose of comparing concretes.4.5 There are no data that would support the extrapolationof the results of this test to tension or torsion.5.Apparatus5.1 MoldsMolds shall be cylindrical conforming to theprovisions of Practice C192/C192M,or to the provisions
