1、Designation: A996/A996M 09aStandard Specification forRail-Steel and Axle-Steel Deformed Bars for ConcreteReinforcement1This standard is issued under the fixed designation A996/A996M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision,
2、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 rail-steel and axle-steel barsfor concrete reinforcement. Three types of produc
3、t are in-cluded, designated with a “rail symbol,” and an “R” for barsmade of rail-steel and with an “A” for bars made of axle-steel.The standard sizes and dimensions of deformed bars and theirnumber designations are given in Table 1. All sizes and gradesof all types may not be readily available; man
4、ufacturers shouldbe consulted to verify availability.1.2 The text of this specification references notes andfootnotes that provide explanatory material. These notes andfootnotes, excluding those in tables and figures, shall not beconsidered as requirements of the specification.1.3 Type “rail symbol”
5、 and Type R are of two minimumyield strength levels, namely 50 000 psi 350 MPa and 60 000psi 420 MPa designated as Grade 50 350 and Grade 60420, respectively. Type A is of two minimum yield levels,namely 40 000 psi 280 MPa and 60 000 psi 420 MPadesignated as Grade 40 280 and Grade 60 420, respective
6、ly.1.4 The weldability of the steel is not a requirement of thisspecification.1.5 This specification is applicable for orders in eitherinch-pound units (Specification A996) or SI units (Specifica-tion A996M).1.6 The values stated in either inch-pound units or SI unitsare to be regarded as standard.
7、Within the text, the SI units areshown in brackets. The values stated must be used indepen-dently of the other. Combining values from the two systemsmay result in nonconformance with the specification.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with it
8、s use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testingof Steel Produc
9、tsA700 Practices for Packaging, Marking, and Loading Meth-ods for Steel Products for ShipmentA751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 Military Standard:3
10、MIL-STD-129 Marking for Shipment and Storage2.3 Federal Standard:3Fed. Std. No. 123 Marking for Shipment (Civil Agencies)3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 deformations, nprotrusions on a deformed bar.3.1.2 deformed bar, nsteel bar with transverse protru-sions; a
11、bar that is intended for use as reinforcement inreinforced concrete construction.3.1.2.1 DiscussionThe surface of the bar is provided withlugs or protrusions that inhibit longitudinal movement of thebar relative to the concrete surrounding the bar in suchconstruction. The lugs or protrusions conform
12、 to the provisionsof this specification.3.1.3 rib, nlongitudinal protrusion on a deformed bar.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specifyall requirements that are necessary for material ordered to thisspecification. Such requirements shall include, but are n
13、otlimited to, the following.4.1.1 Quantity (weight) mass,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 edition approved Oct. 1, 2009. Published Nove
14、mber 2009. Originallyapproved in 1998. Last previous edition approved in 2009 as A996/A996M 09.DOI: 10.1520/A0996_A0996M-09A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information,
15、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:/www.dodssp.daps.mil.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM
16、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.2 Name of material (rail-steel or axle-steel deformedbars for concrete reinforcement),4.1.3 Type,4.1.4 Size,4.1.5 Grade,4.1.6 Packaging (see Section 20),4.1.7 ASTM designation and year of issue, an
17、d4.1.8 Certified mill test reports (if desired).5. Materials and Manufacture5.1 The bars shall be rolled from standard section Tee railsor from carbon steel axles for railway cars and locomotives. Noother materials, such as those known by the terms “rerolled,rail-steel equivalent, and rail-steel qua
18、lity” shall be substituted.6. Carbon Determination6.1 The chemical analysis of the material, as describedbelow, shall be determined in accordance with Test Methods,Practices, and Terminology A751. For axle-steel product, themanufacturer shall make a determination for the carbon contentof each axle r
