1、Designation: A910/A910M 16Standard Specification forUncoated, Weldless, 2-Wire and 3-Wire Steel Strand forPrestressed Concrete1This standard is issued under the fixed designation A910/A910M; the number immediately following the designation indicates the yearof original adoption or, in the case of re
2、vision, 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.1. Scope*1.1 This specification covers two types and two grades of2-wire and 3-wire, uncoated steel strand for
3、 use in prestressedconcrete construction. The two types of strand are low-relaxation and stress-relieved (normal-relaxation). Low-relaxation is to be regarded as the standard type. Stress-relieved (normal-relaxation) strand will not be furnished unlessspecifically ordered. The two grades are 250 172
4、5 and 2701860. Grades 250 1725 and 270 1860 have minimumtensile strengths of 250 ksi 1725 MPa and 270 ksi 1860MPa respectively, based on the nominal area of the strand.1.2 This specification is applicable for orders in eitherinch-pound units (as Specification A910) or in SI units (asSpecification A9
5、10M).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 are not exact equivalents; therefore, each system shallbe used independently of the other. Combining values
6、from thetwo systems may result in non-conformance with the specifi-cation.2. Referenced Documents2.1 ASTM Standard:2A1061/A1061M Test Methods for Testing Multi-Wire SteelPrestressing Strand2.2 U.S. Military Standard:3MIL-STD-129 Marking for Shipment and Storage2.3 Federal Standard:3Fed. Std. No. 123
7、 Marking for Shipments (Civil Agencies)3. Terminology3.1 Definition of Term Specific to This Specification:3.1.1 strand, nEither two or three wires helically woundaround each other with uniform pitch not less than 12 and notmore than 16 times the nominal diameter of the strand.3.1.1.1 DiscussionThe
8、direction of lay is either right-handed or left-handed.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specifyall requirements that are necessary for material ordered to thisspecification. Such requirements shall include, but are notlimited to, the following:4.1.1 Quant
9、ity (feet metres),4.1.2 Nominal diameter and description of strand (Table 1),4.1.3 Number of wires (2 or 3),4.1.4 Grade,4.1.5 Type of strand (low-relaxation or stress-relieved (nor-mal relaxation),4.1.6 Inspection (11.1),4.1.7 Load-elongation curve (13.2),4.1.8 Packaging (14.1), and4.1.9 ASTM design
10、ation and year of issue.5. Materials and Manufacture5.1 Base MetalThe base metal shall be carbon steel ofsuch quality that when drawn to wire, fabricated into strandand then thermally treated, it shall have the properties andcharacteristics prescribed in this specification.5.2 WireThe wire from whic
11、h the strand is to be fabricatedshall be round and have a dry-drawn finish.NOTE 1This product is a composite of two or three wires and isproduced only to meet the prescribed mechanical properties, of which thechemical composition of all wires or any individual wire is not pertinentto this applicatio
12、n, and heat identity is not necessarily maintained. It ispossible that wire from more than one heat may be used in themanufacture of a reel or reelless pack. Traceability is based on the identityof reels or reelless packs as maintained and reported by the manufacturer.5.3 TreatmentAfter stranding, l
13、ow-relaxation strand shallbe subjected to a continuous thermo-mechanical treatment toproduce the prescribed mechanical properties. For stress-relieved (normal-relaxation) strand, only thermal treatment is1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and
14、 Related Alloys and is the direct responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved Dec. 1, 2016. Published January 2017. Originallyapproved in 1992. Last previous edition approved in 2012 as A910/A910M 12.DOI: 10.1520/A0910_A0910M-16.2For referenced ASTM standards
15、, 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.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol
16、St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.*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 StatesThis international standard was developed in accor
17、dance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1necessary. Temper colors that re
18、sult from the stress-relievingoperation are considered normal for the finished appearance ofthis strand.6. Mechanical Property Requirements6.1 Tests for mechanical properties shall be conducted inaccordance with Test Methods A1061/A1061M. Low-relaxation strand shall also be tested as prescribed in T
19、estMethods A1061/A1061M.6.2 Breaking StrengthThe breaking strength of the fin-ished strand shall conform to the requirements prescribed inTable 1.6.3 Yield StrengthYield strength in lbs kN shall bemeasured at 1 % extension under load in accordance with thetest procedure delineated in Test Methods A1
20、061/A1061M,Section 9.1. The minimum yield strength shall be 90 % forlow-relaxation strand and 85 % for stress-relieved (normal-relaxation) strand of the breaking strength listed in Table 1.Initial loads for the test and minimum yield strengths are listedin Table 2.6.3.1 The extension under load shal
21、l be measured by anextensometer calibrated with the smallest division not largerthan 0.0001 in./in. 0.0001 mm/mm of gage length.6.4 ElongationThe total elongation under load shall bedetermined in accordance with Test Methods A1061/A1061M,Section 9.2. The total elongation under load shall not be less
22、than 3.5 % using a gage length of not less than 24 in. 600mm. It shall be permissible to determine the total elongationvalue by adding to the 1.0 % yield extension the percentextension or movement between the jaws gripping the strandafter yield determination. The percent is calculated on the newbase
23、 length of jaw-to-jaw distance.6.5 Relaxation PropertiesLow-relaxation strand shallhave relaxation losses of not more than 2.5 % when initiallyTABLE 1 Breaking Strength RequirementsDescription and Nominal Diameter of StrandBreaking Strength ofStrandSteel Area ofStrandWeight Mass ofStrandin. mmDescri
24、ptionNominalDiameterDescriptionNominalDiameterlbf kN in.2mm2 lbs/1000 ft kg/1000 mGRADE 250 1725 MPa2 0.114 0.228 2 2.90 5.8 5000 22.2 0.020 13.2 69.9 104.03 0.089 0.189 3 2.25 4.8 4750 21.1 0.019 12.0 63.3 94.23 0.095 0.205 3 2.40 5.2 5250 23.4 0.021 13.6 71.9 107.03 0.114 0.244 3 2.90 6.2 7750 34.
