1、Designation: A881/A881M 15A881/A881M 16Standard Specification forSteel Wire, Indented, Low-Relaxation for PrestressedConcrete Railroad Ties1This standard is issued under the fixed designation A881/A881M; the number immediately following the designation indicates the yearof original adoption or, in t
2、he case of 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.1. Scope*1.1 This specification covers uncoated, indented, low-relaxation steel wire for use as p
3、restressing tendons in concrete railroadties.in prestressed concrete.1.2 The values stated 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, e
4、ach system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with the standard.specification.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA421/A421M Specification for St
5、ress-Relieved Steel Wire for Prestressed ConcreteA700 Guide for Packaging, Marking, and Loading Methods for Steel Products for ShipmentE328 Test Methods for Stress Relaxation for Materials and Structures2.2 U.S. Military Standards:Standard:3MIL-STD-129 Marking for Shipment and Storage2.3 U.S. Federa
6、l Standard:3Fed. Std. No. 123 Marking for Shipment (Civil Agencies)3. Terminology3.1 Definitions of Terms Specific to This Standard:Specification:3.1.1 indented steel wire for railroad ties, wire, nindented, cold-drawn, uncoated, low-relaxation wire intended for use asprestressing tendons in concret
7、e railroad ties, low-relaxation wire, the wire surface having indentations that reduce longitudinalmovement of the wire while also providing consistent prestress transfer length.3.1.2 low-relaxation wire, nindented cold-drawn wire, straightened, straightened wire that receives a suitable continuoust
8、hermo-mechanical treatment as the last operation to produce the properties listed.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specify all requirements that are necessary for material ordered to thisspecification. Such requirements shall include, but are not limited
9、to, the following:4.1.1 Quantity (weight mass),4.1.2 Name of material (indented, low-relaxation steel wire for prestressed concrete railroad ties),concrete),4.1.3 Required minimum tensile strength (see Table 1),4.1.4 Nominal diameter,4.1.5 Packaging,4.1.6 ASTM designation and year of issue, and1 Thi
10、s specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.05on Steel Reinforcement.Current edition approved Nov. 1, 2015March 1, 2016. Published December 2015March 2016. Originally approved in 1990.
11、 Last previous edition approved in 20102015as A881/A881M 10.A881/A881M 15. DOI: 10.1520/A0881_A0881M-15.10.1520/A0881_A0881M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information
12、, refer to the standards Document Summary page on the ASTM website.3 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.This document is not an ASTM standard and is intended only to provide the use
13、r of an ASTM standard an indication of 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
14、 published by ASTM is to be considered 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 States14.1.7 Special requirements (such as, indentation sidewall an
15、gle or outside inspection), if any.5. Materials and Manufacture5.1 The steel shall be made by any commercially accepted process.5.2 The base metal shall be carbon steel of such quality that when drawn to wire, indented, and then thermo-mechanicallytreated, shall have the properties and characteristi
16、cs prescribed in this specification.6. Mechanical Property Requirements6.1 GeneralIndented wire shall be supplied in coils, packs, or spools to the specified mechanical properties in Table 1. It shallbe permissible to furnish diameters of wire not specifically itemized in this specification, provide
17、d that the strength is defined andthey conform otherwise to the requirements of this specification.6.2 Tensile StrengthThe minimum tensile strength of the indented wire shall conform to the requirements of Table 1. Othervalues of tensile strength and nominal diameters can be specified if shown by te
18、st that the strength exceeds that specified. Thetension test shall be made in accordance with Test Methods A370.6.3 Load at 1 % ExtensionThe load at 1 % extension shall be at least 90 % of the minimum specified tensile strength whentested in accordance with Test Methods A370.6.4 ElongationThe percen
19、t elongation after fracture on a 10-in. 250-mm gage length shall be 3.0 % minimum.6.5 Bend TestA 90 degree bend test (see Fig. 1) around a pin six times the nominal diameter of the wire shall be performedonce per pack/coilcoil/pack/spool for each row of indentations, with the centerline of the row o
