ASTM A706/A706M-22a

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of the standard as published by ASTM is to be considered the official document.
Designation: A706/A706M − 22 A706/A706M − 22a
Standard Specification for
Deformed and Plain Low-Alloy Steel Bars for Concrete
Reinforcement
This standard is issued under the fixed designation A706/A706M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 General—This specification covers deformed and plain low-alloy steel bars in cut lengths and coils for concrete reinforcement
intended for applications where restrictive mechanical properties and chemical composition are required for compatibility with
controlled tensile property applications or to enhance weldability. The standard sizes and dimensions of deformed bars and their
number designations are given in Table 1.
1.2 Grade—Bars are of twothree minimum yield strength levels: namely, 60 000 psi [420 MPa] and MPa], 80 000 psi [550 MPa],
and 100 000 psi [690 MPa] designated as Grade 60 [420] and [420], Grade 80 [550], and Grade 100 [690], respectively.
1.3 Plain bars, in sizes up to and including 2 ⁄2 in. [63.5 mm] in diameter in coils or cut lengths, when ordered, shall be furnished
under this specification. For ductility properties (elongation and bending), 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 Controlled Tensile Properties—This specification limits tensile properties (Table 2) to provide the desired yield/tensile
properties for controlled tensile property applications.
1.5 Welding—This specification limits chemical composition (6.2) and carbon equivalent (6.4) to enhance the weldability of the
material. When this steel is to be welded, a welding procedure suitable for the chemical composition and intended use or service
should be used. The use of the latest edition of AWS D1.4 ⁄D1.4M is recommended. The AWS D1.4/D1.4M Welding Code
describes the proper selection of the filler metals, preheat/interpass temperatures, as well as, performance and procedure
qualification requirements.
NOTE 1—As a result of the 117 000 psi minimum tensile strength for Grade 100 [690], users of this specification should be aware that ACI 318 Type 1
mechanical splice requirements of 125 % of specified yield strength requirements in tension and compression, found in many acceptance criteria, may
result in an invalid mechanical splice qualification or verification test when the tensile strength of the bar is between 117 000 psi and 125 000 psi.
1.6 Annex A2 describes the methods for determination of uniform elongation (El ). Annex A2 is mandatory when Supplementary
u
Requirement S1 is specified by the purchaser (see 4.2.6).
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.05
on Steel Reinforcement.
Current edition approved July 1, 2022Dec. 1, 2022. Published July 2022February 2023. Originally approved in 1974. Last previous edition approved in 20162022 as
A706/A706M – 16.A706/A706M – 22. DOI: 10.1520/A0706_A0706M-22.10.1520/A0706_A0706M-22A.
*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 States
A706/A706M − 22a
TABLE 1 Deformed Bar Designation Numbers, Nominal Weights [Masses], Nominal Dimensions, and Deformation Requirements
A
Nominal Dimensions Deformation Requirements, in. [mm]
Bar
Nominal Weight, lb/ft
Desig-
Maximum Gap
[Nominal Mass,
Diameter, Cross-Sectional Area Perimeter, Maximum Average Minimum Average
nation
(Chord of 12.5 % of
2 2
kg/m]
in. [mm] in. [mm ] in. [mm] Spacing Height
No.
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 [ 3.6]
4 [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 [ 4.9]
5 [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 [ 6.1]
6 [19] 1.502 [ 2.235] 0.750 [19.1] 0.44 [ 284] 2.356 [ 59.8] 0.525 [13.3] 0.038 [0.97] 0.286 [ 7.3]
7 [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 [ 8.5]
8 [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 [ 9.7]
9 [29] 3.400 [ 5.060] 1.128 [28.7] 1.00 [ 645] 3.544 [ 90.0] 0.790 [20.1] 0.056 [1.42] 0.431 [10.9]
10 [32] 4.303 [ 6.404] 1.270 [32.3] 1.27 [ 819] 3.990 [101.3] 0.889 [22.6] 0.064 [1.63] 0.487 [12.4]
11 [36] 5.313 [ 7.907] 1.410 [35.8] 1.56 [1006] 4.430 [112.5] 0.987 [25.1] 0.071 [1.80] 0.540 [13.7]
14 [43] 7.65 [11.38] 1.693 [43.0] 2.25 [1452] 5.32 [135.1] 1.185 [30.1] 0.085 [2.16] 0.648 [16.5]
18 [57] 13.60 [20.24] 2.257 [57.3] 4.00 [2581] 7.09 [180.1] 1.58 [40.1] 0.102 [2.59] 0.864 [21.9]
A
The nominal dimensions of a deformed bar are equivalent to those of a plain round bar having the same weight [mass] per foot [metre] as the deformed bar.