25、5 0.031 19.8 104.0 155.03 0.118 0.256 3 3.00 6.5 8250 36.7 0.033 21.3 112.0 167.03 0.138 0.295 3 3.50 7.5 11 250 50.0 0.045 29.0 153.0 228.03 0.158 0.340 3 4.00 8.6 14 500 64.5 0.058 37.4 200.6 298.4GRADE 270 1860 MPa2 0.114 0.228 2 2.90 5.8 5400 24.0 0.020 13.2 69.9 104.03 0.089 0.189 3 2.25 4.8 51
26、30 22.8 0.019 12.0 63.3 94.23 0.095 0.205 3 2.40 5.2 5670 25.2 0.021 13.6 71.9 107.03 0.114 0.244 3 2.90 6.2 8370 37.2 0.031 19.8 104.0 155.03 0.118 0.256 3 3.00 6.5 8910 39.6 0.033 21.3 112.0 167.03 0.138 0.295 3 3.50 7.5 12 150 54.0 0.045 29.0 153.0 228.03 0.158 0.340 3 4.00 8.6 15 660 69.7 0.058
27、37.4 200.6 298.4TABLE 2 Yield Strength RequirementsDescription and Nominal Diameter of StrandInitial LoadMinimum Load at 1 % Extensionin. mmStress-Relieved(Normal-Relaxation)Low-RelaxationDescriptionNominalDiameterDescriptionNominalDiameterlbf kN lbf kN lbf kNGRADE 250 1725 MPa2 0.114 0.228 2 2.90 5
28、.8 500 2.2 4250 18.9 4500 20.03 0.089 0.189 3 2.25 4.8 475 2.1 4038 18.0 4275 19.03 0.095 0.205 3 2.40 5.2 525 2.3 4463 20.0 4725 21.03 0.114 0.244 3 2.90 6.2 775 3.5 6588 29.3 6975 31.03 0.118 0.256 3 3.00 6.5 825 3.7 7013 32.2 7425 33.03 0.138 0.295 3 3.50 7.5 1250 5.0 9563 42.5 10 125 45.03 0.158
29、 0.340 3 4.00 8.5 1450 6.5 12 325 54.8 13 050 11.7GRADE 270 1860 MPa2 0.114 0.228 2 2.90 5.8 540 2.4 4590 20.4 4860 21.63 0.089 0.189 3 2.25 4.8 513 2.3 4360 19.4 4617 20.53 0.095 0.205 3 2.40 5.2 567 2.5 4820 21.4 5103 22.73 0.114 0.244 3 2.90 6.2 837 3.7 7115 31.6 7533 33.53 0.118 0.256 3 3.00 6.5
30、 891 4.0 7574 33.7 8019 36.03 0.138 0.295 3 3.50 7.5 125 5.4 10 328 45.9 10 125 45.03 0.158 0.340 3 4.00 8.6 566 7.0 13 311 59.2 14 094 62.7A910/A910M 162loaded to 70 % of specified minimum breaking strength or notmore than 3.5 % when loaded to 80 % of specified minimumbreaking strength of the stran
31、d after 1000 h tested in accor-dance with the specific procedures in Test Methods A1061/A1061M, Section 9.4.6.5.1 If required, relaxation evidence shall be provided fromthe manufacturers records of tests on similarly dimensionedstrand of the same grade.7. Dimensions and Permissible Variations7.1 The
32、 size of the finished strand shall be expressed as thenominal diameter of the strand in in. mm.7.2 Variations in individual wire diameters shall not because for rejection provided that the other requirements of thisspecification are met.7.3 Specially-Dimensioned Strand:7.3.1 It shall be permitted to
33、 furnish, under thisspecification, strands with nominal diameters that are differentthan those listed in Table 1 and Table 2. The breaking strengthshall be defined, and the yield strength, as defined in 6.3, shallnot be less than 90 % and 85 % of the specified minimumbreaking strength for low-relaxa
34、tion and stress-relieved(normal-relaxation) strand, respectively.All other requirementsshall apply.7.4 Permissible Variations in Diameter:7.4.1 All Grade 250 1725 strand shall conform to a sizetolerance of 60.016 in. 60.41 mm from the diametermeasured across the crowns of the wires (2-wire strand on
35、ly).For 3-wire strand, the diameter is that diameter of a circlewhich can be tangentially circumscribed around the 3 wires.This can be confirmed by comparing the individual wirediameters in the strand to those listed in Table 1 and Table 2.7.4.2 All Grade 270 1860 strand shall conform to a sizetoler
36、ance of +0.026 in., 0.006 in. +0.66 mm, 0.15 mmfrom the nominal diameter measured across the crowns of thewires (2-wire strand only). For 3-wire strand, the nominaldiameter is that diameter of a circle which can be tangentiallycircumscribed around the 3 wires. This can be confirmed bycomparing the i
