1、Designation: A648 11Standard Specification forSteel Wire, Hard Drawn for Prestressing Concrete Pipe1This standard is issued under the fixed designation A648; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers two classes of uncoated, high-strength, hard-drawn steel wire for use in the manufacture ofprestressed c
3、oncrete pipe. In application, the wire is helicallywrapped on the pipe maintaining tension by mechanical meansnot including drawing dies.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided
4、for information onlyand are not considered standard.1.3 Supplementary requirements describe hydrogen em-brittlement resistance test acceptance criteria.1.4 The following caveat pertains only to the test methodportions of this specification, 6.2.3 and 6.4.3: This standarddoes not purport to address t
5、he safety concerns, if any,associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definiti
6、ons for Mechanical Testingof Steel ProductsA510 Specification for General Requirements for WireRods and Coarse Round Wire, Carbon SteelA700 Practices for Packaging, Marking, and Loading Meth-ods for Steel Products for ShipmentA1032 Test Method for Hydrogen Embrittlement Resis-tance for Steel Wire Ha
7、rd Drawn Used for PrestressingConcrete PipeE328 Test Methods for Stress Relaxation for Materials andStructures2.2 ANSI Standard:3C 304 Standard for Design of Prestressed Concrete CylinderPipe3. Ordering Information3.1 Orders for material to this specification should includethe following information:
8、3.1.1 Quantity (weight),3.1.2 Name of material (hard-drawn steel wire for prestress-ing concrete pipe),3.1.3 Wire diameter (see Table 1),3.1.4 Class (see Table 1),3.1.5 Packaging (see Section 11),3.1.6 ASTM designation and year of issue, and3.1.7 Special requirements, if any (see Supplementary Re-qu
9、irements).NOTE 1A typical ordering description is as follows: 100 000-lb,Hard-Drawn Steel Wire for Prestressing Concrete Pipe, 0.192 in. indiameter, Class III, 1500-lb coils, to ASTM A648 _.4. Manufacture4.1 The steel shall be made by the electric-arc furnace,open-hearth, basic-oxygen, or process.4.
10、2 The steel shall be free of injurious piping and unduesegregation.4.3 The wire shall be cold drawn to produce the prescribedmechanical properties. The wire manufacturer shall take de-pendable precautions during wire drawing to preclude detri-mental strain aging of the wire.NOTE 2Allowing wire to re
11、main at elevated temperatures, such as400F (204C) for more than5sor360F (182C) for more than 20 s, canresult in detrimental strain aging of the wire. Detrimentally strain-aged1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the di
12、rect responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved Jan. 1, 2011. Published January 2011. Originallyapproved in 1972. Last previous edition approved in 2004 as A648 04a. DOI:10.1520/A0648-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, o
13、rcontact 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 American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1*A S
14、ummary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.wire typically has reduced ductility and increased susceptibility tohydrogen embrittlement.4.4 There shall be no welds or jo
15、ints in the finished wire.Any welds or joints made during manufacture to enablecontinuity of operations shall be removed.5. Chemical Requirements5.1 The heat analysis of the steel shall conform to thechemical requirements specified in Table 2.5.2 An analysis of each heat of steel shall be furnished
16、bythe manufacturer showing the percentages of all the elementsspecified in Table 2. The wire shall be subject to permissiblevariation for product analysis specified in Specification A510,Table 7.6. Mechanical RequirementsNOTE 3Mechanical requirements are applicable only prior to orduring pipe manufa
17、cture.6.1 Test SpecimensWire specimens for tensile and tor-sion tests shall be taken from either end of a coil but must berepresentative of that coils wire drawing conditions withregard to wire temperature.6.2 Tension Tests:6.2.1 Tensile RequirementsTensile requirements shallconform to those prescri
18、bed in Table 1 for the specified sizeand class.6.2.2 Number of TestsOne test specimen shall be takenfrom each coil.6.2.3 Test MethodTension tests shall be made in accor-dance with Test Methods and Definitions A370, Annex A4.Tension test reports shall include the coil number tested, themeasured wire
19、diameter, and the measured breaking strength.6.2.4 Reduction-of-Area TestThe reduction of area re-quirement for the specimens used for the tension test in 6.1shall be a minimum of 35 % for 0.192 in. (4.88 mm) wire and30 % for larger wire as described and tested in accordance withTest Methods and Def