19、eceived for manufacture into reinforcing bars.Based on these carbon determinations, all steel axles shall bestocked for subsequent rolling in separated lots by carbonrange. The ranges of carbon shall be determined by themanufacturer as those best suited to meet the mechanicalrequirements.6.2 When re
20、quested by the purchaser, the manufacturershall report the carbon range for each lot of bars furnished.7. Requirements for Deformations7.1 Deformations shall be spaced along the bar at substan-tially uniform distances. The deformations on opposite sides ofthe bar shall be similar in size, shape, and
21、 pattern.7.2 The deformations shall be placed with respect to the axisof the bar so that the included angle is not less than 45. Wherethe line of deformations forms an included angle with the axisof the bar from 45 to 70 inclusive, the deformations shallreverse alternately in direction from those on
22、 the opposite side.Where the line of deformations is over 70, reversal indirection shall not be required.7.3 The average spacing or distance between deformationson each side of the bar shall not exceed seven tenths of thenominal diameter of the bar.7.4 The overall length of the deformations shall be
23、 such thatthe gap (measured as a chord) between the ends of thedeformations shall not exceed 12.5 % of the nominal perimeterof the bar. Where the ends terminate in a rib, the width of therib shall be considered as the gap between these ends. Thesummation of the gaps shall not exceed 25 % of the nomi
24、nalperimeter of the bar. Furthermore, the summation of gaps shallnot exceed 25 % of the nominal permeter of the bar. Thenominal perimeter of the bar shall be 3.1416 times the nominaldiameter.7.5 The spacing, height, and gap of deformations shallconform to the requirements prescribed in Table 1.8. Me
25、asurements of Deformation8.1 The average spacing of deformations shall be deter-mined by measuring the length of a minimum of 10 spaces anddividing that length by the number of spaces included in themeasurement. The measurement shall begin from a point on adeformation at the beginning of the first s
26、pace to a correspond-ing point on a deformation after the last included space.Spacing measurements shall not be made over a bar areacontaining bar marking symbols involving letters or numbers.8.2 The average height of deformations shall be determinedfrom measurements made on not less than two typica
27、l defor-mations. Determinations shall be based on three measurementsper deformation, one at the center on the overall length and theother two at the quarter points of the overall length.8.3 Insufficient height, insufficient circumferential cover-age, or excessive spacing of deformations shall not co
28、nstitutecause for rejection unless it has been clearly established bydeterminations on each lot (Note 1) tested that typical defor-mation height, gap, or spacing does not conform to theminimum requirements prescribed in Section 7. No rejectionshall be made on the basis of measurements if fewer than
29、tenadjacent deformations on each side of the bar are measured.NOTE 1As used within the intent of 8.3 and 14.1, the term “lot” shallmean all the bars of one bar number and pattern of deformations containedin an individual shipping release or shipping order.9. Tensile Requirements9.1 The material, as
30、represented by the test specimens, shallconform to the requirements for tensile properties prescribed inTable 2.9.2 The yield point or yield strength shall be determined byone of the following methods.9.2.1 The yield point shall be determined by the drop of thebeam or halt in the gage of the testing
31、 machine.9.2.2 Where the steel tested does not have a well-definedyield point, the yield strength shall be determined by the offsetmethod (0.2 % offset), as described in Test Methods andDefinitions A370 (paragraph 13.2.1).TABLE 1 Deformed Bar Designation Numbers, Nominal Weights Masses, Nominal Dime
32、nsions, and Deformation RequirementsBar Designation No.Nominal Weight,lb/ft Nominal Mass,kg/mNominal DimensionsADeformation Requirements, in. mmDiameter, in. mmCross-SectionalArea in.2mm2Perimeter, in. mmMaximum AverageSpacingMinimum AverageHeightMaximum Gap(Chord of 12.5 % ofNominal Perimeter)3 10
33、0.376 0.560 0.375 9.5 0.11 71 1.178 29.9 0.262 6.7 0.015 0.38 0.143 3.64 13 0.668 0.994 0.500 12.7 0.20 129 1.571 39.9 0.350 8.9 0.020 0.51 0.191 4.95 16 1.043 1.552 0.625 15.9 0.31 199 1.963 49.9 0.437 11.1 0.028 0.71 0.239 6.16 19 1.502 2.235 0.750 19.1 0.44 284 2.356 59.8 0.525 13.3 0.038 0.97 0.
