1、Standard Specification for Rail-Steel and Axle-Steel Deformed Bars for Concrete Reinforcement AASHTO Designation: M 322M/M 322-10 (2015) ASTM Designation: A996/A996M-09 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001
2、TS-4g M 322M/M 322-1 AASHTO Standard Specification for Rail-Steel and Axle-Steel Deformed Bars for Concrete Reinforcement AASHTO Designation: M 322M/M 322-10 (2015) ASTM Designation: A996/A996M-09 1. SCOPE 1.1. This specification covers rail-steel and axle-steel bars for concrete reinforcement. Thre
3、e types of product are included, designated with a “rail symbol” and an “R” for bars made of rail-steel and with an “A” for bars made of axle-steel. The standard sizes and dimensions of deformed bars and their number designations are given in Table 1. All sizes and grades of all types may not be rea
4、dily available; manufacturers should be consulted to verify availability. 1.2. The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes, excluding those in tables and figures, shall not be considered as requirements of the specificati
5、on. 1.3. Type “rail symbol” and Type R are of two minimum yield levels, namely 350 MPa 50,000 psi and 420 MPa 60,000 psi, designated as Grade 350 50 and Grade 420 60, respectively. Type A is of two minimum yield levels, namely 300 MPa 40,000 psi and 420 MPa 60,000 psi, designated as Grade 300 40 and
6、 Grade 420 60. 1.4. The weldability of the steel is not a requirement of this specification. 1.5. This specification is applicable for orders in either SI units (M 322M) or inch-pound units (M 322). 1.6. The values stated in either SI units or inch-pound units are to be regarded as standard. Within
7、the text, the inch-pound units are shown in brackets. The values stated must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. 1.7. This standard does not purport to address all of the safety concerns, if any, associated wi
8、th its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplicati
9、on is a violation of applicable law.TS-4g M 322M/M 322-2 AASHTO Table 1Deformed Bar Designation Numbers, Nominal Masses Weights, Nominal Dimensions, and Deformation Requirements Nominal DimensionsaDeformation Requirements, mm Bar Designation No. Nominal Mass Weight, kg/m lb/ft Diameter, mm in. Cross
10、- Sectional Area, mm2in.2 Perimeter, mm in. Maximum Average Spacing Minimum Average Height Maximum Gap (Chord of 12.5% of Nominal Perimeter) 10 3 0.560 0.376 9.5 0.375 71 0.11 29.9 1.178 6.7 0.262 0.38 0.015 3.6 0.143 13 4 0.994 0.668 12.7 0.500 129 0.20 39.9 1.571 8.9 0.350 0.51 0.020 4.9 0.191 16
11、5 1.552 1.043 15.9 0.625 199 0.31 49.9 1.963 11.1 0.437 0.71 0.028 6.1 0.239 19 6 2.235 1.502 19.1 0.750 284 0.44 59.8 2.356 13.3 0.525 0.97 0.038 7.3 0.286 22 7 3.042 2.044 22.2 0.875 387 0.60 69.8 2.749 15.5 0.612 1.12 0.044 8.5 0.334 25 8 3.973 2.670 25.4 1.000 510 0.79 79.8 3.142 17.8 0.700 1.27
12、 0.050 9.7 0.383 aThe nominal dimensions of a deformed bar are equivalent to those of a plain round bar having the same mass weight per meter foot as the deformed bar. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standard: T 244, Mechanical Testing of Steel Products 2.2. ASTM Standards: A700-05, Standard Pra
13、ctices for Packaging, Marking, and Loading Methods for Steel Products for Shipment (withdrawn 2014) E29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications 2.3. Military Standards: MIL-STD-129, Marking for Shipment and Storage MIL-STD-163, Steel
14、Mill Products Preparation for Shipment and Storage 2.4. Federal Standard: Fed. Std. No. 123, Marking for Shipment (Civil Agencies) 3. TERMINOLOGY 3.1. Description of Terms Specific to This Standard: 3.1.1. deformationstransverse protrusions on a deformed bar. 3.1.2. deformed barsteel bar with transv
15、erse protrusions; a bar that is intended for use as reinforcement in reinforced concrete construction. 3.1.2.1. DiscussionThe surface of the bar is provided with lugs or protrusions that inhibit longitudinal movement of the bar relative to the concrete surrounding the bar in such construction. The l
16、ugs or protrusions conform to the provisions of this specification. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 322M/M 322-3 AASHTO 3.1.3. riblongitudinal protrusion on a deformed bar. 4. ORD
17、ERING INFORMATION 4.1. It shall be the responsibility of the purchaser to specify all requirements that are necessary for material ordered to this specification. Such requirements shall include, but are not limited to, the following: 4.1.1. Quantity (mass) weight, 4.1.2. Name of material (rail-steel
18、 or axle-steel deformed bars 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. AASHTO designation and year of issue, and 4.1.8. Certified mill test reports (if desired). (See Section 18.) 5. MATERIAL AND MANUFACTURE 5.1. The bars shall be
