1、Designation: A881/A881M 16aStandard Specification forSteel Wire, Indented, Low-Relaxation for PrestressedConcrete1This standard is issued under the fixed designation A881/A881M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the y
2、ear 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 indented, low-relaxation steelwire for use in prestressed concrete.1.2 The values st
3、ated 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 may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining valuesfrom the two systems
4、 may result in non-conformance with thespecification.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA421/A421M Specification for Stress-Relieved Steel Wirefor Prestressed ConcreteA700 Guide for Packaging, Marking, and Loading Metho
5、dsfor Steel Products for Shipment2.2 U.S. Military Standard:3MIL-STD-129 Marking for Shipment and Storage2.3 U.S. Federal Standard:3Fed. Std. No. 123 Marking for Shipment (Civil Agencies)3. Terminology3.1 Definitions of Terms Specific to This Specification:3.1.1 indented steel wire, nindented, cold-
6、drawn, low-relaxation wire, the wire surface having indentations thatreduce longitudinal movement of the wire while also providingconsistent prestress transfer length.3.1.2 low-relaxation wire, nstraightened wire that re-ceives a suitable continuous thermo-mechanical treatment asthe last operation t
7、o produce the properties listed.4. Ordering Information4.1 Orders for indented low-relaxation steel wire for pre-stressed concrete shall include the following necessary infor-mation:4.1.1 Quantity (weight mass),4.1.2 Required minimum tensile strength (6.2),4.1.3 Nominal diameter (6.1),4.1.4 Packagin
8、g, and4.1.5 ASTM designation and year of issue.4.2 The purchaser shall have the option to specify additionalrequirements, including but not limited to, the following:4.2.1 Indentation geometry (7.2, 7.3),4.2.2 Indentation sidewall angle (7.3, 7.4),4.2.3 Welding of rod prior to cold drawing permissib
9、le(9.3),4.2.4 Outside inspection (11.1),4.2.5 Special packaging (14.1, 14.2), and4.2.6 Other special requirements, if any.5. Materials and Manufacture5.1 The steel shall be made by any commercially acceptedsteelmaking process.5.2 The base metal shall be carbon steel of such quality thatwhen drawn to
10、 wire, indented, and then thermo-mechanicallytreated, shall have the properties and characteristics prescribedin this specification.6. Mechanical Property Requirements6.1 GeneralIndented wire shall be supplied in coils,packs, or spools to the specified mechanical properties in Table1. It shall be pe
11、rmissible to furnish diameters of wire notspecifically itemized in this specification, provided that thestrength is defined and they conform otherwise to the require-ments of this specification.6.2 Tensile StrengthThe minimum tensile strength of theindented wire shall conform to the requirements of
12、Table 1.Other values of tensile strength and nominal diameters can be1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved Dec. 1, 2016. Pu
13、blished January 2017. Originallyapproved in 1990. Last previous edition approved in 2016 as A881/A881M 16.DOI: 10.1520/A0881_A0881M-16A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
14、formation, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.*A Summary of Changes section appears at the end of this standardCopyri
15、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Internation
16、al Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1specified if shown by test that the strength exceeds thatspecified. The tension test shall be made in accordance withTest Methods A370.6.3 Load at 1 % ExtensionThe load at 1 %
17、 extension shallbe at least 90 % of the minimum specified tensile strengthwhen tested in accordance with Test Methods A370.6.4 ElongationThe percent elongation after fracture on a10-in. 250-mm gage length shall be 3.0 % minimum.6.5 Bend TestA 90 degree bend test (see Fig. 1) around apin six times th
18、e nominal diameter of the wire shall beperformed once per coil/pack/spool for each row ofindentations, with the centerline of the row of indentationslocated at the outside of the bend. The wire shall be bent at auniform rate, with the duration of test to be between 10 and 30seconds. The bend locatio
19、n along the axis of the wire specimenshall be random and three locations shall be tested along thespecimen, for a total of nine bends per test. Each bend shall beinspected after testing to ensure no cracking or fracturingoccurred.6.6 RelaxationRelaxation properties shall be provided atleast annually
20、 from records of tests on finished wire.Additionalrelaxation tests shall be conducted if there is a change in rawrod supply or type. Tests to satisfy this requirement shallcomply with the conditions of Supplementary Requirement S1of Specification A421/A421M. The relaxation losses are not toexceed 3.
