1、Designation:A416/A416M-17aNTERNATIONALStandard Specification forLow-Relaxation,Seven-Wire Steel Strand for PrestressedConcrete1This standard is issued under the fixed designation A416/A416M:the number immediately following the designation indicates the yearof original adoption or,in the case of revi
2、sion,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.1.Scope2.Referenced Documents1.
3、1 This specification covers two grades of low-relaxation,2.1 ASTM Standards:2seven-wire steel strand for use in prestressed concrete con-A981/A981M Test Method for Evaluating Bond Strength forstruction.Grade 250 1725and Grade 270 1860have0.600-in.15.24-mmDiameter Steel Prestressing Strand,minimum te
4、nsile strengths of 250 ksi 1725 MPaand 270 ksiGrade 270 1860.Uncoated,Used in Prestressed Ground1860 MPa,respectively,based on the nominal area of theAnchorsstrand.A1061/A1061M Test Methods for Testing Multi-Wire SteelPrestressing Strand1.2 A supplementary requirement(S1)is provided for use2.2 U.S.M
5、ilitary Standard:where bond strength testing of 0.600-in.15.24-mmdiameterMIL-STD-129 Marking for Shipment and StorageGrade 270 1860strand for applications in prestressed ground2.3 U.S.Federal Standard:3anchors is required by the purchaser.The supplementaryFed.Std.No.123 Marking for Shipments(Civil A
6、gencies)requirement applies only when specified in the purchase order.1.3 The text of this specification contains notes or footnotes,3.Terminologyor both,that provide explanatory material.Such notes and3.1 Definition of Term Specific to This Specification:footnotes do not contain any mandatory infor
7、mation.3.1.1 strand,n-a group of wires having a center wireenclosed tightly by six helically placed outer wires with1.4 This specification is applicable for orders in eitheruniform pitch of not less than 12 and not more than 16 timesinch-pound units(as Specification A416)or in SI units(asthe nominal
8、 diameter of the strand.Specification A416M)3.1.1.1 Discussion-The direction of lay is either right-1.5 The values stated in either inch-pound units or SI unitshanded or left-handed.are to be regarded separately as standard.Within the text,theSI units are shown in brackets.The values stated in each4
9、.Ordering Informationsystem may not be exact equivalents;therefore,each system4.1 Orders for low-relaxation seven-wire steel strand undershall be used independently of the other.Combining valuesthis specification shall contain the following information:from the two systems may result in non-conforma
10、nce with the4.1.1 Quantity(feet metres),specification.4.1.2 Nominal diameter of strand(inches millimetres),4.1.3 Grade of strand,and1.6 This international standard was developed in accor-4.1.4 ASTM designation A416 A416Mand year of issue.dance with internationally recognized principles on standard-i
11、zation established in the Decision on Principles for the4.2 The purchaser shall have the option to specify additionalDevelopment of International Standards,Guides and Recom-requirements,including but not limited to,the following:mendations issued by the World Trade Organization Technical4.2.1 Relaxa
12、tion evidence for similarly dimensioned strandBarriers to Trade(TBT)Committee.of the same grade(6.5.1),4.2.2 Specially dimensioned strand(7.4),This specification is under the jurisdiction of ASTM Committee A01 on Steel,2 For referenced ASTM standards,visit the ASTM website,www.astm.org,orStainless S
13、teel and Related Alloys and is the direct responsibility of Subcommitteecontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMA01.05 on Steel Reinforcement.Standards volume information,refer to the standards Document Summary page onCurrent edition approved Dec.1,2017.Published Dece
14、mber 2017.Originallythe ASTM website.approved in 1957.Last previous edition approved in 2017 as A416/A416M-17.3 Available from DLA Document Services,Building 4/D,700 Robbins Ave.,DOL:10.1520WA0416_A0416M-17A.Philadelphia,PA 19111-5094.http:/quicksearch.dla.mil.*A Summary of Changes section appears a
15、t the end of this standardCopyright ASTM Intemational,100 Barr Harbor Drive,PO Box C700.West Conshohocken.PA 19428-2959.United States1A416/A416M-17aTABLE 1 Breaking Strength Requirements5.Materials and ManufactureNominal DiameterMinimum BreakingSteel Area ofWeight Massof5.1 Base Metal-The base metal
