1、Standard Specification for Deformed and Plain Carbon and Low-Alloy Steel Bars for Concrete Reinforcement AASHTO Designation: M 31M/M 31-171Technical Section: 4f, Metals Release: Group 2 (June 2017) ASTM Designation: A615/A615M-12 American Association of State Highway and Transportation Officials 444
2、 North Capitol Street N.W., Suite 249 Washington, D.C. 20001TS-4f M 31M/M 31-1 AASHTO Standard Specification for Deformed and Plain Carbon and Low-Alloy Steel Bars for Concrete Reinforcement AASHTO Designation: M 31M/M 31-171Technical Section: 4f, Metals Release: Group 2 (June 2017) ASTM Designation
3、: A615/A615M-12 1. SCOPE 1.1. This specification covers deformed and plain carbon and low-alloy steel concrete reinforcement bars in cut lengths or coils. Steel bars containing alloy additions, such as with the AISI and SAE series of alloy steels, are permitted if the resulting product meets all the
4、 other requirements of this specification. The standard sizes and dimensions of deformed bars and their number designations shall be those listed in Table 1. The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in
5、 tables and figures) shall not be considered as requirements of this specification. 1.2. Bars are of four minimum yield strength levels: namely, 280 MPa 40,000 psi, 420 MPa 60,000 psi, 520 MPa 75,000 psi, and 550 MPa 80,000 psi, designated as Grade 280 40, Grade 420 60, Grade 520 75, and Grade 550 8
6、0, respectively. Bars that have carbon contents limited to 0.30 percent or less, and that meet the carbon requirements of this specification, shall be designated as Type W. Bars that have carbon contents greater than 0.30 percent shall be designated as Type S. 1.3. Hot-rolled plain rounds, in sizes
7、up to and including 63.5 mm 21/2in. in diameter in coils or cut lengths, when specified for dowels, spirals, and structural ties or supports, shall be furnished under this specification in Grade 280 40, Grade 420 60, Grade 520 75, and Grade 550 80. For ductility properties (elongation and bending),
8、test provisions of the nearest smaller nominal diameter deformed bar size shall apply. Requirements providing for deformations and marking shall not be applicable. 1.4. Welding of the material in this specification should be approached with caution since no specific provisions have been included to
9、enhance its weldability. When the steel is to be welded, a welding procedure suitable for the chemical composition and intended use or service should be used (Note 1). Note 1The use of the latest edition of ANSI/AWS D1.4 is recommended for welding reinforcing bars. This document describes the proper
10、 selection of the filler metals and preheat/interpass temperatures, as well as performance and procedure qualification requirements. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4f M 31M/M 31-2 AAS
11、HTO Table 1Deformed Bar Designation Numbers, Nominal Masses, Nominal Dimensions, and Deformation Requirements Nominal DimensionsaDeformation Requirements, mm in. Bar Designation No.bNominal Mass, kg/m lb/ft Diameter, mm in. Cross- Sectional Area, mm2in.2 Perimeter, in. mm Maximum Average Spacing Min
12、imum 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 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
13、 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 0.050 9.7 0.383 29 9 5.060 3.400 28.7 1.128 645 1.00 90.0 3.544 20.1
14、0.790 1.42 0.056 10.9 0.431 32 10 6.404 4.303 32.3 1.270 819 1.27 101.3 3.990 22.6 0.889 1.63 0.064 12.4 0.487 36 11 7.907 5.313 35.8 1.410 1006 1.56 112.5 4.430 25.1 0.987 1.80 0.071 13.7 0.540 43 14 11.38 7.65 43.0 1.693 1452 2.25 135.1 5.32 30.1 1.185 2.16 0.085 16.5 0.648 57 18 20.24 13.60 57.3
15、2.257 2581 4.00 180.1 7.09 40.1 1.58 2.59 0.102 21.9 0.864 64 20 24.84 16.69 63.5 2.500 3167 4.91 199.5 7.85 44.5 1.75 2.86 0.113 24.3 0.957 aThe nominal dimensions of a deformed bar are equivalent to those of a plain round bar having the same mass per meter as the deformed bar. The nominal dimensio
16、ns of a deformed bar are equivalent to those of a plain round bar having the same weight per foot as the deformed bar. bBar numbers are based on the number of eighths of an inch included in the nominal diameter of the bars. Bar designation numbers approximate the number of millimeters of the nominal
