1、Designation: A886/A886M 10 A886/A886M 12Standard Specification forSteel Strand, Indented, Seven-Wire Stress-Relieved forPrestressed Concrete1This standard is issued under the fixed designation A886/A886M; the number immediately following the designation indicates the yearof original adoption or, in
2、the 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 seven-wire uncoated, indented, stress-relieved This speci
3、fication covers two types and two gradesof indented seven-wire uncoated, steel strand for use in pretensioned prestressed concrete construction. Grade 250I The two typesof strand are low-relaxation and stress-relieved (normal-relaxation). Grade 250I 1725I and Grade 270I 1860I have minimumultimateten
4、sile strengths of 250 ksi 1725 MPa and 270 ksi 1860 MPa, respectively, based on the nominal area of the strand.1.2 Supplement I describes low-relaxation strand and relaxation testing for that product. Low-relaxation strand shall befurnished when specifically ordered and furnished in place of stress-
5、relieved strand if mutually agreed to by the purchaser andsupplier.1.2 This specification is applicable for orders in either inch-pound units (as Specification A886) or in SI units (as SpecificationA886M).1.3 The values stated in either inch-pound units or SI units are to be regarded separately as s
6、tandards.standard. Within the text,the inch-poundSI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each systemmustshall be used independently of the other. Combining values from the two systems may result in nonconformancenon-conformance with the
7、specification.2. Referenced Documents2.1 ASTM Standards:Standard:2A1061/A1061M Test Methods for Testing Multi-Wire Steel Strand2.2 U.S. Military Standards:Standard:MIL-STD-129 Marking for Shipment and Storage3MIL-STD-163 Steel Mill Products Preparation for Shipment and Storage32.3 U.S. Federal Stand
8、ards:Standard:Fed. Std. No. 123 Marking for Shipments (Civil Agencies)33. Terminology3.1 DefinitionsDefinition of TermsTerm Specific to This Standard:this Specification:3.1.1 strand, nall strand shall be of the seven-wire type a group of wires having a center wire enclosed tightly by six helicallypl
9、aced outer wires with uniform pitch of not less than 12 and not more than 16 times the nominal diameter of the strand.3.1.1.1 DiscussionThe direction of lay may be either right- or left-hand; however, strands of different lays should not be spliced together.1 This specification is under the jurisdic
10、tion of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.05on Steel Reinforcement.Current edition approved April 1, 2010Nov. 15, 2012. Published July 2010December 2012. Originally approved in 1988. Last previous edition approved in
11、20052010 asA886/A886M 05.A886/A886M 10. DOI: 10.1520/A0886_A0886M-10.10.1520/A0886_A0886M-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Documen
12、t Summary page on the ASTM website.3 Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard a
13、n 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 published by ASTM is t
14、o 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. Ordering Information4.1 It shall be the responsibility of the purchaser to speci
15、fy all requirements that are necessary for material ordered tounder thisspecification. Such requirements shall to be considered include, but are not limited to, the following:4.1.1 Quantity (metres feet),(feet metres),4.1.2 Diameter Nominal diameter of strand (millimetres inches),(inches millimetres
16、),4.1.3 Grade of strand,4.1.4 Packaging,Type of strand (low-relaxation or stress-relieved (normal-relaxation),4.1.5 Other types of indented wire (7.4.2),4.1.6 If joints or splices are permitted (8.1.1),4.1.7 Weldless, if desired (8.1.4),4.1.8 Inspection (11.1),4.1.9 Load-elongation curve, if desired
17、 (13.2),4.1.10 Packaging (4.1), and4.1.11 ASTM designation and year of issue, andissue.4.1.6 Special requirements, if any.NOTE 1A typical ordering description is as follows: 25 600 m (84 000 ft) 12.70-mm (0.5-in.), Grade 1860I (2701) strand, in 3658-m (12 000-ft)spoolless packs to ASTM A886/A886M_.5
18、. Materials and Manufacture5.1 Base MetalThe base metal shall be carbon steel of such quality that when it is drawn to wire, subjected to the indentationprocess, fabricated into strand, and then stress-relieved, thermally treated, it shall have the properties and characteristics prescribedin this sp
19、ecification.5.2 WireThe wire from which the strand is to be fabricated shall have a common dry-drawn finish.NOTE 1This product is a composite of seven wires and is produced to mechanical properties only, the only the prescribed mechanical properties. Thechemical composition of all wires or any indiv
20、idual wire is not pertinent to this application, and heat identity is not necessarily maintained. It is possiblethat wire from more than one heat may be used in the manufacture of a reel or reelless pack. Traceability is based on pack identity the identity of reelsor reelless packs as maintained and