16、 shall be carbon steel ofof Strand,in.mmStrength ofStrand,in.2 mm2Strand Ib/1000 ftStrand,Ibf kNkg/1000msuch quality that when drawn to wire,fabricated into strand.Grade2501725and then thermally treated,shall have the properties and0.2506.4900040.010.036231122182characteristics prescribed in this sp
17、ecification.0.3137.911450064.50.058371972940.3759.52000089.00.0805212724055.2 Wire-The wire from which the strand is to be fabricated0.43811.127000120j0.10869.7刀367【548shall be round and have a dry-drawn finish.0.50012.7刀36000160j0.14492.9149073010.60015.2540002400.2161397371090NorE 1-This product i
18、s a composite of seven wires and is producedGrade 270 1860only to meet the prescribed mechanical properties.The chemical compo-0.3759.531230001020.085552904300.43811.1310001380.11574.2390580sition of all wires or any individual wire is not pertinent to this application,0.500【12.7413001840.15398.7752
19、0T7801and heat identity is not necessarily maintained.It is possible that wire0.520【13.214500020010.167108570840from more than one heat may be used in the manufacture of a reel or0.56314.3517002300.192124650970】reelless pack.Traceability is based on identity of reels or reelless packs as0.600【15.258
20、60026110.21714017401100jmaintained and reported by the manufacturer.0.62015.7刀6280027910.23115078012000.70017.81794003530.294190100015005.3 Treatment-After stranding,strand shall be subjected toa continuous thermal-mechanical treatment to produce theprescribed mechanical properties.Temper colors whi
21、ch resultTABLE 2 Yield Strength Requirementsfrom the thermal-mechanical treatment are considered normalNominal Diameter ofMinimum Load at 1.0%for the finished appearance of this strand.Strand in.【mmInitial Load,Ibf kNExtension,Ibf kNGrade25017256.Mechanical Property Requirements0.2506.419004.08100I3
22、6.010.3137.914506.5)1305058.16.1 Tests for mechanical properties shall be conducted in0.3759.5120008.911800080.11accordance with Test Methods A1061/A1061M.0.43811.1270012.0124300108.110.50012.7360016.0132400144.16.2 Breaking Strength-The breaking strength of the fin-0.60015.21540024.048600216.2ished
23、 strand shall conform to the requirements prescribed inGrade27018600.3759.53230010.22070092.1Table 1.0.43811.1310013.827900124.10.50012.7413018.437170165.36.3 Yield Strength-Yield strength in pounds kNshall be0.52013.2450020.040500180.11measured at 1.0%extension under load.The minimum yield0.56314.3
24、1517023.0146530207.01strength shall be 90%of the breaking strength listed in Table0.60015.2586026.152740234.60.62015.7628027.956520251.411.Initial loads for the test and minimum yield strengths are0.70017.8794035.371500318.0listed in Table 2.6.3.1 The extension under load shall be measured by anexte
25、nsometer calibrated with the smallest division not largerTABLE 3 Diameter Relation Between Center and Outer Wiresthan 0.0001 in./in.0.0001 mm/mmof gage length.Nominal Diameter of Strand,in.Minimum Difference Between Center6.4 Elongation-The total elongation under load shall notWire Diameter and Diam
26、eter of Any【mmjOuter Wire,in.mmbe less than 3.5 using a gage length of not less than 24 in.Grade2501725600 mm.It shall be permissible to determine the total0.2506.40.0010.0251elongation value by adding,to the 1.0 yield extension,the0.3137.90.00150.03810.37519.510.0020.0511percent extension or moveme
27、nt between the jaws gripping the0.43811.10.00250.064strand after yield determination.The percent is calculated on0.50012.70.0030.0761the new base length of jaw-to-jaw distance.0.60015.20.0040.1021Grade 270 18606.5 Relaxation Properties-Strand shall have relaxation0.3759.530.0020.051Tlosses of not mo
28、re than 2.5 when initially loaded to 70 of0.43811.10.00250.0640.50012.70.0030.076specified minimum breaking strength or not more than 3.5%0.520【13.210.0030.0761when loaded to 80%of specified minimum breaking strength0.563I14.310.00350.0891of the strand after 1000 hours of testing.0.60015.20.0040.102
29、0.620I15.710.0040.10216.5.1 If required,relaxation evidence shall be provided from0.70017.80.00450.114the manufacturers records of tests on similarly dimensionedstrand of the same grade.7.Dimensions and Permissible Variations4.2.3 Weldless strand(8.1).4.2.4 Requirements for outside inspection(11.1).