17、 diameter of the bar. 1.5. This specification is applicable for orders in either SI units (M 31M) or in inch-pound units (M 31). SI units and inch-pound units are not necessarily equivalent; therefore, each system must be used independently of the other. Combining values from the two systems may res
18、ult in non-conformance with the specification. Inch-pound units are shown in brackets in the text for clarity, but they are the applicable values when the material is ordered to M 31. 1.6. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is th
19、e responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: T 244, Mechanical Testing of Steel Products T 285, Bend Test for Bars for Concrete
20、 Reinforcement 2.2. ASTM Standards: A6/A6M, Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling A510/A510M, Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Carbon Steel, and Alloy Steel A700-05, Stand
21、ard Practices for Packaging, Marking, and Loading Methods for Steel Products for Shipment (withdrawn 2014) A706/A706M, Standard Specification for Deformed and Plain Low-Alloy Steel Bars for Concrete Reinforcement A751, Standard Test Methods, Practices, and Terminology for Chemical Analysis of Steel
22、Products E29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4f M 31M/M 31-3 AASHTO 2.3. Milit
23、ary Standards: MIL-STD-129, Marking for Shipment and Storage MIL-STD-163, Steel Mill Products Preparation for Shipment and Storage 2.4. Federal Standard: Fed. Std. No. 123, Marking for Shipment (Civil Agencies) 2.5. AWS Standard: ANSI/AWS D1.4, Structural Welding CodeReinforcing Steel 3. TERMINOLOGY
24、 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 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
25、 with lugs or protrusions that inhibit longitudinal movement of the bar relative to the concrete surrounding the bar in such construction. The lugs or protrusions conform to the provisions of this specification. 3.1.3. plain barsteel bar without protrusions. 3.1.4. riblongitudinal protrusion on a de
26、formed bar. 4. ORDERING INFORMATION 4.1. Orders for carbon or low-alloy steel bars for concrete reinforcement under this specification shall contain the following information: 4.1.1. Quantity (mass) weight, 4.1.2. Deformed and plain, 4.1.3. Bar designation number (size) of deformed bars, or diameter
27、 of plain bars, 4.1.4. Cut length or coils, 4.1.5. Grade, 4.1.6. Type S or Type W, and 4.1.7. AASHTO designation and year of issue. 4.2. The purchaser shall have the option to specify additional requirements, including but not limited to, the following: 4.2.1. Certified mill test reports for Type S
28、bars, if desired (see Section 19); 4.2.2. Require bars in each bundle to be supplied from a single heat (see Section 19.1); 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4f M 31M/M 31-4 AASHTO 4.2.3
29、. Special packaging or marking requirements (see Section 21); 4.2.4. Domestic origin; and 4.2.5. Other special requirements, if any. 5. MATERIAL AND MANUFACTURE 5.1. The bars shall be rolled from properly identified heats of mold cast or strand cast steel using any commercially accepted steelmaking
30、process. The producer shall have the option to manufacture the bars either by hot rolling, or thermal mechanical processing, or quench and tempering, whereby the selected process enables the requirements of this specification to be satisfied. 6. CHEMICAL REQUIREMENTS 6.1. The chemical analysis of ea
31、ch heat of steel shall be determined in accordance with ASTM A751. The manufacturer shall perform the analysis on test samples taken preferably during the pouring of the heat. 6.1.1. For Type S bars, the percentages of carbon, manganese, phosphorus, and sulfur shall be determined. The phosphorus con
32、tent thus determined shall not exceed 0.06 percent. 6.1.1.1. A chemical verification analysis may be made by the purchaser from finished Type S bars. The phosphorus content determined shall not exceed 0.075 percent. 6.1.2. For Type W bars, the percentages of carbon, manganese, phosphorus, sulfur, an