19、rolled from standard section Tee-rails or from carbon-steel axles for railway cars and locomotives. No other materials, such as those known by the terms “rerolled, rail-steel equivalent, and rail-steel quality,” shall be substituted. 6. CARBON DETERMINATION 6.1. For axle-steel product, the manufactu
20、rer shall make a determination for the carbon content of each axle received for manufacture into reinforcing bars. Based on these carbon determinations, all steel axles shall be stocked for subsequent rolling in separated lots by carbon range. The ranges of carbon shall be determined by the manufact
21、urer as those best suited to meet the mechanical requirements. 6.2. When requested by the purchaser, the manufacturer shall report the carbon range for each lot of bars furnished. 7. REQUIREMENTS OF DEFORMATIONS 7.1. Deformations shall be spaced along the bar at substantially uniform distances. The
22、deformations on opposite sides of the bar shall be similar in size, shape, and pattern. 7.2. The deformations shall be placed with respect to the axis of the bar so that the include angle is not less than 45 degrees. Where the line of deformations forms an include angle with the axis of the bar from
23、 45 degrees to 70 degrees inclusive, the deformations shall alternately reverse in direction from those on the opposite side. Where the line of deformation is greater than 70 degrees, a reversal in direction shall not be required. 2015 by the American Association of State Highway and Transportation
24、Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 322M/M 322-4 AASHTO 7.3. The average spacing or distance between deformations on each side of the bar shall not exceed seven-tenths of the nominal diameter of the bar. 7.4. The overall length of deformations shall be
25、 such that the gap between the ends of the deformations shall not exceed 12.5 percent of the nominal perimeter of the bar. Where the ends terminate in a rib, the width of the rib shall be considered as the gap between these ends. The summation of the gaps shall not exceed 25 percent of the nominal p
26、erimeter of the bar. The nominal perimeter of the bar shall be 3.1416 times the nominal diameter. 7.5. The spacing, height, and gap of deformations shall conform to the requirements prescribed in Table 1. 8. MEASUREMENTS OF DEFORMATIONS 8.1. The average spacing of deformations shall be determined by
27、 measuring the length of a minimum of ten spaces and dividing that length by the number of spaces included in the measurement. The measurement shall begin from a point on a deformation at the beginning of the first space to a corresponding point on a deformation after the last included space. Spacin
28、g measurements shall not be made over a bar area containing bar marking symbols involving letters or numbers. 8.2. The average height of deformations shall be determined from measurements made on not fewer than two typical deformations. Determinations shall be based on three measurements per deforma
29、tion, one at the center of the overall length and the other two at the quarter points of the overall length. 8.3. Insufficient height, insufficient circumferential coverage, or excessive spacing of deformations shall not constitute cause for rejection unless it has been clearly established by determ
30、inations on each lot (Note 1) tested that typical deformation height, gap, or spacing do not conform to the minimum requirements prescribed in Section 7. No rejection may be made on the basis of measurements if fewer than ten adjacent deformations on each side of the bar are measured. Note 1As used
31、within the intent of Sections 8.3 and 14.1, the term “lot” shall mean all the bars of one bar number and pattern of deformations contained in an individual shipping release or shipping order. 9. TENSILE REQUIREMENTS 9.1. The material, as represented by the test specimens, shall conform to the requir
32、ements for tensile properties prescribed in Table 2. 9.2. The yield point or yield strength shall be determined by one of the following methods: 9.2.1. The yield point shall be determined by the drop of the beam or halt in the gauge of the testing machine. 9.2.2. Where the steel tested does not exhi
33、bit a well-defined yield point, the yield strength shall be determined by the offset method (0.2 percent offset), as described in T 244 (Section 14.2.1). 9.3. The percentage of elongation shall be as prescribed in Table 2. 2015 by the American Association of State Highway and Transportation Official