30、7.1 The size of the finished strand shall be expressed as the4.2.5 Load-elongation curve(13.2),nominal diameter of the strand in inches millimetres.4.2.6 Packaging and package marking(Section 14).7.2 The diameter of the center wire of any strand shall be4.2.7 Supplementary Requirement S1,andlarger t
31、han the diameter of any outer wire in accordance with4.2.8 Other special requirements,if any.Table 3.2A416/A416M-17astrand on reels or in reelless packs shall be as agreed upon at14.2 When specified in the purchase order or contract,andthe time of purchase.The strand shall be well protected againstf
32、or direct procurement by or direct shipment to the U.S.mechanical injury in shipping as agreed upon at the time ofGovernment,marking for shipment,in addition to require-purchase.Each reel or reelless pack shall have two durable tagsments specified in the purchase order or contract,shall be insecurel
33、y fastened to it showing the length,size,grade,ASTMaccordance with Fed.Std.No.123 for civil agencies and MIL-designation A416 A416M,and the name of the manufacturer.STD-129 for military agencies.One tag shall be positioned where it will not be inadvertentlylost during transit,such as inside the core
34、 of a reelless pack.15.KeywordsThe other tag shall be placed on the outside of a reelless pack15.1 prestressed concrete;seven-wire strand(tendon);steelfor easy identification.wireSUPPLEMENTARY REQUIREMENTSThe following supplementary requirement shall apply only when specified in the purchase order o
35、rcontract.S1.BOND STRENGTH OF 0.600-IN.15.24-MM,GRADE 270 1860STRANDUSED IN PRESTRESSED GROUND ANCHORSS1.1 Bond Strengthminimum test value not less than 6800 lbf 30.2 kN.For anyS1.1.1 These requirements are not applicable to strand usedfuture retests,without changes in the manufacturing methodin pre
36、stressed concrete applications.and materials used,three tests shall be considered as adequate.S1.1.2 The results of bond-strength tests performed inS1.1.4 Retests-If the test specimens fail to satisfy S1.1.3,accordance with Test Method A981/A981M shall be submittedsix additional tests shall be perfo
37、rmed,and the results shallto the purchaser.The strand specimens,on which tests weresatisfy the acceptance criteria.Strand that fails the retests shallperformed,shall be from different lots and shall be represen-not be considered acceptable for use in prestressed groundtative for the strand ordered.a
38、nchors.S1.1.3 The average pull force from six pull tests,performedS1.1.5 Annual Tests-The pull tests shall be performedin accordance with Test Method A981/A981M,required toannually as a minimum or repeated when,in the opinion of thereach the 0.01-in.0.25-mmdisplacement described thereinmanufacturer,
39、a process change is made which is believedshall be at least 8000 Ibf 35.6 kN,with the individualcould decrease the bond strength of the strand.SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this standard since the last issue(A416/A416M-17)that may impact the use of this standard.(Approved December 1,2017.)(/Revised Section 4,11.1,and 13.1.Committee A0l has identified the location of selected changes to this standard since the last issue(A416/A416M-16)that may impact the use of this standard.(Approved May 1,2017.)(1)Revised 3.1.1.1.