TABLE 2 Tensile Requirements
Grade 60 Grade 80 Grade 100
[420] [550] [690]
Tensile strength, min, 80 000 100 000
A A
psi [MPa] [550] [690]
Tensile strength, min, 80 000 100 000 117 000
psi [MPa] [550] [690] [805]
Yield strength, min, 60 000 80 000 100 000
psi [MPa] [420] [550] [690]
Yield strength, max, 78 000 98 000 118 000
psi [MPa] [540] [675] [815]
Ratio of actual tensile strength to 1.25 1.25 1.17
actual yield strength, min
Elongation in 8 in. [200 mm],
min, %
Bar Designation Nos.
3, 4, 5, 6 [10, 13, 16, 19] 14 12 10
7, 8, 9, 10, 11 [22, 25, 29, 32, 36] 12 12 10
14, 18 [43, 57] 10 10 10
A
Tensile strength shall not be less than 1.25 times the actual yield strength.
1.7 Requirements for alternate bar sizes are presented in Annex A1. The requirements in Annex A1 only apply when specified by
the purchaser (see 4.2.5).
1.8 The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes,
excluding those in tables, shall not be considered as requirements of this specification.
1.9 This specification is applicable for orders in either inch-pound units (Specification A706) or in SI units [Specification A706M].
1.10 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units
are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used
independently of the other. Combining values from the two systems may result in non-conformance with this specification.
1.11 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.12 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
A706/A706M − 22a
2. Referenced Documents
2.1 ASTM Standards:
A6/A6M Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A510/A510M Specification for General Requirements for Wire Rods and Coarse Round Wire, Carbon Steel, and Alloy Steel
A615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement
A700 Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment
A751 Test Methods and Practices for Chemical Analysis of Steel Products
E8/E8M Test Methods for Tension Testing of Metallic Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E290 Test Methods for Bend Testing of Material for Ductility
2.2 AWS Standard:
AWS D1.4 ⁄D1.4M Structural Welding Code—Reinforcing Steel
2.3 U.S. Military Standard:
MIL-STD-129 Marking for Shipment and Storage
2.4 U.S. Federal Standard:
Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
2.5 ACI Building Code:
ACI Code-318 Building Code Requirements for Structural Concrete and Commentary
2.6 Canadian Standards Association:
G30.18 Carbon steel bars for concrete reinforcement
2.7 ISO Standards:
ISO 15630–1 Steel for the reinforcement and prestressing of concrete – Test methods – Part 1: Reinforcing bars, rods and wire
3. Terminology
3.1 Definitions of Terms Specific to This Specification:Standard:
3.1.1 deformations, n—transverse protrusions on a deformed bar.
3.1.2 deformed bar, n—steel bar with protrusions; a bar that is intended for use as reinforcement in reinforced concrete and related
construction.
3.1.2.1 Discussion—
The 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 lugs or protrusions conform to the provisions of this specification.
3.1.3 plain bar, n—steel bar without protrusions.
3.1.4 plastic component of uniform elongation, El [%], n—the measurement of plastic strain taken remote from the break to avoid
localized necking of the bar, used for the determination of uniform elongation (see Annex A2).
3.1.5 rib, n—longitudinal protrusion on a deformed bar.
3.1.6 uniform elongation, El [%]—the elongation determined at the maximum force sustained by the test piece just prior to
u
necking or fracture, or both (see Test Methods E8/E8M).
4. Ordering Information
4.1 Orders for low-alloy steel bars for concrete reinforcement under this specification shall contain the following information:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Welding Society (AWS), 8669 NW 36 Street, #130, Miami, FL 33166-6672, http://www.aws.org.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://www.dodssp.daps.mil.
Available from American Concrete Institute, 38800 Country Club Dr., Farmington Hills, MI, 48331-3439, http://www.concrete.org.
Available from Canadian Standards Association (CSA), 178 Rexdale Blvd., Toronto, ON M9W 1R3, Canada, http://www.csagroup.org.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland,
https://www.iso.org.
A706/A706M − 22a
4.1.1 Quantity (weight) [mass],
4.1.2 Deformed or plain,
4.1.3 Bar designation number (size) of deformed bars, or nominal diameter (size) of plain bars,
4.1.4 Cut lengths or coils,
4.1.5 Grade, and
4.1.6 ASTM 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 Requirements for inspection (17.1),
4.2.2 Special package marking requirements (20.2),
4.2.3 Require bars in each bundle to be supplied from a single heat (16.1),
4.2.4 Other special requirements, if any, and
4.2.5 Optional requirements of Annex A1, if applicable.
4.2.6 Supplementary requirements, if applicable.
5. Material and Manufacture
5.1 The bars shall be processed from properly identified heats of mold-cast or strand-cast steel. The steel shall be made by any
commercially accepted process.
6. Chemical Composition
6.1 The chemical analysis of each heat shall be determined in accordance with Test Methods, Practices, and Terminology A751.
The manufacturer shall make the analysis on test samples taken preferably during the pouring of the heat. The percentages of
carbon, manganese, phosphorus, sulfur, silicon, copper, nickel, chromium, molybdenum, and vanadium shall be determined.