33、d silicon shall be determined and reported. If any other alloying elements are intentionally added to the heat to produce the required properties for Type W bars, such as copper, nickel, chromium, molybdenum, vanadium, niobium, titanium, or boron, they shall also be determined. 6.1.2.1. The maximum
34、heat and verification (check) analysis allowable percentages for carbon, manganese, phosphorus, sulfur and silicon are as shown in Table 2. Table 2Chemical Requirements, SI Units Element Heat Analysis, % max Verification Analysis, % max Carbon 0.30 0.33 Manganese 1.50 1.56 Phosphorus 0.035 0.044 Sul
35、fur 0.045 0.053 Silicon 0.50 0.55 6.1.3. For Type W bars, the heat analysis shall be such that the carbon equivalent (C.E.) does not exceed 0.55 percent, as calculated by the following formula: % Mn % Cu % Ni % Cr % Mo % VC.E. % C6 40 20 10 50 10=+ + 7. REQUIREMENTS FOR DEFORMATIONS 7.1. Deformation
36、s shall be spaced along the bar at substantially uniform distances. The deformations on opposite sides of the bar shall be similar in size, shape, and pattern. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable
37、 law.TS-4f M 31M/M 31-5 AASHTO 7.2. The deformations shall be placed with respect to the axis of the bar so that the included angle is not less than 45 degrees. Where the line of deformations forms an included angle with the axis of the bar from 45 to 70 degrees inclusive, the deformations shall alt
38、ernately reverse in direction on each side, or those on one side shall be reversed in direction from those on the opposite side. Where the line of deformation is over 70 degrees, a reversal in direction is not required. 7.3. The average spacing or distance between deformations on each side of the ba
39、r shall not exceed seven tenths of the nominal diameter of the bar. 7.4. The overall length of deformations shall be such that the gap (measured as a cord) 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 w
40、idth 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 perimeter 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 t
41、o the requirements prescribed in Table 1. 8. MEASUREMENTS OF DEFORMATIONS 8.1. The average spacing of deformations shall be determined by 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 p
42、oint on a deformation at the beginning of the first space to a corresponding point on a deformation after the last included space. Spacing 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 dete
43、rmined from measurements made on not less than two typical deformations. Determinations shall be based on three measurements per deformation, 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
44、coverage, or excessive spacing of deformations shall not constitute cause for rejection unless it has been clearly established by determinations on each lot (Note 2) tested that typical deformation height, gap, or spacing do not conform to the minimum requirements prescribed in Section 7. No rejecti
45、on may be made on the basis of measurements if fewer than ten adjacent deformations on each side of the bar are measured. Note 2A lot is defined as all the bars of one bar number and pattern of deformation contained in an individual shipping release or shipping order. 9. TENSILE REQUIREMENTS 9.1. Fo
46、r Type A and Type W materials, as represented by the test specimens, shall conform to the requirements for tensile properties prescribed in Table 3. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4f
47、M 31M/M 31-6 AASHTO Table 3Tensile Requirements, SI Units Type SGrade 280 40aType S Grade 420 60 Type S Grade 520 75 Type S Grade 550 80 Tensile strength, min MPa psi 420 60,000 620 90,000 690 100,000 725 105,000 Yield strength, min, MPa psi 280 40,000 420 60,000 520 75.000 550 80,000 Elongation in
48、200 mm, min % BarDesgatoN.10 3 11 9 7 7 13, 16 4, 5 12 9 7 7 19 6 12 9 7 7 22, 25 7, 8 8 7 7 29, 32, 36 9, 10, 11 7 6 6 43, 57 14, 18 7 6 6 TypeWGrade 280 40aType W Grade 420 60 Type W Grade 520 75 Type W Grade 550 80 Tensile strength, min MPa psi 420 60,000b620 90,000b690 100,000b725 105,000bYield strength, min, MPa psi 280 40,000 420 60,000 520 75.000 550 80,000 Yield strength, max , MPa psi 540 78,000 675 98,000 Elongation in 200 mm, min % BarDesigntoN.10 3 15 14 12 12 13, 16 4, 5 16 14 12 12 19 6 16 14 12 12 22,
