ASTM_A_1061_-_A_1061M_-_16.pdf

Designation:A1061/A1061M16Standard Test Methods forTesting Multi-Wire Steel Prestressing Strand1This standard is issued under the fixed designation A1061/A1061M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods describe procedures for testing themechanical properties of multi-wire steel prestressing strand.1.2 These test methods are intended for use in evaluatingspecific strand properties prescribed in specifications for multi-wire steel prestressing strand,but they do not quantify accep-tance criteria specified in the applicable specification for thestrand being tested.1.3 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard.Within the text,theSI units are shown in brackets.The values stated in eachsystem may not be exact equivalents;therefore,each systemshall be used independently of the other.Combining valuesfrom the two systems may result in non-conformance with thestandard.1.4 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.2.Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsE4 Practices for Force Verification of Testing MachinesE83 Practice for Verification and Classification of Exten-someter SystemsE328 Test Methods for Stress Relaxation for Materials andStructures3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 breaking strength,nmaximum force at or afterwhich one or more wires fracture.3.1.2 free span,nthe distance between the gripping jawsoccupied by the length of strand to be tested in which the strandis not contacted or detrimentally influenced by the grippingsystem.3.1.3 lay length,nthe axial distance required to make onecomplete revolution of any wire of a strand.3.1.4 strand,na group of two,three or seven steel wireswound together in a helical form with uniform lay length of notless than 12 and not more than 16 times the nominal diameterof the strand.3.1.5 yield strength,nmeasured force at 1.0%extensionunder load(EUL).4.Significance and Use4.1 The breaking strength and elongation of the strand aredetermined by one or more tensile tests in which fracture of thespecimen ideally occurs in the free span.4.2 Mechanical properties of the strand will be negativelyaffected if proper care is not taken to prevent damage such assevere bending,abrasion,or nicking of the strand duringsampling.4.3 Premature failure of the test specimens may result ifthere is appreciable notching,cutting,or bending of thespecimen by the gripping devices of the testing machine.4.4 Errors in testing will result if the wires constituting thestrand are not loaded uniformly.4.5 The mechanical properties of the strand will be materi-ally affected by excessive heating during test specimen collec-tion or preparation.5.Apparatus5.1 Tensile testing machine calibrated in accordance withPractices E4.5.2 Class B-1 extensometer as described in Practice E83.5.3 Class D extensometer as described in Practice E83;alternately,a linear dial gauge or ruler with precision of 6116in.1.5 mm.1These test methods are under the jurisdiction of ASTM Committee A01 onSteel,Stainless Steel and Related Alloys and is the direct responsibility ofSubcommittee A01.05 on Steel Reinforcement.Current edition approved March 1,2016.Published April 2016.Originallyapproved in 2009.Last previous edition approved in 2009 as A1061/A1061M 09.DOI:10.1520/A1061_A1061M-16.2For 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.Sampling6.1 Unless otherwise specified in the applicable specifica-tion for the strand being tested,test specimens shall be takenfrom the finished strand prior to packaging.The number of testspecimens shall be taken as specified in the applicable speci-fication for the strand being tested.7.Gripping Devices7.1 Due to inherent physical characteristics of individualtensile testing machines,it is not practical to recommend auniversal gripping method that is suitable for all tensile testingmachines.Therefore,it is necessary to determine which of themethods of gripping described in 7.1.1 7.1.3 is most suitablefor the tensile testing machine available.The gripping devicesshall be designed such that during testing the load is distributedalong the entire