34、286 7.37 22 2.044 3.042 0.875 22.2 0.60 387 2.749 69.8 0.612 15.5 0.044 1.12 0.334 8.58 25 2.670 3.973 1.000 25.4 0.79 510 3.142 79.8 0.700 17.8 0.050 1.27 0.383 9.7AThe nominal dimensions of a deformed bar are equivalent to those of a plain round bar having the same weight mass per foot metre as th
35、e deformed bar.A996/A996M 09a29.3 The percentage of elongation shall be as prescribed inTable 2.10. Bending Requirements10.1 The bend test specimen shall withstand being bentaround a pin without cracking on the outside radius of the bentportion. The requirements for degree of bending and sizes ofpin
36、s are prescribed in Table 3.10.2 The bend test shall be made on specimens of sufficientlength to ensure free bending and with an apparatus whichprovides the following.10.2.1 Continuous and uniform application of forcethroughout the duration of the bending operation.10.2.2 Unrestricted movement of th
37、e specimen at points ofcontact with the apparatus and bending around a pin free torotate.10.2.3 Close wrapping of the specimen around a pin duringthe bending operation.10.3 It shall be permissible to use other acceptable, moresevere methods of bend testing, such as placing a specimenacross two pins
38、free to rotate and applying the bending forcewith a fixed pin. When failures occur under more severemethods, retest shall be permitted under the bend test methodprescribed in 10.2.11. Permissible Variation in Weight Mass11.1 Deformed reinforcing bars shall be evaluated on thebasis of nominal weight
39、mass. The weight mass determinedusing the measured weight mass of the test specimen androunding in accordance with Practice E29, shall be at least94 % of the applicable weight mass per unit length prescribedin Table 1. In no case shall overweight excess mass of anydeformed bar be cause for rejection
40、.12. Finish12.1 The bars shall be free of detrimental surface imperfec-tions.12.2 Rust, seams, surface irregularities, or mill scale shallnot be cause for rejection, provided the weight, dimensions,cross-sectional area, and tensile properties of a hand wirebrushed test are not less than requirements
41、 of this specification.12.3 Surface imperfections or flaws other than those speci-fied in 12.2 shall be considered detrimental when specimenscontaining such imperfections fail to conform to either tensileor bending requirements. Examples include, but are not limitedto, laps, seams, slivers, cooling
42、or casting cracks, and mill orguide marks.13. Test Specimens13.1 All mechanical tests shall be conducted in accordancewith Test Methods and Definitions A370, including Annex A9.13.2 Tension test specimens shall be the full section of baras rolled.13.3 The unit stress determinations on full-size spec
43、imensshall be based on the nominal bar area.13.4 The bend test specimens shall be the full section of thebar as rolled.14. Number of Tests14.1 For all bar sizes, one tension test, one bend test, andone set of dimensional property tests including bar weightmass and spacing, height, and gap of deforma
44、tions shall bemade from each lot (Note 1) of 10 tons 9 mg, or fractionthereof.15. Retests15.1 If the results of an original tension specimen fail tomeet the specified minimum requirements and are within 2000psi 14 MPa of the required tensile strength, within 1000 psi7 MPa of the required yield stren
45、gth, or within two percent-age points of the required elongation, a retest shall be permittedon two random specimens for each original tension specimenfailure from the lot. Both retest specimens shall meet therequirements of this specification.15.2 If a bend test fails for reasons other than mechani
46、calreasons or flaws in the specimen as described in 15.4.2 and15.4.3, a retest shall be permitted on two random specimensfrom the same lot. Both retest specimens shall meet therequirements of this specification. The retest shall be per-formed on test specimens that are at air temperature but not les
47、sthan 60F 16C.15.3 If a weight mass test fails for reasons other than flawsin the specimen as described in 15.4.3, a retest shall bepermitted on two random specimens from the same lot. Bothretest specimens shall meet the requirements of this specifica-tion.15.4 If the original test or any of the ran
48、dom retests failsbecause of any reasons listed in 15.4.1, 15.4.2,or15.4.3, thetest shall be considered an invalid test:15.4.1 The elongation property of any tension test specimenis less than that specified, and any part of the fracture is outsidethe middle half of the gage length, as indicated by sc
49、ribe markson the specimen before testing,NOTE 2Marking specimens with multiple scribe or punch marks canreduce the occurrence of fracture outside or near these marks and the needTABLE 2 Tensile RequirementsGrade 40 280 Grade 50 350 Grade 60 420Tensile strength, 70 000 500 80 000 550 90 000 620min, psi MPaYield strength, 40 000 280 50 000 350 60 000 420min, psi MPaElongation in 8 in. Type200 m