20、initions A370, Annex A4.6.3 Relaxation Test:6.3.1 Number of TestsRelaxation test results shall beprovided for purposes of qualifying the procedures used tomanufacture wire for prestressing pipe. Relaxation test resultsshall include one specimen from a minimum of three coils ofwire from the same or d
21、ifferent heats of steel where the wirespecimen are of the same nominal size, the same class, andmanufactured using the same drawing machine and drawingprocedures. It shall be permissible to provide the relaxation testresults from the wire manufacturers historical records.6.3.2 Test MethodWire shall
22、be tested as described in TestMethods E328.6.3.3 Conditions of TestsThe conditions of the tests are:6.3.3.1 At least one of the tests performed shall have aduration of 1000 h minimum, and all other tests shall have aduration of at least 200 h. Measurements shall be made andrecorded for at least five
23、 data points during each time intervalof (1) 0 to 10 h, (2) 10 to 100 h, and (3) 100 to 1000 h, exceptthat, if a test is terminated in less than 1000 h, measurementsshall be made for at least two data points in the third interval.For tests terminated in less than 1000 h, the expected relaxationof th
24、e specimen at 1000 h shall be determined from the linearregression curve of stress loss on a logarithm time scale.6.3.3.2 The temperature of the test specimen shall bemaintained at 68 6 3.5F (20 6 2C).6.3.3.3 The test specimen shall not be subjected to loading,including specimen straightening, prior
25、 to the relaxation test,except that it shall be permissible to straighten the specimenends to fit in the testing machine jaws.6.3.3.4 Loading shall be applied at an essentially constantrate over a period of not less than 3 min and not more than 5min until the initial load is reached. Thereafter, the
26、 gage lengthshall be maintained constant. Load-relaxation readings shallcommence 1 min after the initial load has been reached.6.3.3.5 The initial load shall be 70 % of the specifedminimum breaking strength of the wire. Overstressing of thetest specimen to a level greater than 70 % of the specifiedm
27、inimum breaking strength during loading shall not be per-mitted.6.3.3.6 The test gage length shall be at least 60 times thenominal diameter of the wire.6.3.3.7 The result of each relaxation test shall be reportedeither as the actual percent of stress loss after 1000 h or theTABLE 1 Tensile Requireme
28、ntsWire Gage orFraction, in.Decimal Size,in. (mm)Class II Wire Class III WireMinimum TensileStrength,Aksi (MPa)Breaking Strength, lbf (kN) Minimum TensileStrength,Aksi (MPa)Breaking Strength, lbf (kN)min max min max6 0.192 (4.88) 222 (1530) 6 430 (28.6) 7 300 (32.5) 252 (1740) 7 300 (32.5) 8 170 (36
29、.3)1/4 0.250 (6.35) 211 (1450) 10 360 (46.1) 11 830 (52.6) 240 (1650) 11 780 (52.4) 13 250 (58.9)5/16 0.312 (7.92) 201 (1390) 15 370 (68.4) 17 660 (78.6) 221 (1520) 16 900 (75.2) 19 190 (85.4)ABased on nominal wire diameter.TABLE 2 Chemical RequirementsNOTE 1Class I wire has been discontinued.NOTE 2
30、Where “” appear in this table, there is no requirement orlimit.Classes II and IIICarbon, % 0.500.85Manganese, % 0.501.10Phosphorus, max, % 0.030Sulfur, max, % 0.035Silicon, % 0.100.35Nitrogen, max, % 0.007Aluminum, % Titanium, % Chromium, % Nickel, % Molybdenum, % Copper, % Vanadium, % A648 112extra
31、polated percent of stress loss after 1000 h as determinedfrom the linear-regression curve.NOTE 4In accordance withANSI/AWWAC 304, ordinary prestressedconcrete pipe design is based on an assumed maximum wire relaxation of7.48 % at 1000 h. Wire with higher relaxation can be used, but the higherrelaxat
32、ion loss must be known for consideration in the pipe design.6.4 Torsion Test:6.4.1 Torsion RequirementsTorsion requirements shallconform to those prescribed in Table 3 for the specified sizeand class.6.4.2 Number of TestsOne test specimen shall be takenfrom each coil.6.4.3 Test MethodConduct the tor
33、sion test in accordancewith the following:6.4.3.1 Use a twist rate of 10 to 30 r/min.6.4.3.2 Load the wire with an axial force of from 0.5 to 2 %of the minimum breaking strength of the wire.6.4.3.3 Use a test specimen length, defined as the distancebetween the testing machine jaws, of a minimum of 8
34、 in. (203mm).6.4.3.4 Use a minimum number of turns proportional to thelength of the test specimen based upon Table 3.6.4.3.5 The test shall be conducted to fracture, defined ascomplete separation of the broken ends. The test specimensshall be inspected for primary break shear area and longitudinal(s
