1、Designation: A 886/A 886M 05Standard Specification forSteel Strand, Indented, Seven-Wire Stress-Relieved forPrestressed Concrete1This standard is issued under the fixed designationA886/A886M; the number immediately following the designation indicates the yearof original adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers seven-wire uncoated, indented,stress-relieved steel strand for use in
3、 pretensioned prestressedconcrete construction. Grade 250I and Grade 270I have mini-mum ultimate strengths of 250 ksi 1725 MPa and 270 ksi1860 MPa, respectively, based on the nominal area of thestrand.1.2 Supplement I describes low-relaxation strand and relax-ation testing for that product. Low-rela
4、xation strand shall befurnished when specifically ordered and furnished in place ofstress-relieved strand if mutually agreed to by the purchaserand supplier.1.3 This specification is applicable for orders in eitherinch-pound units (as Specification A 886) or in SI units (asSpecification A 886M).1.4
5、The values stated in either inch-pound units or SI unitsare to be regarded separately as standards. Within the text, theinch-pound units are shown in brackets. The values stated ineach system are not exact equivalents; therefore, each systemmust be used independently of the other. Combining valuesfr
6、om the two systems may result in nonconformance with thespecification.2. Referenced Documents2.1 ASTM Standards:2A 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsE 328 Methods for Stress RelaxationTests for Materials andStructures2.2 U.S. Military Standards:MIL-STD-129 Marki
7、ng for Shipment and Storage3MIL-STD-163 Steel Mill Products Preparation for Ship-ment and Storage32.3 U.S. Federal Standards:Fed. Std. No. 123 Marking for Shipments (Civil Agencies)33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 strand, nall strand shall be of the seven-wire
8、typehaving a center wire enclosed tightly by six helically placedouter wires with uniform pitch of not less than 12 and not morethan 16 times the nominal diameter of the strand.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specifyall requirements that are necessary fo
9、r material ordered to thisspecification. Such requirements shall include, but are notlimited to, the following:4.1.1 Quantity (meters feet),4.1.2 Diameter of strand (millimeters inches),4.1.3 Grade of strand,4.1.4 Packaging,4.1.5 ASTM designation and year of issue, and4.1.6 Special requirements, if
10、any.NOTE 1Atypical ordering description is as follows: 25 600 m (84 000ft) 12.70-mm (0.5-in.), Grade 1860I (2701) strand, in 3658-m (12 000-ft)spoolless packs to ASTM A 886/A 886M_.5. Materials and Manufacture5.1 Base MetalThe base metal shall be carbon steel ofsuch quality that when it is drawn to
11、wire, subjected to theindentation process, fabricated into strand, and then stress-relieved, it shall have the properties and characteristics pre-scribed in this specification.5.2 WireThe wire from which the strand is to be fabri-cated shall have a common dry-drawn finish.NOTE 2This product is a com
12、posite of seven wires and is produced tomechanical properties only, the chemical composition of all wires or anyindividual wire is not pertinent to this application, and heat identity is notnecessarily maintained. It is possible that wire from more than one heatmay be used in the manufacture of a re
13、el or pack. Traceability is based onpack identity as maintained and reported by the manufacturer.1This 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 edit
14、ion approved Sept. 1, 2005. Published October 2005. Originallyapproved in 1988. Last previous edition approved in 2002 as A 886/A 886M 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
15、information, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Internatio
16、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 IndentationsThe outer wires shall have indentationsdesigned to reduce longitudinal movement of the strand withinthe concrete, and conform to the provisions in Section7. Thesurface of the outer wires shall be
17、 suitably deformed mechani-cally by rolling to produce a series of indentations. Indenta-tions shall be in two or more lines spaced uniformly around thewire. Indentations in adjacent lines shall be staggered through-out the length of the wire. At least 90 % of the indentations inany 0.6 m (2 ft) len
