1、Designation: A 996/A 996M 06aStandard Specification forRail-Steel and Axle-Steel Deformed Bars for ConcreteReinforcement1This standard is issued under the fixed designationA 996/A 996M; the number immediately following the designation indicates the yearof original adoption or, in the case of revisio
2、n, 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 rail-steel and axle-steel barsfor concrete reinforcement. Three types of pr
3、oduct 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;
4、 manufacturers 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 sym
5、bol” 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, respec
6、tively.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 A 996) or SI units (Specifica-tion A 996M).1.6 The values stated in either inch-pound units or SI unitsare to be regarded as stan
7、dard. 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 w
8、ith its 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:2A 370 Test Methods and Definitions for Mechanical Testingof Steel
9、 ProductsA 700 Practices for Packaging, Marking, and LoadingMethods for Steel Products for ShipmentE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 Military Standard:MIL-STD-129 Marking for Shipment and Storage32.3 Federal Standard:Fed. Std. No. 1
10、23 Marking for Shipment (Civil Agencies)33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 deformed bar, nsteel bar with transverse protru-sions; a bar that is intended for use as reinforcement inreinforced concrete construction.3.1.1.1 DiscussionThe surface of the bar is provid
11、ed withlugs or protrusions that inhibit longitudinal movement of thebar relative to the concrete surrounding the bar in suchconstruction. The lugs or protrusions conform to the provisionsof this specification.3.1.2 deformations, nprotrusions on a deformed bar.3.1.3 rib, nlongitudinal protrusion on a
12、 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 notlimited to, the following.4.1.1 Quantity (weight) mass,1This specification is
13、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 May 1, 2006. Published May 2006. Originallyapproved in 1998. Last previous edition approved in 2006 as A 996
14、/A 996M 06.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order De
15、sk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. Or visit: http:/assist.daps.dla.mil/online.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United S
16、tates.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, and4.1.8 Certified mill test reports (if desired).5. Materials and Manufacture5.1 The bars shal
17、l 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 quality” shall be substituted.6. Carbon Determination6.1 For axle-steel product, the manufacture
18、r shall make adetermination for the carbon content of each axle received formanufacture into reinforcing bars. Based on these carbondeterminations, all steel axles shall be stocked for subsequentrolling in separated lots by carbon range. The ranges of carbonshall be determined by the manufacturer as
19、 those best suited tomeet the mechanical requirements.6.2 When requested 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
20、 on opposite sides ofthe bar shall be similar in size, shape, and 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
21、 deformations shallreverse alternately in direction from those on 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 diamet
22、er of the bar.7.4 The overall length of the deformations shall be 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
23、 ends. Thesummation of the gaps shall not exceed 25 % of the nominalperimeter 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 deformati
24、ons shallconform to the requirements prescribed in Table 1.8. Measurements 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 be
25、gin from a point on adeformation at the beginning of the first space to a correspond-ing point on a deformation after the last included space.Spacing measurments shall not be made over a bar areacontaining bar marking symbols involving letters or numbers.8.2 The average height of deformations shall
26、be determinedfrom measurements made on not less than two typical 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 circumferenti
27、al cover-age, or excessive spacing of deformations shall not constitutecause 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 rej
28、ectionshall be made on the basis of measurements if fewer than 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
29、 or shipping order.9. Tensile Requirements9.1 The material, as 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 deter
30、mined by the drop of thebeam or halt in the gage of the testing machine.9.2.2 Where the steel tested does not have a well-definedyield point, the yield strength shall be determined at extensionunder load using an autographic diagram method or anTABLE 1 Deformed Bar Designation Numbers, Nominal Weigh
31、ts Masses, Nominal Dimensions, and Deformation RequirementsBar DesignationNo.ANominal Weight,lb/ft Nominal Mass,kg/mNominal DimensionsBDeformation Requirements, in. mmDiameter, in. mmCross-SectionalArea in.2mm2Perimeter, in. mmMaximum AverageSpacingMinimum AverageHeightMaximum Gap(Chord of 12.5 % of
32、Nominal Perimeter)3 10 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
33、.525 13.3 0.038 0.97 0.286 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 9.7ABar numbers are based on the number of eighths of an inch included in the nominal diameter of the bars bar numb
34、ers approximate the number of millimeters of thenominal diameter of the bar.BThe nominal dimensions of a deformed bar are equivalent to those of a plain round bar having the same weight mass per foot meter as the deformed bar.A 996/A 996M 06a2extensometer as described in 14.1.2 and 14.1.3 of Test Me
35、thodsand Definitions A 370. The strain shall be 0.5 % within thegage length.9.3 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 requ
36、irements for degree of bending and sizes ofpins 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 bendin
37、g operation.10.2.2 Unrestricted movement of the 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 testi
38、ng, such as placing a specimenacross two pins 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 sha
39、ll be evaluated on thebasis of nominal weight 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 m
40、ass of anydeformed bar be cause for rejection.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 wi
41、rebrushed test are not less than requirements 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
42、not limitedto, laps, seams, slivers, cooling or casting cracks, and mill orguide marks.13. Test Specimens13.1 All mechanical tests shall be conducted in accordancewith Test Methods and DefinitionsA 370, includingAnnexA9.13.2 Tension test specimens shall be the full section of baras rolled.13.3 The u
43、nit stress determinations on full-size specimensshall 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 weightm
44、ass and spacing, height, and gap of deformations 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, withi
45、n 1000 psi7 MPa of the required yield strength, 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 ben
46、d test fails for reasons other than mechanicalreasons 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 specim
47、ens that are at air temperature but not lessthan 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.
48、15.4 If the original test or any of the random 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
49、half of the gage length, as indicated by scribe markson the specimen before testing,TABLE 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 mm, min, % Rail Symboland R ABar Designation no. 3 10 11 6 6 84, 5, 6 13, 16, 19 12 7 6 87
