ASTM A416 A416M-2010 Standard Specification for Steel Strand Uncoated Seven-Wire for Prestressed Concrete《预应力混凝土的未涂覆七股钢丝绞绳标准规范》.pdf

1、Designation: A416/A416M 10Standard Specification forSteel Strand, Uncoated Seven-Wire 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 revision, the year

2、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 Department of Defense.1. Scope*1.1 This specification covers two typ

3、es and two grades ofseven-wire, uncoated steel strand for use in pretensioned andpost-tensioned prestressed concrete construction. The twotypes of strand are low-relaxation and stress-relieved (normal-relaxation). Low-relaxation strand shall be regarded as thestandard type. Stress-relieved (normal-r

4、elaxation) strand willnot be furnished unless specifically ordered, or by arrangementbetween purchaser and supplier. Grade 1725 250 and Grade1860 270 have minimum ultimate strengths of 1725 MPa250 ksi and 1860 MPa 270 ksi, respectively, based on thenominal area of the strand.1.2 The values stated in

5、 either inch-pound units or SI unitsare to be regarded as standard. Within the text, the inch-poundunits are shown in brackets. The values stated in each systemare not exact equivalents; therefore, each system must be usedindependently of the other. Combining values from the twosystems may result in

6、 nonconformance with the specification.1.3 The supplementary requirements in S1 shall be specifiedfor 15.2-mm 0.600-in. diameter uncoated seven-wire steelstrand if needed for applications in prestressed ground anchors.2. Referenced Documents2.1 ASTM Standards:2A981 Test Method for Evaluating Bond St

7、rength for 15.2mm (0.6 in.) Diameter Prestressing Steel Strand, Grade270, Uncoated, Used in Prestressed Ground AnchorsA1061/A1061M Test Methods for Testing Multi-Wire SteelStrand2.2 U.S. Military Standards:3MIL-STD-129 Marking for Shipment and StorageMIL-STD-163 Steel Mill Products Preparation for S

8、hip-ment and Storage2.3 U.S. Federal Standard:3Fed. Std. No. 123 Marking for Shipments (Civil Agencies)3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 strand, na group of wires having a center wireenclosed tightly by six helically placed outer wires withuniform pitch of not le

9、ss than 12 and not more than 16 timesthe nominal diameter of the strand.3.1.1.1 DiscussionThe direction of lay may be eitherright- or left-hand, however, strands of different lays should notbe spliced together.4. Ordering Information4.1 Orders for seven-wire low-relaxation or stress-relieved(normal-

10、relaxation) strand under this specification should in-clude the following information:4.1.1 Quantity (metres feet),4.1.2 Diameter of strand,4.1.3 Grade of strand,4.1.4 Type of strand,4.1.5 Packaging,4.1.6 ASTM designation and year of issue, and4.1.7 Special requirements, if any.NOTE 1Atypical orderi

11、ng description is as follows: 25 600 m 84 000ft, 13 mm 0.5 in., Grade 1860 270 low-relaxation strand, in 3600-m12 000-ft reelless packs to ASTM A416/A416M _.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibilit

12、y of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved April 1, 2010. Published July 2010. Originallyapproved in 1957. Last previous edition approved in 2006 as A416 06. DOI:10.1520/A0416_A0416M-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM

13、Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, Bldg. 4, Section D,700 Robbins Ave., Philadelphia, PA 19111-5094.1*A Summary of Changes sect

14、ion appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Materials and Manufacture5.1 Base MetalThe base metal shall be carbon steel ofsuch quality that when drawn to wire, fabricated into strand,and

15、then thermally treated, shall have the properties andcharacteristics prescribed in this specification.5.2 WireThe wire from which the strand is to be fabri-cated shall be round and have a dry-drawn finish.NOTE 2This product is a composite of seven wires and is produced tomechanical properties only.

16、The chemical composition of all wires or anyindividual wire is not pertinent to this application, and heat identity is notnecessarily maintained. It is possible that wire from more than one heatmay be used in the manufacture of a reel or pack. Traceability is based onpack identity as maintained and

17、reported by the manufacturer.5.3 TreatmentAfter stranding, low-relaxation strand shallbe subjected to a continuous thermal-mechanical treatment toproduce the prescribed mechanical properties. For stress-relieved (normal-relaxation) strand, only thermal treatment isnecessary. Temper colors which resu

18、lt from the stress-relievingoperation are considered normal for the finished appearance ofthis strand.6. Mechanical Properties6.1 Tests for mechanical properties shall be conducted inaccordance with Test Methods A1061/A1061M. Low-relaxation strand shall also be tested as prescribed in TestMethods A1

19、061/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 kN pounds shall bemeasured at 1 % extension under load. The minimum yieldstrength shall be 90 % for low-relaxation strand and 85 %

20、forstress-relieved (normal-relaxation) strand of the breakingstrength listed in Table 1. Initial loads for the test and minimumyield strengths are listed in Table 2.6.3.1 The extension under load shall be measured by anextensometer calibrated with the smallest division not largerthan 0.0001 mm/mm 0.

