1、Designation: A416/A416M 16A416/A416M 17Standard 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
2、revision, 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. Scope*1.1 This spec
3、ification covers two grades of low-relaxation, seven-wire steel strand for use in prestressed concrete construction.Grade 250 1725 and Grade 270 1860 have minimum tensile strengths of 250 ksi 1725 MPa and 270 ksi 1860 MPa,respectively, based on the nominal area of the strand.1.2 Asupplementary requi
4、rement (S1) is provided for use where bond strength testing of 0.600-in. 15.24-mm diameter Grade270 1860 strand for applications in prestressed ground anchors is required by the purchaser. The supplementary requirementapplies only when specified in the purchase order.1.3 The text of this specificati
5、on contains notes or footnotes, or both, that provide explanatory material. Such notes andfootnotes do not contain any mandatory information.1.4 This specification is applicable for orders in either inch-pound units (as Specification A416) or in SI units (as SpecificationA416M).1.5 The values stated
6、 in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI unitsare shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the two systems
7、may result in non-conformance with the specification.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby
8、the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A981/A981M Test Method for Evaluating Bond Strength for 0.600-in. 15.24-mm Diameter Steel Prestressing Strand, Grade270 1860, Uncoated, Used in Prestressed Ground AnchorsA1061/A1061M T
9、est Methods for Testing Multi-Wire Steel Prestressing Strand2.2 U.S. Military Standard:3MIL-STD-129 Marking for Shipment and Storage2.3 U.S. Federal Standard:3Fed. Std. No. 123 Marking for Shipments (Civil Agencies)3. Terminology3.1 Definition of Term Specific to This Specification:3.1.1 strand, na
10、group of wires having a center wire enclosed tightly by six helically placed outer wires with uniform pitchof not less than 12 and not more than 16 times the nominal diameter of the strand.1 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys
11、 and is the direct responsibility of Subcommittee A01.05on Steel Reinforcement.Current edition approved March 1, 2016May 1, 2017. Published March 2016May 2017. Originally approved in 1957. Last previous edition approved in 20152016 asA416/A416M 15.A416/A416M 16. DOI: 10.1520/A0416_A0416M-16.10.1520/
12、A0416_A0416M-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from Standardization Documents Or
13、der Desk, DODSSP, Bldg. 4, Section D, DLA Document Services, Building 4/D, 700 Robbins Ave., Philadelphia, PA19111-5098, http:/dodssp.daps.dla.mil.19111-5094, http:/quicksearch.dla.mil.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of
14、 what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered
15、 the official document.*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 States13.1.1.1 DiscussionThe direction of lay may be is either right-right-handed or left-hand.left-hande
16、d.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specify all requirements that are necessary for material ordered under thisspecification. Such requirements to be considered include, but are not limited to, the following:4.1.1 Quantity (feet metres),4.1.2 Nominal diame
17、ter of strand,4.1.3 Grade of strand,4.1.4 Specially dimensioned strand (7.4), if desired,4.1.5 Weldless, if desired (8.1),4.1.6 Outside inspection, if required (11.1),4.1.7 Load-elongation curve, if desired (13.2),4.1.8 Packaging (14.1),4.1.9 Supplementary Requirement S1, if desired, and4.1.10 ASTM
18、designation A416 A416M and year of issue.5. Materials and Manufacture5.1 Base MetalThe base metal shall be carbon steel of such quality that when drawn to wire, fabricated into strand, and thenthermally treated, shall have the properties and characteristics prescribed in this specification.5.2 WireT
19、he wire from which the strand is to be fabricated shall be round and have a dry-drawn finish.NOTE 1This product is a composite of seven wires and is produced only to meet the prescribed mechanical properties. The chemical compositionof all wires or any individual wire is not pertinent to this applic
20、ation, and heat identity is not necessarily maintained. It is possible that wire from morethan one heat may be used in the manufacture of a reel or reelless pack. Traceability is based on identity of reels or reelless packs as maintained andreported by the manufacturer.5.3 TreatmentAfter stranding,
21、strand shall be subjected to a continuous thermal-mechanical treatment to produce theprescribed mechanical properties. Temper colors which result from the thermal-mechanical treatment are considered normal for thefinished appearance of this strand.6. Mechanical Property Requirements6.1 Tests for mec
22、hanical properties shall be conducted in accordance with Test Methods A1061/A1061M.6.2 Breaking StrengthThe breaking strength of the finished strand shall conform to the requirements prescribed in Table 1.6.3 Yield StrengthYield strength in pounds kN shall be measured at 1.0 % extension under load.