20、f indentations located at the outsideof the bend. The wire shall be bent at a uniform rate, with the duration of test to be between 10 and 30 seconds. The bend locationalong the axis of the wire specimen shall be random and three locations shall be tested along the specimen, for a total of nine bend
21、sper test. Each bend shall be inspected after testing to ensure no cracking or breakingfracturing occurred.6.6 RelaxationRelaxation properties shall be provided at least annually from records of tests on finished wire. Additionalrelaxation tests shall be conducted if there is a change in raw rod sup
22、ply or type. Tests to satisfy this requirement shall complywith the conditions of Supplementary Requirement S6S1 of Specification A421/A421M. The relaxation losses are not to exceed3.5 % after 1000 hours when tested at an initial load of 80 % of minimum tensile strength.7. Requirements for Indentati
23、ons7.1 IndentationsIndentations shall be in three lines spaced uniformly around the wire with one line of indentations inclinedin the opposite direction to the other two. The indentations shall be placed in respect to the axis of the wire so that the includedangle is not less than 45, as shown in Fi
24、g. 2. Pitch and shape shall be consistent , with not more than 10 % being malformed inany 2 ft 600 mm length of wire, judged visually. Criteria for what constitutes a malformed indentation shall be mutually agreedupon between manufacturer and purchaser as required.7.2 TypeTwo acceptable types of ind
25、ented wire are shown in Fig. 2(a) and (b), with dimensions in Table 2.7.3 OptionsOther types of indented wire are permitted by agreement, provided the wire is comparable with the accepted typesin mechanical properties and bond with concrete.7.4 Indentation Sidewall AngleThe manufacturer and purchase
26、r shall agree upon minimum and maximum indentationsidewall angles (as shown in Fig. 2). The manufacturer shall demonstrate process controls to meet mutually agreed uponrequirements.NOTE 1Shallow indentation sidewall angles can impart excessive radial forces into the concrete. Similarly, angles that
27、are too steep can reducetransfer length to the point of creating excessive bond demand on the concrete. Depth of indentation, concrete properties at release of prestress, and wiresurface condition are other factors to take into consideration when determining min/max allowable indentation sidewall an
28、glesTABLE 1 Tensile Strength RequirementsNominalDiameterTensileStrengthNominalAreaANominal WeightMass, lb/1000 ftg/min. mm lbf kN in.2 mm20.198 5.03 7230 32.2 0.0308 19.86 104.8 155.90.198 5.03 7700 34.3 0.0308 19.86 104.8 155.90.2094 5.32 9000 39.1 0.0344 22.23 117.1 174.5A The nominal cross-sectio
29、nal area is based on the nominal diameter. The actualaverage area in in.2 mm2 may be calculated by dividing the mass (weight)weightmass per linear in. mm of the specimen in lb kg by 0.2836 (weight of 1 in.3 ofsteel) 7.850 106 kg/mm3 (mass of 1 mm3 of steel). The amount of variation isdependent on th
30、e shape and character of the indentations.A881/A881M 1628. Permissible Variation in Dimensions8.1 The diameter as determined by weight mass of the indented wire shall not vary from the nominal diameter by more than60.003 in. 60.08 mm. Diameter as determined by weight mass shall be calculated using t
31、he weight mass of any given lengthof wire and densities provided in footnote of Table 1.8.2 The indented wire shall not be out-of-round by more than 0.003 in. 0.08 mm. (Measured Measure out-of-round using adepth gauge by placing the wire on a flat surface and checking maximum/minimum diameters at th
32、e same cross section.Out-of-round is the difference between maximum and minimum diameters measured.) measured.9. Workmanship, Finish, and Appearance9.1 The wire shall be free of kinks.FIG. 1 Bend Test ConfigurationFIG. 2 Acceptable Type of Indented WireA881/A881M 1639.2 The wire shall be furnished i
33、n firmly tied coils, packs, or spools and packaged in such a way to prevent rubbing or collapseduring shipment. Each coil, pack, or spool shall be of one continuous length.9.3 There shall be no welds or joints in the finished wire, unless the manufacturer and purchaser mutually agree on a weldingpro
34、cess done on wire rod prior to any cold drawing that results in wire properties that are consistent with the intended use. Anywelds or joints made after the initial drawing process shall be removed.9.4 Cast (Curvature)The curvature of the wire shall be 3 in. 75 mm maximum offset on a chord 6 ft 1.8