35、piral) splitting following completion of the torsion test.(1) Primary Break ShearThe primary break face of thetest specimen shall have a clean, flush, full shear face,perpendicular to the wire axis (see Fig. 1).(2) Longitudinal (Spiral) SplittingIf the fractured speci-men shows evidence of a spiral
36、split, either visible withoutmagnification (see Fig. 2) or by an offset in the wire surfaces(see Fig. 3) detectable with a fingernail, a retest of that coilshall be conducted in accordance with 6.4.3.5 (3).(3) Retest for Splitting in Torsion The retest specimenshall have a minimum length of 8 in. (2
37、03 mm). The retest shallconsist of twisting the retest specimen proportionally to threetwists per 8 in. (203 mm) specimen length, at which point thetwisting shall be stopped and the specimen inspected while stillin the torsion machine. A spiral split in this specimen, eithervisible without magnifica
38、tion or detectable with a fingernail,shall be cause for rejection of the coil.6.4.3.6 The tested coil number, specimen length, and totalnumber of turns shall be recorded.6.5 Report of Mechanical Test Results The wire manu-facturer shall furnish a report listing the tensile, reduction-of-area, and to
39、rsion test results.7. Dimensions and Permissible Variations7.1 The diameter of the wire shall not vary from thatspecified by more than 60.002 in. (0.05 mm) in diameter normore than 0.002-in. (0.05-mm) out-of-round.8. Workmanship, Finish, and Appearance8.1 The surface of the wire as received shall be
40、 smooth andgenerally free of rust.Alight oxidation film that does not causepitting of the wire surface visible to the unaided eye afterwiping or light cleaning, shall not be cause for rejection. Coilsof wire with visible pitting shall be rejected.8.2 The wire shall not have detrimental piping, cross
41、 check-ing, torn surfaces, chatter marks, splits, die marks, scratches,pits, or seams.8.3 The wire shall not be kinked, improperly cast, or showa wavy condition.8.4 Each coil shall be one continuous length of wire,properly coiled.8.5 The wire shall not be oiled or greased.9. Inspection9.1 The manufa
42、cturer shall afford the purchasers inspectorall reasonable facilities to satisfy him that the material is beingproduced and furnished in accordance with this specification.All tests and inspections may be made at the place ofmanufacture prior to shipment and shall be so conducted as notto interfere
43、unnecessarily with the operation of the work.10. Rejection, Retesting, and Rehearing10.1 Failure of any specimen to meet the mechanicalrequirements of this specification when tested by the manufac-turer, except splitting during torsion testing, shall be causeeither for rejection of the coil represen
44、ted by the specimen orfor retesting two additional specimens from that coil. If eitheradditional specimen fails the retest for the mechanical require-ment in which the first specimen failed, the coil in questionTABLE 3 Torsion RequirementsWire Gage orFraction in.Decimal Size,in. (mm)Class II and Cla
45、ss III minturns per 8 in. (203 mm)6 0.192 (4.88) 101/4 0.250 (6.35) 85/16 0.312 (7.92) 7FIG. 1 Acceptable View of the Break FaceFIG. 2 Visible Longitudinal (Spiral) Splitting After Torsion TestingFIG. 3 End View of Offset Longitudinal (Spiral) Split After TorsionTestingA648 113shall be rejected. Req
46、uirements for retesting coils which splitduring torsion testing are described in 6.4.3.5 (3).10.2 Any rejection based on tests made in accordance withthe specification shall be reported to the wire manufacturerwithin a reasonable period of time. The material must beadequately protected and correctly
47、 identified in order that thewire manufacturer may make a proper investigation.11. Product Marking and Packaging11.1 The size of the wire, purchasers order number, ASTMspecification and class number, heat number, coil number, andname of the manufacturer shall be marked on a durable tagsecurely attac
48、hed to each coil of wire.11.2 Unless otherwise specified, packaging shall be inaccordance with the procedures in Practices A700.12. Keywords12.1 prestressed concrete pipe; prestressing; steel wireSUPPLEMENTARY REQUIREMENTSThe following supplementary requirement shall apply only when specified in the
49、 purchaser order orcontract.S1. Acceptance Criteria for Hydrogen EmbrittlementResistance TestingS1.1 Test ResultsFor a single diameter and class of wire,the results of hydrogen embrittlement tests performed inaccordance with Test Method A1032 shall be submitted to thepurchaser. No test shall result in a time-to-failure of less than75 hours. The results shall be derived from tests conductedanytime within the previous 12 months on wire of the samediameter and class and made from the same rod source as thewire being furnished. The h