23、The minimum yield strengthshall be 90 % of the breaking strength listed in Table 1. Initial loads for the test and minimum yield strengths are listed in Table2.6.3.1 The extension under load shall be measured by an extensometer calibrated with the smallest division not larger than0.0001 in./in. 0.00
24、01 mm/mm of gage length.TABLE 1 Breaking Strength RequirementsNominal Diameterof Strand, in. mmMinimum BreakingStrength ofStrand, lbf kNSteel Area ofStrand, in.2 mm2Weight Mass ofStrand lb/1000 ftkg/1000 mGrade 250 17250.250 6.4 9 000 40.0 0.036 23 122 1820.313 7.9 14 500 64.5 0.058 37 197 2940.375
25、9.5 20 000 89.0 0.080 52 272 4050.438 11.1 27 000 120 0.108 69.7 367 5480.500 12.7 36 000 160 0.144 92.9 490 7300.600 15.2 54 000 240 0.216 139 737 1090Grade 270 18600.375 9.53 23 000 102 0.085 55 290 4300.438 11.1 31 000 138 0.115 74.2 390 5800.500 12.7 41 300 184 0.153 98.7 520 7800.520 13.2 45 00
26、0 200 0.167 108 570 8400.563 14.3 51 700 230 0.192 124 650 9700.600 15.2 58 600 261 0.217 140 740 11000.620 15.7 62 800 279 0.231 150 780 12000.700 17.8 79 400 353 0.294 190 1000 1500A416/A416M 1726.4 ElongationThe total elongation under load shall not be less than 3.5 % using a gage length of not l
27、ess than 24 in. 600mm. It shall be permissible to determine the total elongation value by adding, to the 1.0 % yield extension, the percent extensionor movement between the jaws gripping the strand after yield determination. The percent is calculated on the new base length ofjaw-to-jaw distance.6.5
28、Relaxation PropertiesStrand shall have relaxation losses of not more than 2.5 % when initially loaded to 70 % of specifiedminimum breaking strength or not more than 3.5 % when loaded to 80 % of specified minimum breaking strength of the strandafter 1000 hours of testing.6.5.1 If required, relaxation
29、 evidence shall be provided from the manufacturers records of tests on similarly dimensioned strandof the same grade.7. Dimensions and Permissible Variations7.1 The size of the finished strand shall be expressed as the nominal diameter of the strand in inches millimetres.7.2 The diameter of the cent
30、er wire of any strand shall be larger than the diameter of any outer wire in accordance with Table3.TABLE 2 Yield Strength RequirementsNominal Diameter ofStrand in. mm Initial Load, lbf kNMinimum Load at 1.0 %Extension, lbf kNGrade 250 17250.250 6.4 900 4.0 8 100 36.00.313 7.9 1 450 6.5 13 050 58.10
31、.375 9.5 2 000 8.9 18 000 80.10.438 11.1 2 700 12.0 24 300 108.10.500 12.7 3 600 16.0 32 400 144.10.600 15.2 5 400 24.0 48 600 216.2Grade 270 18600.375 9.53 2 300 10.2 20 700 92.10.438 11.1 3 100 13.8 27 900 124.10.500 12.7 4 130 18.4 37 170 165.30.520 13.2 4 500 20.0 40 500 180.10.563 14.3 5 170 23
32、.0 46 530 207.00.600 15.2 5 860 26.1 52 740 234.60.620 15.7 6 280 27.9 56 520 251.40.700 17.8 7 940 35.3 71 500 318.0TABLE 3 Diameter Relation Between Center and Outer WiresNominal Diameter of Strand, in.mmMinimum Difference Between CenterWire Diameter and Diameter of AnyOuter Wire, in. mmGrade 250
33、17250.250 6.4 0.001 0.0250.313 7.9 0.0015 0.0380.375 9.5 0.002 0.0510.438 11.1 0.0025 0.0640.500 12.7 0.003 0.0760.600 15.2 0.004 0.102Grade 270 18600.375 9.53 0.002 0.0510.438 11.1 0.0025 0.0640.500 12.7 0.003 0.0760.520 13.2 0.003 0.0760.563 14.3 0.0035 0.0890.600 15.2 0.004 0.1020.620 15.7 0.004
34、0.1020.700 17.8 0.0045 0.114A416/A416M 1737.3 Permissible Variations in Diameter:7.3.1 All Grade 250 1725 strand shall conform to a size tolerance of 60.016 in. 60.40 mm from the nominal diametermeasured across the crowns of the wires.7.3.2 All Grade 270 1860 strand shall conform to a size tolerance
35、 of +0.026, 0.006 in. +0.65, 0.15 mm from the nominaldiameter measured across the crowns of the wires.7.3.3 Variation in cross-sectional area and in unit stress resulting therefrom shall not be cause for rejection provided that thediameter differences of the individual wires and the diameters of the