35、m long.9.5 The wire shall not be oiled or greased and must be essentially free of residual wire-drawing lubricants. Slight rusting,providing it is not sufficient to cause pits visible to a person with normal or corrected vision, shall not be cause for rejection.10. Sampling10.1 Unless otherwise agre
36、ed upon between the manufacturer and the purchaser, test specimens shall be taken from each coil,pack, or spool in a lot (see Note 2) and tested to determine compliance with 6.2 6.5 and Sections 7, 8, and 9.NOTE 2The term “lot” means all the coils, packs, or spools of wire of the same nominal wire d
37、iameter contained in an individual shipping releaseor shipping order.11. Inspection11.1 The purchaser shall state, at the time of order, whether outside inspection is required. If outside inspection is required, themanufacturer shall afford the inspector representing the purchaser all reasonable fac
38、ilities to satisfy him that the material is beingfurnished in accordance with this specification. All tests and inspections shall be made at the place of manufacture prior toshipment, unless otherwise agreed upon at the time of purchase, and shall be so conducted without unnecessarily interfering wi
39、thmanufacturing operations.12. Rejection12.1 In case a test specimen fails to meet any requirement of this specification, two additional tests shall be made onsamplesspecimens of wire from the same coil, pack, or spool and if failure occurs in either of these tests, the coil/pack/spool shallbe rejec
40、ted.12.2 Unless otherwise specified, any rejection based on tests made in accordance with this specification shall be reported to themanufacturer within a reasonable length of time.13. Certification13.1 When specified in the purchase order or contract, the manufacturers certification shall be furnis
41、hed to the purchaser statingthat samplesspecimens representing each lot have been manufactured, tested, and inspected in accordance with this specificationand the requirements have been met. The certification shall include the specification number, year-date of issue, and revision letter,if any. A r
42、eport of the test results shall be furnished.13.2 A material test report, certificate of inspection, or similar document printed from or used in electronic form from anelectronic data interchange (EDI) transmission shall be regarded as having the same validity as a counterpart printed in thecertifie
43、rs facility. The content of the EDI transmitted document mustshall meet the requirements of the invokedASTM standard(s)and conform to any existing EDI agreement between the purchaser and the supplier.manufacturer. Notwithstanding the absence ofa signature, the organization submitting the EDI transmi
44、ssion is responsible for the content of the report.NOTE 3The industry definition as invoked here is: EDI is the computer-to-computer exchange of business information in a standard format such asANSI ASC X12.14. Packaging and Package Marking14.1 The nominal diameter of the indented wire, ASTM specifi
45、cation designation,designation A881 A881M, and name ormark of the manufacturer shall be marked on a tag securely attached to each bundle of wire.TABLE 2 Dimensions of IndentationsNOTE 1Indentation sidewall angle shall be measured along the centerline axis of the wire through the center of indentatio
46、n. Leading 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
47、Pitch, P,in. mm in. mm in. mm0.198 5.03 0.005 + 0.001, 0.0020.13 + 0.02, 0.050.138 0.02 3.5 0.5 0.217 0.02 5.5 0.50.2094 5.32 0.0045 0.00140.115 0.0350.138 0.02 3.5 0.5 0.215 0.011 5.46 0.29A881/A881M 16414.2 For Government Procurement OnlyWhen specified in the contract purchase order or order,contr
48、act, and for directprocurement by or direct shipment to the U.S. Government, material shall be preserved, packaged, and packed in accordance withthe requirements of Practices A700. Marking for shipment in addition to requirements specified in the contract purchase order ororder,contract, shall be in
49、 accordance with Fed. Std. No. 123 for civil agencies and MIL-STD-129 for military agencies.15. Keywords15.1 concrete railroad ties; indented wire; indentedlow-relaxation wire; prestressed concrete; steel wire (tendon)SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this standard since the last issue(A881/A881M 10A881/A881M 15) that may impact the use of this standard. (Approved Nov. 1,2011.)March 1