18、gth of strand shall meet the pitch and shaperequirements of Table 1. The center wire need not be indented.5.4 Stress-RelievingAfter stranding, all strand shall besubjected to a stress-relieving continuous heat treatment toproduce the prescribed mechanical properties. Temper colorswhich result from t
19、he stress-relieving operation are considerednormal for the finished appearance of this strand.6. Mechanical Property Requirements6.1 Methods of testing for mechanical properties are de-scribed in Supplement VII of Methods and Definitions A 370.6.2 Breaking StrengthThe breaking strength of the fin-is
20、hed strand shall conform to the requirements prescribed inTable 2.6.3 Yield StrengthYield strength in kN (lb) shall bemeasured at 1 % extension under load. The load at thisextension shall be recorded as the yield strength and shall meetthe requirements prescribed in Table 3.6.3.1 The extension under
21、 load shall be measured by anextensometer calibrated with the smallest division not largerthan 0.0001 mm/mm (0.001 in./in.) of gage length.6.4 ElongationThe total elongation under load shall notbe less than 3.5 % using a gage length of not less than 600 mm(24 in.). It shall be permissible to determi
22、ne the total elongationvalue by adding to the 1 % yield extension the percentextension or movement between the jaws gripping the strandafter yield determination. The percent is calculated on the newbase length of jaw-to-jaw distance.7. Dimensions and Permissible Variations7.1 The size of the finishe
23、d strand shall be expressed as thediameter of the strand in decimals of an inch millimetre. Allnominal dimensional requirements for wires and strands shallrefer to the wire and strand before indenting.7.2 The diameter of the center wire of any strand must belarger than the diameter of any outer wire
24、 in accordance withTable 4.7.3 Permissible Variations in Diameter:7.3.1 All Grade 250I strand shall conform to a size toleranceof 60.40 mm (60.016 in.) from the nominal diameter mea-sured across the crowns of the wire.7.3.2 All Grade 270I strand shall conform to a size toleranceof +0.65 mm, 0.15 mm
25、(+0.026 in., 0.006 in.) from thenominal diameter measured across the crowns of the wire.7.3.3 Variation in cross-sectional area and in stress resultingtherefrom shall not be cause for rejection provided the diameterdifferences of the individual wires and the diameters of thestrand are within the tol
26、erances specified.7.4 Indentations:7.4.1 Two acceptable types of indented wire are shown inFig. 1 (a) and ( b) with dimensions given in Table 1.7.4.2 Other types of indented wire are permitted, by agree-ment between the purchaser and supplier.8. Workmanship, Finish, and Appearance8.1 Joints:TABLE 1
27、Nominal Dimensions of IndentationsFig.Wire Diameter, d Strand Diameter Depth, a Length, L Pitch, Pmm in. mm in. mm in. mm in. mm in.1(a) 2.6 and below 0.104 and below 7.9 0.312 0.05 to 0.10 0.002 to 0.004 2.0 0.079 5.6 0.2201(a) over 3.2 over 0.125 9.5 0.375 0.05 to 0.13 0.002 to 0.005 2.7 0.108 5.6
28、 0.22011.1 0.43812.7 0.5001(b) 3.2 and below 0.125 and below 9.5 0.375 0.05 to 0.15 0.002 to 0.006 2.9 0.115 5.6 0.220TABLE 2 Breaking Strength RequirementsDiameter of StrandBreaking Strengthof Strand, kN lbfSteelArea of Strand,mm2in.2Mass Weightof Strand,kg/1000 mlb/1000 ftmm in.Grade 1725I 250I6.4
29、 0.250 40.0 9 000 23.2 0.036 182 1227.9 0.313 64.5 14 500 37.4 0.058 294 1979.5 0.375 89.0 20 000 51.6 0.080 405 27211.1 0.438 120.1 27 000 69.7 0.108 548 36712.7 0.500 160.1 36 000 92.9 0.144 730 49015.2 0.600 240.2 54 000 139.4 0.216 1094 737Grade 1860I 270I7.9 0.313 74.3 16 500 39.4 0.061 313 210
30、9.5 0.375 102.3 23 000 54.8 0.085 432 29011.1 0.438 137.9 31 000 74.2 0.115 582 39012.7 0.500 183.7 41 300 98.7 0.153 775 52015.2 0.600 266.7 58 600 140.0 0.217 1102 740TABLE 3 Yield Strength RequirementsADiameter of StrandInitial Load,kN lbfMinimum Load at1 % Extension, kNlbfmm in.Grade 1725I250I6.
31、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 24.0 5 400 204.2 45 900Grade 1860I270I7.9 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 3
32、5012.7 0.500 18.4 4 130 156.1 35 00015.2 0.600 26.1 5 860 221.5 49 800AYield strength minimum is 85 % of specified minimum breaking strength.A 886/A 886M 0528.1.1 There shall be no strand joints or strand splices in anylength of the completed strand unless specifically permitted bythe purchaser.8.1.