36、 strand are within the tolerances specified.7.4 It shall be permitted to furnish specially dimensioned strands with nominal diameters up to 0.750 in. 19 mm. The breakingstrength shall be defined, and the yield strength, as defined in 6.3, shall not be less than 90 % of the specified minimum breaking
37、strength. All other requirements shall apply.8. Workmanship, Finish, and Appearance8.1 Joints:8.1.1 There shall be no strand joints or strand splices in any length of the finished strand unless specifically permitted by thepurchaser.8.1.2 During the process of manufacture of individual wires for str
38、anding, welding shall be permitted only prior to or at the sizeof the last thermal treatment, for example, patenting or controlled cooling. There shall be no welds in the wire after it has beendrawn through the first die in the wire drawing except as provided in 8.1.3.8.1.3 During fabrication of the
39、 strand, butt-welded joints are permitted in the individual wires, provided there shall not be morethan one such joint in any 150-ft 45-m section of the finished strand.8.1.4 When specifically ordered as “Weldless,” a product free of welds shall be furnished. When “Weldless” is specified, thestrand
40、is produced as one continuous length with no welds as allowed by 8.1.3.8.2 The finished strand shall be uniform in diameter and shall be free of imperfections.8.3 When the strand is cut without seizings, the wire shall not fly out of position. If any wire flies out of position and can bereplaced by
41、hand, the strand shall be considered satisfactory.8.4 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 cause for rejection.NOTE 2Guidance for evaluating the degree of rusting on pres
42、tressed concrete strand is presented in Sason.49. Sampling9.1 Test specimens cut from either end of the reel or reelless pack are permitted. Any specimen found to contain a wire jointshall be discarded and a new specimen obtained.10. Number of Tests10.1 One test specimen shall be taken from each 30-
43、ton 27-tonne production lot of finished strand, and tested for breakingstrength, yield strength, and elongation.11. Inspection11.1 If outside inspection is required, the manufacturer shall afford the inspector representing the purchaser reasonable accessto the facilities, which concern the manufactu
44、re of the material ordered, to satisfy the inspector that the material is being furnishedin accordance with this specification. All tests and inspections shall be made at the place of manufacture prior to shipment, unlessotherwise agreed upon at the time of purchase, and shall be so conducted as not
45、 to interfere unnecessarily with the manufacturersoperations.12. Rejection12.1 Failure of any test specimen to comply with the requirements of the specification shall constitute grounds for rejection ofthe production lot represented by the specimen.12.2 The production lot shall be resubmitted for in
46、spection by testing a specimen from each reel or reelless pack and sortingout non-conforming material.12.3 If there is a reasonable doubt in the initial testing as to the ability of the strand to meet any requirement of this specification,two additional tests shall be made on specimens of strand fro
47、m the same reel or reelless pack, and if failure occurs in either ofthese tests, the strand shall be rejected.4 Sason, A.S., “Evaluation of Degree of Rusting on Prestressed Concrete Strand,Strand,” PCI Journal, Precast/Prestressed Concrete Institute, Vol 37, No. 3, MayJune1992, pp. 2530. Reprints of
48、 this paper are available from the Precast/Prestressed Concrete Institute, 200 West Adams St., Suite 2100, Chicago, IL 60606.A416/A416M 17413. Certification13.1 If outside inspection is not required, a manufacturers certification that the material has been tested in accordance with andmeets the requirements of this specification shall be the basis of acceptance of the material. The certification shall include thespecification number, year of issue, and revision letter, if any.13.2 When requested in the purchase order or contra
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