21、0001 in./in. of gage length.6.4 ElongationThe total elongation under load shall notbe less than 3.5 % using a gage length of not less than 600 mm24 in. It shall be permissable to determine the total elonga-tion value by adding, to the 1.0 % yield extension, the percentextension or movement between t

22、he jaws gripping the strandafter yield determination. The percent is calculated on the newbase length of jaw-to-jaw distance.6.5 Relaxation PropertiesLow-relaxation strand shallhave relaxation losses of not more than 2.5 % when initiallyloaded to 70 % of specified minimum breaking strength or notmor

23、e than 3.5 % when loaded to 80 % of specified minimumbreaking strength of the strand after 1000 h tested under theconditions listed in 6.5.1 through 6.5.7.6.5.1 If required, relaxation evidence shall be provided fromthe manufacturers records of tests on similarly dimensionedstrand of the same grade.

24、6.5.2 The temperature of the test specimen shall be main-tained at 20 6 2C 68 6 3.5F.6.5.3 The test specimen shall not be subjected to loadingprior to the relaxation test.6.5.4 The initial load shall be applied uniformly over aperiod of not less than 3 min and not more than 5 min, and thegage length

25、 shall be maintained constant; load relaxationreadings shall commence 1 min after application of the totalload.6.5.5 Over-stressing of the test specimen during the loadingoperation shall not be permitted.6.5.6 The duration of the test shall be 1000 h or a shorterperiod of at least 200 h, provided it

26、 can be shown by recordsthat an extrapolation of the shorter period test results to 1000h will provide similar relaxation values as the full 1000 h test.6.5.7 The test gage length shall be at least 60 times thenominal diameter. If this gage length exceeds the capacity ofthe extensometer or testing m

27、achine, then it shall be permittedto substitute a gage length of 40 times the nomimal stranddiameter.7. Dimensions and Permissible Variations7.1 The size of the finished strand shall be expressed as thenominal diameter of the strand in millimetres inches.TABLE 1 Breaking Strength RequirementsStrand

28、Designation No. Diameter of Strand, mmin.Minimum BreakingStrength of Strand, kN lbfSteel Area of Strand,mm2in.2Weight of Strand kg/1000m lb/1000 ftGrade 1725 2506 6.4 0.250 40.0 9 000 23.2 0.036 182 1228 7.9 0.313 64.5 14 500 37.4 0.058 294 1979 9.5 0.375 89.0 20 000 51.6 0.080 405 27211 11.1 0.438

29、120.1 27 000 69.7 0.108 548 36713 12.7 0.500 160.1 36 000 92.9 0.144 730 49015 15.2 0.600 240.2 54 000 139.4 0.216 1094 737Grade 1860 2709 9.53 0.375 102.3 23 000 54.8 0.085 432 29011 11.11 0.438 137.9 31 000 74.2 0.115 582 39013 12.70 0.500 183.7 41 300 98.7 0.153 775 52013a 13.20 0.520 200.2 45 00

30、0 107.7 0.167 844 56814 14.29 0.563 230.0 51 700 123.9 0.192 970 65115 15.24 0.600 260.7 58 600 140.0 0.217 1102 74016 15.75 0.620 277.4 62 370 149.2 0.231 1173 778818 17.78 0.700 353.2 79 400 189.7 0.294 1487 1000A416/A416M 1027.2 The diameter of the center wire of any strand shall belarger than th

31、e diameter of any outer wire in accordance withTable 3.7.3 Permissible Variations in Diameter:7.3.1 All Grade 1725 250 strand shall conform to a sizetolerance of 60.40 mm 60.016 in. from the nominal diam-eter measured across the crowns of the wires.7.3.2 All Grade 1860 270 strand shall conform to a

32、sizetolerance of +0.65, 0.15 mm +0.026, 0.006 in. from thenominal diameter measured across the crowns of the wire.7.3.3 Variation in cross-sectional area and in unit stressresulting therefrom shall not be cause for rejection providedthat the diameter differences of the individual wires and thediamet

33、ers of the strand are within the tolerances specified.7.4 It shall be permitted to furnish, under this specification,specially dimensioned low-relaxation and stress-relieved(normal-relaxation) strands with nominal diameters up to 19mm 0.750 in. The breaking strength shall be defined, and theyield st

34、rength, as defined in 6.3, shall not be less than 90 % and85 % of the specified minimum breaking strength for low-relaxation and stress-relieved (normal relaxation) strands, re-spectively. All other requirements shall apply.8. Workmanship, Finish, and Appearance8.1 Joints:8.1.1 There shall be no str

