AASHTO M 31M M 31-2015 Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement.pdf

1、Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement AASHTO Designation: M 31M/M 31-151ASTM Designation: A615/A615M-12 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001TS-4g M 31M/M

2、 31-1 AASHTO Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement AASHTO Designation: M 31M/M 31-151ASTM Designation: A615/A615M-12 1. SCOPE 1.1. This specification covers deformed and plain carbon steel concrete reinforcement bars in cut lengths or coils. Steel

3、 bars containing alloy additions, such as with the AISI and SAE series of alloy steels, are permitted if the resulting product meets all the other requirements of this specification. The standard sizes and dimensions of deformed bars and their number designations shall be those listed in Table 1. Th

4、e 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 this specification. 1.2. Bars are of four minimum yield strength levels: namely, 280 MPa 40,000

5、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 80, respectively. 1.3. Hot-rolled plain rounds, in sizes up to and including 63.5 mm 21/2in. in diameter in coils or cut lengths, when specified for dowels, spir

6、als, 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), test provisions of the nearest smaller nominal diameter deformed bar size shall apply. Requirements prov

7、iding 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 enhance its weldability. When the steel is to be welded, a welding procedure suitable for the chemical c

8、omposition 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 selection of the filler metals and preheat/interpass temperatures, as well as performance and procedure

9、 qualification requirements. 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

10、may result 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. I

11、t 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. Duplication is a viola

12、tion of applicable law.TS-4g M 31M/M 31-2 AASHTO 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

13、Perimeter, in. mm 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 5 1.552 1.043 15.9 0.625

14、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 0.050 9.7 0.383 29 9 5.0

15、60 3.400 28.7 1.128 645 1.00 90.0 3.544 20.1 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

16、2.16 0.085 16.5 0.648 57 18 20.24 13.60 57.3 2.257 2581 4.00 180.1 7.09 40.1 1.58 2.59 0.102 21.9 0.864 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 dimensions of a deformed bar are equivalent t

17、o 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 diameter of the bar. 2. REFERENCED D

18、OCUMENTS 2.1. AASHTO Standards: T 244, Mechanical Testing of Steel Products T 285, Bend Test for Bars for Concrete Reinforcement 2.2. ASTM Standards: A6/A6M, Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling A370, Standard Test Methods

19、 and Definitions for Mechanical Testing of Steel Products A510/A510M, Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Carbon Steel, and Alloy Steel A700-05, Standard Practices for Packaging, Marking, and Loading Methods for Steel Products for Shipment (withdrawn

20、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 Products E29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance wi

21、th Specifications 2.3. Military 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) 2015 by the American Association of State Highway and Transpo

22、rtation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 31M/M 31-3 AASHTO 2.5. AWS Standard: ANSI/AWS D1.4, Structural Welding CodeReinforcing Steel 3. TERMINOLOGY 3.1. Description of Terms Specific to This Standard: 3.1.1. deformationstransverse protrusions on a

23、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 with lugs or protrusions that inhibit longitudinal movement of the bar relative to the concrete surr

24、ounding 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 deformed bar. 4. ORDERING INFORMATION 4.1. It shall be the responsibility of the purchaser to specify a

25、ll requirements that are necessary for material ordered to this specification. Orders for material under this specification should include the following information: 4.1.1. Quantity (mass) weight, 4.1.2. Name of the material (deformed and plain carbon steel bars for concrete reinforcement), 4.1.3. S

26、ize, 4.1.4. Cut length or coils, 4.1.5. Deformed or plain, 4.1.6. Grade, 4.1.7. Packaging (see Section 21), 4.1.8. AASHTO designation and year of issue, and 4.1.9. Certified mill test reports (if desired). (See Section 19.) 5. MATERIAL AND MANUFACTURE 5.1. The bars shall be rolled from properly iden

27、tified heats of mold cast or strand cast steel using the electric-furnace, basic-oxygen, or open-hearth process. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 31M/M 31-4 AASHTO 6. CHEMICAL REQU

28、IREMENTS 6.1. The chemical analysis of each 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. The percentages of carbon, manganese, phosphorus, and sulfur shall be determined. T

29、he phosphorus content thus determined shall not exceed 0.06 percent. 6.2. An analysis may be made by the purchaser from finished bars. The phosphorus content thus determined shall not exceed that specified in Section 6.1 by more than 25 percent. 7. REQUIREMENTS FOR DEFORMATIONS 7.1. Deformations sha

30、ll 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. 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

31、of deformations forms an included angle with the axis of the bar from 45 to 70 degrees inclusive, the deformations shall alternately 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 degree

32、s, a reversal in direction is not required. 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 such that the gap (measured as a cord) between the ends of

33、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 perimeter of the bar. The nominal perime

34、ter 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 measuring the length of a minimum of t

35、en 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. Spacing measurements shall not be made over a

36、 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 less than two typical deformations. Determinations shall be based on three measurements per deformation, one at the center of the overall l

37、ength 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 determinations on each lot (Note 2) tested tha

38、t 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 2A lot is defined as all the bars of one bar numb

39、er and pattern of deformation contained in an individual shipping release or shipping order. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 31M/M 31-5 AASHTO 9. TENSILE REQUIREMENTS 9.1. The mat

40、erial, as represented by the test specimens, shall conform to the requirements for tensile properties prescribed in Table 2. Table 2Tensile Requirements, SI Units Grade 280 40aGrade 420 60aGrade 520 75aGrade 550 80aTensile strength, min MPa psi 420 60,000 620 90,000 690 100,000 725 105,000 Yield str

41、ength, min, MPa psi 280 40,000 420 60,000 520 75.000 550 80,000 Elongation in 200 mm, min % Bar Designation No. 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 aGrade 280 bars are furnished only in sizes 10 through 19. Grade 40 bars a

42、re furnished only in sizes 3 through 6. 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 drop of the beam or halt of the pointer method as described in Section 14.1.1 of T 244. 9.2.2. Where the steel tested does

43、 not have a well-defined yield point, the yield point shall be determined at extension under load using an autographic diagram method or and extensometer as described in Sections 14.1.2 and 14.1.3 of T 244. The extension under load shall be 0.005 mm/mm 0.005 in./in. of gauge length (0.5 percent) for

44、 Grade 280 40 and Grade 420 60 and shall be 0.0035 mm/mm 0.0035 in./in. of gauge length (0.35 percent) for Grade 520 75. 9.3. When material is furnished in coils, the test sample must be straightened prior to placing it in the jaws of the tensile testing machine. Straightening shall be done carefull

45、y to avoid formation of local sharp bends and to minimize cold work. Note 3Insufficient straightening prior to attaching the extensometer can result is lower-than-actual yield strength readings. 9.4. The percentage of elongation shall be as prescribed in Table 2 when tested in accordance with Sectio

46、n 14.4 of T 244. 10. BENDING REQUIREMENTS 10.1. The bend-test specimen shall withstand being bent around a pin without cracking on the outside radius of the bent portion when tested in accordance with T 285. The requirements for angle of bending and sizes of pins are prescribed in Table 3. When mate

47、rial is furnished in coils, the test sample must be straightened prior to placing it in the bend tester. 10.2. The bend test shall be made on specimens of sufficient length to ensure free bending and with apparatus that provides: 10.2.1. Continuous and uniform application of force throughout the dur

48、ation of the bending operation. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4g M 31M/M 31-6 AASHTO 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 is permissible to use more severe methods of bend testing, such as placing a specimen across two pins free to rotate and applying the bending force w