21、5 % after 1000 hours when tested at an initial load of80 % of minimum tensile strength.7. Requirements for Indentations7.1 IndentationsIndentations shall be in three lines spaceduniformly around the wire with one line of indentationsinclined in the opposite direction to the other two. Theindentation
22、s shall be placed in respect to the axis of the wire sothat the included angle is not less than 45, as shown in Fig. 2.Pitch and shape shall be consistent , with not more than 10 %being malformed in any 2 ft 600 mm length of wire, judgedvisually. Criteria for what constitutes a malformed indentation
23、shall be mutually agreed upon between manufacturer andpurchaser as required.TABLE 1 Tensile Strength RequirementsNominalDiameterTensileStrengthNominalAreaANominal WeightMass, lb/1000 ftg/min. mm lbf kN in.2mm20.198 5.03 7230 32.2 0.0308 19.86 104.8 155.90.198 5.03 7700 34.3 0.0308 19.86 104.8 155.90
24、.2094 5.32 9000 39.1 0.0344 22.23 117.1 174.5AThe nominal cross-sectional area is based on the nominal diameter. The actualaverage area in in.2mm2 may be calculated by dividing the weight mass perlinear in. mm of the specimen in lb kg by 0.2836 (weight of 1 in.3of steel) 7.850106kg/mm3(mass of 1 mm3
25、of steel). The amount of variation is dependent onthe shape and character of the indentations.FIG. 1 Bend Test ConfigurationA881/A881M 16a27.2 TypeTwo acceptable types of indented wire are shownin Fig. 2(a) and (b), with dimensions in Table 2.7.3 OptionsOther types of indented wire are permitted bya
26、greement, provided the wire is comparable with the acceptedtypes in mechanical properties and bond with concrete.7.4 Indentation Sidewall AngleThe manufacturer and pur-chaser shall agree upon minimum and maximum indentationsidewall angles (as shown in Fig. 2). The manufacturer shalldemonstrate proce
27、ss controls to meet mutually agreed uponrequirements.NOTE 1Shallow indentation sidewall angles can impart excessiveradial forces into the concrete. Similarly, angles that are too steep canreduce transfer length to the point of creating excessive bond demand onthe concrete. Depth of indentation, conc
28、rete properties at release ofprestress, and wire surface condition are other factors to take intoconsideration when determining min/max allowable indentation sidewallangles8. Permissible Variation in Dimensions8.1 The diameter as determined by weight mass of theindented wire shall not vary from the
29、nominal diameter bymore than 60.003 in. 60.08 mm. Diameter as determined byweight mass shall be calculated using the weight mass ofany given length of wire and densities provided in footnote ofTable 1.8.2 The indented wire shall not be out-of-round by morethan 0.003 in. 0.08 mm. Measure out-of-round
30、 using a depthgauge by placing the wire on a flat surface and checkingmaximum/minimum diameters at the same cross section.Out-of-round is the difference between maximum and mini-mum diameters measured.9. Workmanship, Finish, and Appearance9.1 The wire shall be free of kinks, tight curls, twists, ors
31、harp bends.9.2 The wire shall be furnished in firmly tied coils, packs, orspools and packaged in such a way to prevent rubbing orcollapse during shipment. Each coil, pack, or spool shall be ofone continuous length.9.3 There shall be no welds or joints in the finished wire,unless the manufacturer and
32、 purchaser mutually agree on awelding process done on wire rod prior to any cold drawingthat results in wire properties that are consistent with theintended use.Any welds or joints made after the initial drawingprocess shall be removed.9.4 Cast (Curvature)The curvature of the wire shall be 3in. 75 m
33、m maximum offset on a chord 6 ft 1.8 m long.9.5 The wire shall not be oiled or greased and must beessentially free of residual wire-drawing lubricants. Slightrusting, providing it is not sufficient to cause pits visible to aperson with normal or corrected vision, shall not be cause forrejection.10.