21、 reported by the manufacturer.5.3 IndentationsThe outer wires shall have indentations designed to reduce that inhibit longitudinal movement of the strandwithin the concrete, and relative to the concrete surrounding the strand in prestressed concrete construction. Indentations shallconform to the pro
22、visions in Section 77.4. The surface of the outer wires shall be suitably deformed mechanically by rolling toproduce a series of indentations. Indentations shall be in two or more lines spaced uniformly around the wire. Indentations inadjacent lines shall be staggered throughout the length of the wi
23、re. At least 90 % of the indentations in any 0.6 m (2 ft)2 ft 0.6m length of strand shall meet the pitch and shape requirements of Table 1. The center wire need not be indented.5.4 Stress-RelievingTreatmentAfter stranding, alllow-relaxation strand shall be subjected to a stress-relieving continuoush
24、eatthermal-mechanical treatment to produce the prescribed mechanical properties. For stress-relieved (normal-relaxation) strand,only thermal treatment is necessary. Temper colors which result from the stress-relieving operation are considered normal for thefinished appearance of this strand.TABLE 1
25、Nominal Dimensions of IndentationsFig.Wire Diameter, d StrandDiameterDepth, a Length, L Pitch, Pmmin.mm in. mm in. mm in. mm in.1 (a) 2.6 and below 0.104 andbelow7.9 0.312 0.05 to 0.10 0.002 to0.0042.0 0.079 5.6 0.2201 (a) over 3.2 over 0.125 9.5 0.375 0.05 to 0.13 0.002 to0.005 2.7 0.108 5.6 0.2201
26、1.1 0.43812.7 0.5001 (b) 3.2 and below 0.125 andbelow9.5 0.375 0.05 to 0.15 0.002 to0.0062.9 0.115 5.6 0.220TABLE 1 Nominal Dimensions of IndentationsFig.Wire Diameter, d Nominal Diameterof StrandDepth, a Length, L Pitch, Pin. mm in. mm in. mm in. mm in. mm1 (a) # 0.104 # 2.6 0.312 7.9 0.002 to 0.00
27、4 0.05 to 0.10 0.079 2.0 0.220 5.61 (a) 0.125 3.2 0.375 9.5 0.002 to 0.005 0.05 to 0.13 0.108 2.7 0.220 5.60.438 11.10.500 12.71 (b) # 0.125 # 3.2 0.375 9.5 0.002 to 0.006 0.05 to 0.15 0.115 2.9 0.220 5.6A886/A886M 1226. Mechanical Property Requirements6.1 Tests for mechanical properties shall be co
28、nducted 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 2.6.3 Yield StrengthYield strength in kN (lb)lbs kN shall be measured at 1 % extension under load. The load at this extensionsh
29、all be recorded as the yield strength minimum yield strength shall be 90 % for low-relaxation strand and 85 % for stress-relieved(normal-relaxation) strand of the breaking strength listed in Table 2and shall meet the requirements prescribed. Initial loads for thetest and minimum yield strengths are
30、listed in Table 3.6.3.1 The extension under load shall be measured by an extensometer calibrated with the smallest division not larger than0.0001 mm/mm (0.001 in./in.)in./in. 0.0001 mm/mm of gage length.6.4 ElongationThe total elongation under load shall not be less than 3.5 % using a gage length of
31、 not less than 600 mm (24in.).24 in. 600 mm. It shall be permissible to determine the total elongation value by adding to the 1 % yield extension the percentextension or movement between the jaws gripping the strand after yield determination. The percent is calculated on the new baselength of jaw-to
32、-jaw distance.6.5 Relaxation PropertiesLow-relaxation strand shall have relaxation losses of not more than 2.5 % when initially loaded to70 % of specified minimum breaking strength or not more than 3.5 % when loaded to 80 % of specified minimum breaking strengthof the strand after 1000 hours of test
33、ing.6.5.1 If required, relaxation evidence shall be provided from the manufacturers records of tests on similarly dimensioned strandof the same grade.TABLE 2 Breaking Strength RequirementsDiameter of StrandBreaking Strengthof Strand, kN lbfSteelArea of Strand,mm2 in.2Mass Weight ofStrand,kg/1000 mlb
34、/1000 ftmm in.Grade 1725I 250I6.4 0.250 40.0 9 000 23.2 0.036 182 1227.9 0.313 64.5 1450037.4 0.058 294 1979.5 0.375 89.0 2000051.6 0.080 405 27211.1 0.438 120.1 2700069.7 0.108 548 36712.7 0.500 160.1 3600092.9 0.144 730 49015.2 0.600 240.2 54000139.4 0.216 1094 737Grade 1860I 270I7.9 0.313 74.3 16
35、50039.4 0.061 313 2109.5 0.375 102.3 2300054.8 0.085 432 29011.1 0.438 137.9 3100074.2 0.115 582 39012.7 0.500 183.7 4130098.7 0.153 775 52015.2 0.600 266.7 58600140.0 0.217 1102 740TABLE 2 Breaking Strength RequirementsNomminalDiameter of Strand Breaking Strengthof Strand, lbf kNSteelArea of Strand
36、,in.2 mm2Mass Weight ofStrand,lb/1000 ftkg/1000 min. mmGrade 250I 1725I0.250 6.4 9 000 40.0 0.036 23.2 122 1820.313 7.9 14 500 64.5 0.058 37.4 197 2940.375 9.5 20 000 89.0 0.080 51.6 272 4050.438 11.1 27 000 120.1 0.108 69.7 367 5480.500 12.7 36 000 160.3 0.144 92.9 490 7300.600 15.2 54 000 240.5 0.