34、s.All rights reserved. Duplication is a violation of applicable law.TS-4g M 322M/M 322-5 AASHTO Table 2Tensile Requirements Gradea 300 40 Grade 350 50 Grade 420 60 Tensile strength, min, MPa psi 500 70,000 550 80,000 600 90,000 Yield strength, min, MPa psi 300 40,000 350 50,000 400 60,000 Elongation
35、 in 200 mm 8 in., min, percent Bar Designation No.: Rail Symbol and Type R Type A 10 3 11 6 6 8 13, 16, 19 4, 5, 6 12 7 6 8 22 7 11 6 5 8 25 8 10 5 4.5 7 aSizes 10 through 19 may not be readily available; manufacturers should be consulted to verify availability. 10. BENDING REQUIREMENTS 10.1. The be
36、nd-test specimen shall withstand being bent around a pin without cracking on the outside of the bent portion. The requirements for degree of bending and sizes of pins are prescribed in Table 3. Table 3Bend-Test Requirements Bar Designation No. Pin Diameter for Bend TestsaType Rail Symbol Type R Type
37、 A 10, 13, 16 3, 4, 5 6db31/2d 31/2d 19, 22, 25 6, 7, 8 6d 5d 5d aTest bends 180. bd = nominal diameter of specimen. 10.2. The bend test shall be made on specimens of sufficient length to ensure free bending and with an apparatus that provides the following: 10.2.1. Continuous and uniform applicatio
38、n of force throughout the duration of the bending operation; 10.2.2. Unrestricted movement of the specimen at points of contact with the apparatus and bending around a pin free to rotate; 10.2.3. Close wrapping of the specimen around the pin during the bending operation. 10.3. It shall be permissibl
39、e to use other acceptable, more severe methods of bend testing, such as placing a specimen across two pins free to rotate and applying the bending force with a fixed pin. When failures occur under more severe methods, retests shall be permitted under the bend-test method prescribed in Section 10.2.
40、11. PERMISSIBLE VARIATION IN MASS WEIGHT 11.1. Deformed reinforcing bars shall be evaluated on the basis of nominal mass weight. The mass weight determined using the measured mass weight of the test specimen and rounding in accordance with ASTM E29 shall be at least 94 percent of the applicable mass
41、 weight per unit length prescribed in Table 1. In no case shall excess mass overweight of any deformed bar be cause for rejection. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 322M/M 322-6 AAS
42、HTO 12. FINISH 12.1. The bars shall be free of detrimental surface imperfections. 12.2. Rust, seams, surface irregularities, or mill scale shall not be cause for rejection, provided the mass weight, dimensions, cross-sectional area, and tensile properties of a hand wire-brushed test are not less tha
43、n the requirements of this specification. 12.3. Surface imperfections or flaws other than those specified in Section 12.2 shall be considered detrimental when specimens containing such imperfections fail to conform to either tensile or bending requirements. Examples include, but are not limited to,
44、laps, seams, slivers, cooling or casting cracks, and mill or guide marks. 13. TEST SPECIMENS 13.1. All mechanical tests shall be conducted in accordance with T 244, including Annex A9. 13.2. Tension test specimens shall be the full section of bar as rolled. 13.3. The unit stress determinations on fu
45、ll-sized specimens shall be based on the nominal bar area. 13.4. The bend-test specimens shall be the full section of the bar as rolled. 14. NUMBER OF TESTS 14.1. For bar sizes No. 10 to No. 25 No. 3 to No. 8 inclusive, one tension test and one bend test shall be made from each lot (Note 1) of 9 Mg
46、10 tons or fraction thereof. Each lot of rails (“rail symbol” or “R”) shall not vary more than 5 kg/m 10 lb/yd of nominal mass weight. Each lot of axles (Type A) shall be assorted in groups as specified in Section 6. 15. RETESTS 15.1. If results of an original tension specimen fail to meet the speci
47、fied minimum requirements and are within 14 MPa 2000 psi of the required tensile strength, within 7 MPa 1000 psi of the required yield point, or within two percentage points of the required elongation, a retest shall be permitted on two random specimens for each original tension specimen failure fro
48、m the lot. Both retest specimens shall meet the requirements of this specification. 15.2. If a bend test fails for reasons other than mechanical reasons or flaws in the specimen as described in Sections 15.4.2 and 15.4.3, a retest shall be permitted on two random specimens from the same lot. Both re
49、test specimens shall meet the requirements of this specification. The retest shall be performed on test specimens that are at air temperature but not less than 16C 60F. 15.3. If a weight mass test fails for reasons other than flaws in the specimen as described in Section 15.4.3, a retest shall be permitted on two random specimens from the same lot. Both retest specimen