34、Sampling10.1 Unless otherwise agreed upon between the manufac-turer and the purchaser, test specimens shall be taken from eachcoil, pack, or spool in a lot (see Note 2) and tested to determinecompliance with 6.2 6.5 and Sections 7, 8, and 9.NOTE 2The term “lot” means all the coils, packs, or spools
35、of wire ofthe same nominal wire diameter contained in an individual shippingrelease or shipping order.FIG. 2 Acceptable Type of Indented WireTABLE 2 Dimensions of IndentationsNOTE 1Indentation sidewall angle shall be measured along the centerline axis of the wire through the center of indentation. L
36、eading and trailingsidewall angles shall be calculated using measured horizontal distances and indentation depths.NOTE 2Depth of indentation shall be the average depth of six or more random indentations measured at maximum depth.Nominal Wire Diameter, Depth, a, in. mm Nominal Length, L, Nominal Pitc
37、h, P,in. mm in. mm in. mm0.198 5.03 0.005 + 0.001, 0.0020.13 + 0.02, 0.050.1380.02 3.50.5 0.2170.02 5.50.50.2094 5.32 0.0045 0.00140.115 0.0350.1380.02 3.50.5 0.2150.011 5.460.29A881/A881M 16a311. Inspection11.1 The purchaser shall state, at the time of order, whetheroutside inspection is required.
38、If outside inspection is required,the manufacturer shall afford the inspector representing thepurchaser all reasonable facilities to satisfy him that thematerial is being furnished in accordance with this specifica-tion. All tests and inspections shall be made at the place ofmanufacture prior to shi
39、pment, unless otherwise agreed upon atthe time of purchase, and shall be so conducted withoutunnecessarily interfering with manufacturing operations.12. Rejection12.1 In case a test specimen fails to meet any requirement ofthis specification, two additional tests shall be made onspecimens of wire fr
40、om the same coil, pack, or spool and iffailure occurs in either of these tests, the coil/pack/spool shallbe rejected.12.2 Unless otherwise specified, any rejection based on testsmade in accordance with this specification shall be reported tothe manufacturer within a reasonable length of time.13. Cer
41、tification13.1 When specified in the purchase order or contract, themanufacturers certification shall be furnished to the purchaserstating that specimens representing each lot have beenmanufactured, tested, and inspected in accordance with thisspecification and the requirements have been met. The ce
42、rtifi-cation shall include the specification number, year-date ofissue, and revision letter, if any.Areport of the test results shallbe furnished.13.2 A material test report, certificate of inspection, orsimilar document printed from or used in electronic form froman electronic data interchange (EDI
43、) transmission shall beregarded as having the same validity as a counterpart 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.
44、 Notwithstanding theabsence of a signature, the organization submitting the EDItransmission is responsible for the content of the report.NOTE 3The industry definition as invoked here is: EDI is thecomputer-to-computer exchange of business information in a standardformat such as ANSI ASC X12.14. Pack
45、aging and Package Marking14.1 The nominal diameter of the indented wire, ASTMdesignation A881 A881M, and name or mark of the manu-facturer shall be marked on a tag securely attached to eachbundle of wire.14.2 When specified in the purchase order or contract, andfor direct procurement by or direct sh
46、ipment to the U.S.Government, material shall be preserved, packaged, andpacked in accordance with the requirements of Practices A700.Marking for shipment in addition to requirements specified inthe purchase order or contract, shall be in accordance withFed. Std. No. 123 for civil agencies and MIL-ST
47、D-129 formilitary agencies.15. Keywords15.1 indented wire; low-relaxation wire; prestressed con-crete; steel wire (tendon)SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this standard since the last issue(A881/A881M 16) that may impact the use of this standard. (Ap
48、proved Dec. 1, 2016.)(1) Revised Section 4.Committee A01 has identified the location of selected changes to this standard since the last issue(A881/A881M 15) that may impact the use of this standard. (Approved March 1, 2016.)(1) Revised the title, 1.1, and Section 3, and 15.1. (2) Revised throughout
49、 for editorial corrections.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and