37、216 139.4 737 1094Grade 270I 1860I0.313 7.9 16 500 74.3 0.061 39.4 210 3130.375 9.5 23 000 101.9 0.085 54.8 290 4320.438 11.1 31 000 138.0 0.115 74.2 390 5820.500 12.7 41 300 183.6 0.153 98.7 520 7750.600 15.2 58 600 260.4 0.217 140.0 740 1102A886/A886M 1237. Dimensions and Permissible Variations7.1
38、 The size of the finished strand shall be expressed as the nominal diameter of the strand in decimals of an inch millimetre.inches mm. All nominal dimensional requirements for wires and strands shall refer to the wire and strand before indenting.7.2 The diameter of the center wire of any strand must
39、shall be larger than the diameter of any outer wire in accordance withTable 4.7.3 Permissible Variations in Diameter:7.3.1 All Grade 250I 1725I strand shall conform to a size tolerance of 60.40 mm (60.016 in.)60.016 in. 60.40 mm fromthe nominal diameter measured across the crowns of the wire.7.3.2 A
40、ll Grade 270I 1860I strand shall conform to a size tolerance of +0.65 mm, 0.15 mm (+0.026 in., 0.006 in.)+0.026in., 0.006 in. +0.65 mm, 0.15 mm from the nominal diameter measured across the crowns of the wire.7.3.3 Variation in cross-sectional area and in stress resulting therefrom shall not be caus
41、e for rejection provided the diameterdifferences of the individual wires and the diameters of the strand are within the tolerances specified.7.4 Indentations:7.4.1 Two acceptable types of indented wire are shown in Fig. 1 (a) and (b) with dimensions given in Table 1.7.4.2 Other types of indented wir
42、e are permitted, by agreement between the purchaser and supplier.manufacturer.8. Workmanship, Finish, and Appearance8.1 Joints:8.1.1 There shall be no strand joints or strand splices in any length of the completed strand unless specifically permitted by thepurchaser.8.1.2 During the process of manuf
43、acture of the individual wires for stranding, welding is permitted only prior to or at the sizeof the last thermal treatment, for example, patenting or control cooling. There shall be no welds in the wire after it has been drawnthrough the first die in the wire drawing except as provided in 8.1.3.TA
44、BLE 3 Yield Strength RequirementsADiameter ofStrandInitial Load,kN lbfMinimum Load at 1 % Extension,kN lbfmm in.Grade 1725I 250I6.4 0.250 4.0 900 34.0 7 6507.9 0.313 6.5 1 450 54.7 12 3009.5 0.375 8.9 2 000 75.6 17 00011.1 0.438 12.0 2 700 102.3 23 00012.7 0.500 16.0 3 600 136.2 30 60015.2 0.600 24.
45、0 5 400 204.2 45 900Grade 1860I 270I7.9 0.313 7.3 1 650 62.4 14 0309.5 0.375 10.2 2 300 87.0 19 55011.1 0.438 13.8 3 100 117.2 26 35012.7 0.500 18.4 4 130 156.1 35 00015.2 0.600 26.1 5 860 221.5 49 800TABLE 3 Yield Strength RequirementsANominalDiameter ofStrandInitial Load,lbf kNMinimum Load at 1 %
46、Extension,kN lbfin. mm Stress-Relieved(NormalRelaxation)ALowRelaxationBGrade 1725I 250I0.250 6.4 900 4.0 7 650 34.0 8 100 36.00.313 7.9 1 450 6.5 12 300 54.8 13 050 58.10.375 9.5 2 000 8.9 17 000 75.6 18 000 80.10.438 11.1 2 700 12.0 23 000 102.3 24 300 108.20.500 12.7 3 600 16.0 30 600 136.2 32 400
47、 144.30.600 15.2 5 400 24.0 45 900 204.4 48 600 216.5Grade 1860I 270I0.313 7.9 1 650 7.3 14 030 63.2 14 850 66.90.375 9.5 2 300 10.2 19 550 86.6 20 700 91.70.438 11.1 3 100 13.8 26 350 117.3 27 900 124.20.500 12.7 4 130 18.4 35 000 156.1 37 170 165.20.600 15.2 5 860 26.1 49 800 221.3 52 740 234.4AYi
48、eld strength minimum Minimum yield strength is 85 % of specified minimumbreaking strength.B Minimum yield strength is 90 % of specified minimum breaking strength.A886/A886M 1248.1.3 During fabrication of the strand, butt-welded joints are permitted in the individual wires, provided there is not more thanone such joint in any 45-m (150-ft)150-ft 45-m section