35、and joints or strand splices in anylength of the completed strand unless specifically permitted bythe purchaser.8.1.2 During the process of manufacture of individual wiresfor stranding, welding shall be permitted only prior to or at thesize of the last thermal treatment, for example, patenting orcon

36、trolled cooling. There shall be no welds in the wire after ithas been drawn through the first die in the wire drawing exceptas provided in 8.1.3.8.1.3 During fabrication of the strand, butt-welded joints arepermitted in the individual wires, provided there shall not bemore than one such joint in any

37、 45-m 150-ft section of thecompleted strand.TABLE 2 Yield Strength RequirementsStrandDesignationNo.Nominal Diameterof Strandmm in.Initial Load,kN lbfMinimum Load at 1 % Extension,kN lbfLow-Relaxation Normal-RelaxationGrade 1725 2506 6.4 0.250 4.0 900 36.0 8 100 34.0 7 6508 7.9 0.313 6.5 1 450 58.1 1

38、3 050 54.7 12 3009 9.5 0.375 8.9 2 000 80.1 18 000 75.6 17 00011 11.1 0.438 12.0 2 700 108.1 24 300 102.3 23 00013 12.7 0.500 16.0 3 600 144.1 32 400 136.2 30 60015 15.2 0.600 24.0 5 400 216.2 48 600 204.2 45 900Grade 1860 2709 9.53 0.375 10.2 2 300 92.1 20 700 87.0 19 55011 11.11 0.438 13.8 3 100 1

39、24.1 27 900 117.2 26 35013 12.70 0.500 18.4 4 130 165.3 37 170 156.1 35 10013a 13.20 0.520 20.0 4 500 180.1 40 500 170.1 38 25014 14.29 0.563 23.0 5 170 207.0 46 530 195.5 43 95015 15.24 0.600 26.1 5 860 234.6 52 740 221.5 49 80016 15.75 0.620 27.7 6 237 249.7 56 133 235.9 53 01518 17.78 0.700 35.3

40、7 940 318.0 71 500 300.2 67 500TABLE 3 Diameter Relation Between Center and Outer WiresStrandDesignation No.Nominal Diameter of Strands,mm in.Minimum Difference BetweenCenter Wire Diameter and Diameterof Any Outer Wire, mm in.Grade 1725 2506 6.4 0.250 0.025 0.0018 7.9 0.313 0.038 0.00159 9.5 0.375 0

41、.051 0.00211 11.1 0.438 0.064 0.002513 12.7 0.500 0.076 0.00315 15.2 0.600 0.102 0.004Grade 1860 2709 9.53 0.375 0.0508 0.00211 11.11 0.438 0.0635 0.002513 12.70 0.500 0.0762 0.00313a 13.20 0.520 0.0762 0.00314 14.29 0.563 0.0889 0.003515 15.24 0.600 0.1016 0.00416 15.75 0.620 0.1016 0.00418 17.78 0

42、.700 0.1143 0.0045A416/A416M 1038.1.4 When specifically ordered as “Weldless,” a productfree of welds shall be furnished. When “Weldless” is specified,the strand is produced as one continuous length with no weldsas allowed by 8.1.3.8.2 The finished strand shall be uniform in diameter andshall be fre

43、e of imperfections not consistent with good com-mercial strand practices.8.3 When the strand is cut without seizings, the wire shallnot fly out of position. If any wire flies out of position and canbe replaced by hand, the strand shall be considered satisfactory.8.4 The strand shall not be oiled or

44、greased. Slight rusting,provided it is not sufficient to cause pits visible to the unaidedeye, shall not be cause for rejection.NOTE 3Guidance for evaluating the degree of rusting on prestressedconcrete strand is presented in Sason.49. Sampling9.1 Test specimens cut from either end of the strand pac

45、kageare permitted.Any specimen found to contain a wire joint shallbe discarded and a new specimen obtained.10. Number of Tests10.1 One specimen for test shall be taken from each 18-Mg20-ton production lot of finished strand, and tested forbreaking strength, yield strength, and elongation.11. Inspect

46、ion11.1 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 to

47、shipment,unless otherwise agreed upon at the time of purchase, and shallbe so conducted as not to interfere unnecessarily with theoperation of the works.NOTE 4The purchaser should state, at the time of order, whetheroutside inspection is required or waived.12. Rejection12.1 Failure of any test speci

48、men to comply with therequirements of the specification shall constitute grounds forrejection of the lot represented by the specimen.12.2 The lot shall be resubmitted for inspection by testing aspecimen from each reel or pack and sorting out non-conforming material.12.3 In case there is a reasonable doubt in the initial testingas to the ability of the strand to meet any requirement of thisspecification, two additional tests shall be made on a specimenof strand from the same reel or pack, and if fai