37、ndividual wire diameters in the strand to thoselisted in Table 1 and Table 2.8. Workmanship, Finish and Appearance8.1 Joints:8.1.1 There shall be no strand splices in any length of thecompleted strand.8.1.2 There shall be no wire welds made in the finishedstrands. During manufacturing of individual
38、wires forstranding, welding is permitted only prior to or at the size ofthe last thermal treatment (for example, patenting or controlcooling). There shall be no welds in the wire after it has beendrawn through the first die in wire drawing.8.2 When the strand is cut without seizings, the wire shalln
39、ot fly out of position. If any wire flies out of position and canbe replaced by hand, the strand will be considered satisfactory.8.3 The strand shall not be oiled or greased. Slight rusting,provided it is not sufficient to cause pits visible to a person withnormal or corrected vision, shall not be c
40、ause for rejection.9. Sampling9.1 Test specimens cut from either end of the reel or reellesspack are permitted.10. Number of Tests10.1 One test specimen shall be taken from each 30-ton27-tonne production lot of finished strand, and tested forbreaking strength, yield strength, and elongation.11. Insp
41、ection11.1 If outside inspection is required, the manufacturer shallafford the inspector representing the purchaser all reasonablefacilities to satisfy that the material is being furnished inaccordance with this specification. All tests and inspectionsshall be made at the place of manufacture prior
42、to shipment,unless otherwise agreed upon at the time of purchase, and shallbe so conducted as not to interfere unnecessarily with themanufacturers operations.12. Rejection and Retesting12.1 Failure of any test specimen to comply with therequirements of the specification shall constitute grounds forr
43、ejection of the lot represented by the specimen.12.2 The lot shall be resubmitted for inspection by testing aspecimen from each reel or reelless pack and sorting outnon-conforming material.12.3 In case there is a reasonable doubt in the initial testingas to the ability of the strand to meet any requ
44、irement of thisspecification, two additional tests shall be made on a specimenof strand from the same reel or reelless pack, and if failureoccurs in either of these tests, the strand shall be rejected.13. Certification13.1 If outside inspection is not required, a manufacturerscertification that the
45、material has been tested in accordancewith and meets the requirements of this specification shall bethe basis of acceptance of the material. The certification shallinclude Specification A910/A910M, year-date of issue, andrevision letter, if any.13.2 The manufacturer shall, when requested in the pur-
46、chase order or contract, furnish a representative load-elongation curve for each size and grade of strand shipped.13.3 When the modulus of elasticity of a 2-wire or 3-wirestrand is provided, the cross-sectional area used to calculate themodulus shall also be provided. The area provided in thecertifi
47、cation shall be the area used to calculate the modulus ofelasticity.13.4 A material test report, certification or inspection, orsimilar document printed from or used in electronic form froman electronic data interchange (EDI) transmission shall beregarded as having the same validity as a counterpart
48、 printed inthe certifiers facility. The content of the EDI transmitteddocument shall meet the requirements of the invoked ASTMstandard(s) and conform to any existing EDI agreement be-tween the purchaser and the manufacturer. Notwithstanding theabsence of a signature, the organization submitting the EDItransmission is responsible for the content of the report.A910/A910M 163NOTE 2The industry definition for EDI, as i