33、2 During the process of manufacture of the individualwires for stranding, welding is permitted only prior to or at thesize of the last thermal treatment, for example, patenting orcontrol cooling. There shall be no welds in the wire after it hasbeen drawn through the first die in the wire drawing exc
34、ept asprovided in 8.1.3.8.1.3 During fabrication of the strand, butt-welded joints arepermitted in the individual wires, provided there is not morethan one such joint in any 45-m (150-ft) section of thecompleted strand.NOTE 3When specifically ordered as “weldless grade,” a product freeof welds shall
35、 be furnished. When this grade is specified, no welds orjoints are permitted except as detailed in 8.1.2.8.2 The finished strand shall be uniform in diameter andshall be free of imperfections not consistent with good com-mercial stranding practice.8.3 When strand is cut without seizing, if no wire f
36、lies outof position, or if any wire that flies out of position can berepositioned by hand, the strand shall be considered satisfac-tory.8.4 The strand shall not be oiled or greased. Slight rusting,provided it is not sufficient to cause pits visible to the unaidedeye, shall not be cause for rejection
37、.9. Sampling9.1 Test specimens cut from either end of the strand packageof reels or either end of coils or reelless packs are permitted.Discard any specimen found to contain a wire joint and obtaina new specimen.10. Number of Tests10.1 One specimen for test shall be taken from each 18 Mg(20-ton) pro
38、duction lot of finished strand and tested for tensilestrength, yield strength, and elongation.11. Inspection11.1 The purchaser may request that a representative inspector witness the inspection and testing of the material prior toshipment. Such agreement shall be made by the purchaser andproducer as
39、 part of the purchase contract.11.2 When such inspection or witness of inspection andtesting is agreed upon, the purchasers representative shall beafforded all reasonable facilities to assure that the materialmeets the requirements of this specification. Inspection andtests shall be conducted so as
40、to avoid unnecessary interferencewith the producers operations.12. Rejection12.1 Failure of any test specimen to comply with therequirements of this specification shall constitute grounds forrejection of the lot represented by the specimen.12.2 The lot may be resubmitted for inspection by testing as
41、ample from each reel or pack and sorting out nonconformingmaterial.12.3 In the event that testing of any individual sampleresults in a reasonable doubt as to the ability of the strand tosatisfy any requirement of this specification, two additionaltests shall be made on samples of strand from the sam
42、e reel orpack, and if failure occurs in either of these tests, therepresented reel or pack shall be rejected.13. Certification13.1 In the event that outside inspection is waived, amanufacturers certification that the material has been tested inaccordance with and meets the requirements of this speci
43、fica-tion shall be the basis of acceptance of the material.13.2 The manufacturer shall, when requested in the order,furnish a representative load-elongation curve for each size andgrade of strand shipped.13.3 When the modulus of elasticity of a seven-wire strandis provided, the cross-sectional area
44、used to compute thatmodulus shall also be provided. The area provided in thecertification shall be the area used to calculate the modulus ofelasticity.13.4 A material test report, certificate of inspection, orsimilar document printed from or used in electronic form froman electronic data interchange
45、 (EDI) transmission shall beregarded as having the same validity as a counterpart printed inthe certifiers facility. The content of the EDI transmittedTABLE 4 Diameter Relation Between Center and Outer WiresNominal Diameter of StrandMinimum Difference Between CenterWire Diameter and Diameter ofAny O
46、uter Wiremm in. mm in.Grade 1725I 1250I6.4 0.250 0.025 0.0017.9 0.313 0.038 0.00159.5 0.375 0.051 0.00211.1 0.438 0.064 0.002512.7 0.500 0.076 0.00315.2 0.600 0.102 0.004Grade 1860I 270I7.9 0.313 0.0381 0.00159.5 0.375 0.0508 0.00211.1 0.438 0.0635 0.002512.7 0.500 0.0762 0.00315.2 0.600 0.1016 0.00
47、4(a)(b)FIG. 1 Acceptable Types of Indented WireA 886/A 886M 053document must meet the requirements of the invoked ASTMstandard(s) and conform to any existing EDI agreement be-tween the purchaser and the supplier. Notwithstanding theabsence of a signature, the organization submitting the EDItransmiss
48、ion is responsible for the content of the report.NOTE 4The industry definition as invoked here is: EDI is thecomputer-to-computer exchange of business information in a standardformat such as ANSI ASC X12.14. Packaging and Marking14.1 The strand shall be furnished on reels or in compactcoils having a minimum core diameter of 600 mm (24 in.),unless otherwise specified by the purchaser. Lengths on reels orin reelless packs shall be as agreed upon at the time ofpurchase. The strand shall be well protected against mechani-cal injury in shipping as agreed upon at the time of purchase.Each ree