6.2 The chemical composition as shown by heat analysis shall be limited by the following:
Element max, %
Carbon 0.30
Manganese 1.50
Phosphorus 0.035
Sulfur 0.045
Silicon 0.50
6.3 Choice and use of alloying elements, combined with carbon, phosphorus, and sulfur to produce the mechanical properties
prescribed in Table 2 and Table 3, shall be made by the manufacturer. Elements commonly used include manganese, silicon,
copper, nickel, chromium, molybdenum, vanadium, columbium, titanium, and zirconium.
6.4 The heat analysis shall be such as to provide a carbon equivalent (C.E.) not exceeding 0.55 % as calculated by the following
formula:
% Mn % Cu % Ni % Cr % Mo % V
C.E.5 %C1 1 1 1 2 2 (1)
6 40 20 10 50 10
A706/A706M − 22a
TABLE 3 Bend Test Requirements
Pin Diameter for 180° Bend Tests
Bar Designation No.
Grade 60 Grade 80 Grade 100
[420] [550] [690]
A A
1 1
3, 4, 5 [10, 13, 16] 3d 3 ⁄2d 3 ⁄2d
6, 7, 8 [19, 22, 25] 4d 5d 5d
9, 10, 11 [29, 32, 36] 6d 7d 7d
14, 18 [43, 57] 8d 9d 9d
A
d = nominal diameter of specimen.
6.5 Product (Check) Verification Analysis—A product check analysis made by the purchaser shall not exceed the following
percentages:
Element max, %
Carbon 0.33 %
Manganese 1.56 %
Phosphorus 0.043 %
Sulfur 0.053 %
Silicon 0.55 %
7. Requirements for Deformations
7.1 Deformations 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.
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°. Where the
line of deformations forms an included angle with the axis of the bar from 45 to 70°, inclusive, the deformations shall reverse
alternately 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°, a reversal in direction shall not be required.
7.3 The average spacing or distance between deformations on each side of the bar shall not exceed ⁄10 of the nominal diameter
of the bar.
7.4 The overall length of deformations shall be such that the gap (measured as a chord) between the ends of the deformations shall
not exceed 12.5 % 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 % 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 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 10 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 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 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 determinations on each lot (see Note 12) tested that typical deformation height,
gap, or spacing do not conform to the minimum requirements prescribed in Section 7. No rejection shall be made on the basis of
measurements if fewer than ten adjacent deformations on each side of the bar are measured.
A706/A706M − 22a
NOTE 2—As used within the intent of 8.3, the term “lot” shall mean all the bars of one bar size 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 requirements 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 tensile testing machine, where the
steel tested has a sharp-kneed or well-defined yield point.
9.2.2 Where the steel does not have a well-defined yield point, the yield strength shall be determined by the offset method (0.2 %
offset) as described in Test Methods and Definitions A370.
9.3 When material is furnished in coils, the test specimen shall be taken from the coil and straightened prior to placing it in the
jaws of the tensile testing machine. (See Note 23.)
NOTE 3—Straighten the test specimen to avoid formation of local sharp bends and to minimize cold work. Insufficient straightening prior to attaching the
extensometer can result in lower-than-actual yield strength readings.
9.3.1 Test specimens taken from post-fabricated material shall not be used to determine conformance to this specification. (See
Note 34.)
NOTE 4—Multiple bending distortion from mechanical straightening and fabricating machines can lead to excessive cold work, resulting in higher yield
strengths, lower elongation values, and a loss of deformation height.
9.4 The percentage of elongation shall be as prescribed in Table 2.
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.
The requirements for degree of bending and sizes of pins are prescribed in Table 3. When material is furnished in coils, the test
specimen shall 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 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 permissible to use other methods of bend testing as described in Test Methods E290, such as placing a specimen
across two round bearings free to rotate and applying the bending force with a fixed rounded-tip mandrel conforming to the
specified bend radius, allowing the bar to pass through with sufficient clearance. When failures occur under other methods of bend
resistance, retests shall be permitted under the bend-test method prescribed in 10.2.
11. Permissible Variation in Weight [Mass]
11.1 Deformed reinforcing bars shall be evaluated on the basis of nominal weight [mass]. The weight [mass] determined using
the measured weight [mass] of the test specimen and rounding in accordance with Practice E29, shall be at least 94 % of the
applicable weight [mass] per unit length prescribed in Table 1. In no case shall overweight [excess mass] of any deformed bar be
cause for rejection.
11.2 Weight [mass] variation for plain bars shall be computed on the basis of permissible variation in diameter. For plain bars
A706/A706M − 22a
3 1
smaller than ⁄8 in. [9.5 mm] in diameter, use Specification A510/A510M. For larger plain bars up to and including 2 ⁄2 in. [63.5
mm] in diameter, use Specification A6/A6M.
12. Finish
12.1 The bars shall be free of detrimental surface imperfections.
12.2 Rust, seams, su
...