1、Designation: A970/A970M 12A970/A970M 13Standard Specification forHeaded Steel Bars for Concrete Reinforcement1This standard is issued under the fixed designation A970/A970M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year
2、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.1. Scope*1.1 This specification covers deformed steel reinforcing bars in cut lengths, with a head attached to one or both ends
3、, forconcrete reinforcement. Heads are forge-formed, machined from bar stock, or cut from plate. Attachment can be accomplishedthrough:1.1.1 Welding;1.1.2 Integrally hot forging of a head from the reinforcing bar end;1.1.3 Internal threads in the head mating to threads on the bar end;1.1.4 Cold-swag
4、ing an externally threaded coupling sleeve onto the reinforcing bar;1.1.5 Cold-extruding an external coupling sleeve onto the reinforcing bar;1.1.6 Cold-swaging an external coupling sleeve or headed sleeve onto the reinforcing bar;1.1.7 Attaching a coupling sleeve to the end of the reinforcing bar b
5、y means of the means of a ferrous-filler medium; or1.1.8 Separate threaded nut to secure the head to the bar.NOTE 1The requirements of this specification are only applicable to headed bars where the attachment of the head is accomplished by one of themethods listed in 1.1.1.2 Limitations on head dim
6、ensions and on obstructions and interruptions of bar deformations on the non-planar features on thebearing face of the head are presented in Annex A1. The requirements in Annex A1 only apply when specified by the purchaser(see 4.1.13).1.3 This specification is applicable for orders in either inch-po
7、und units as Specification A970 or SI units as SpecificationA970M.1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI unitsare shown in brackets. The values stated in each system may not be exact equivalents; therefore, each
8、 system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with the specification.1.5 This specification does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this stan
9、dard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testing of Steel ProductsA615/A615M Specification for Deformed and Plain Carbon-
10、Steel Bars for Concrete ReinforcementA700 Practices for Packaging, Marking, and Loading Methods for Steel Products for ShipmentA706/A706M Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement2.2 AWS Standards:3AWS C6.1 Recommended Practices for Friction WeldingAWS D1.4
11、/D1.4M Structural Welding Code - Reinforcing Steel1 This specification is under the jurisdiction of ASTM A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of A01.05 on Steel Reinforcement.Current edition approved Feb. 15, 2012April 1, 2013. Published August 2012May 20
12、13. Originally approved in 1997. Last previous edition approved in 20092012 asA970/A970M 09.A970/A970M 12. DOI: 10.1520/A0970_A0970M-12. 10.1520/A0970_A0970M-13.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM customer service at serviceastm.org. For Annual Book
13、 of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American Welding Society (AWS), 550 NW LeJeune Rd., Miami, FL 33126, http:/www.aws.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM sta
14、ndard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by AS
15、TM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.3 U.S. Military Standard:4MIL-STD-129 Marking for Shipment and Storage2.4
16、U.S. Federal Standard:4Fed. Std. No. 123 Marking for Shipment (Civil Agencies)2.5 ACI Standard:5ACI 318 Building Code Requirements for Structural Concrete3. Terminology3.1 Definitions:3.1.1 cold-extruded coupling sleeve headed bar(similar to cold-swaged threaded coupling sleeve headed bar); steelrei
17、nforcing bar used in the reinforcement of concrete that has the head(s) attached to one or both ends by means of a couplingsleeve that is axially cold- extruded onto the bar end(s).This extruded coupling sleeve consists of an axially extruded sleeve portionthat engages the deformed reinforcing bar a
18、nd a pre-threaded integral stud with external threads, which match threads internal tothe head(s). The head is screwed onto the mating threads on the extruded coupling sleeve. The threads may be parallel or tapered.3.1.2 cold-swaged external sleeve headed bar(similar to cold-swaged threaded coupling
19、 sleeve headed bar); steel reinforcingbar used in the reinforcement of concrete that has the head(s) attached to one or both ends by means of a coupling sleeve that iscold- swaged onto the bar end(s). This sleeve is a combination of a tubular sleeve portion extending in front of the head, and aninte
20、gral one-piece head immediately adjacent to the cold-swaged sleeve. The sleeve and head assembly is attached to the deformedreinforcing bar by cold-swaging the tubular sleeve portion to the bar with multiple crimps from a hydraulic swaging tool and die,up to the face of the head section.3.1.3 cold-s
21、waged headed sleeve headed bar(similar to cold-swaged external coupling sleeve headed bar); steel bar used inthe reinforcement of concrete that has the head(s) attached to one or both ends by means of a sleeve that is cold-swaged onto thebar end(s). This sleeve is a one-piece unit with an integral c
22、old-swaged head. The head assembly is attached to the deformedreinforcing bar by cold-swaging the tubular sleeve to the bar with a hydraulic swaging tool and die.3.1.4 cold-swaged threaded coupling sleeve headed barsteel reinforcing bar used in the reinforcement of concrete that has thehead(s) attac
23、hed to one or both ends by means of a coupling sleeve that is cold-swaged onto the bar end(s). The coupling sleeveassembly is attached to the deformed reinforcing bar by cold-swaging the tubular sleeve portion to the bar with multiple crimpsfrom a hydraulic swaging tool and die, up to the face of th
24、e prethreaded section. This coupling sleeve is pre-threaded with externalthreads, which match threads internal to the head(s). The head is screwed onto the mating threads on the coupling sleeve. Thethreads may be parallel or tapered.3.1.5 ferrous-filler coupling sleeve headed barsteel reinforcing ba
25、r used in the reinforcement of concrete that has the head(s)attached to one or both ends by means of a coupling sleeve mechanically attached to the bar by means of an interlock offerrous-filler material and the bar deformations. The ferrous-filler material is cast into the coupling sleeve. A variati
26、on includes aseparate internally threaded nut secured to the threaded bar end or attached by means of welding a plate to the end of a preparedcoupling sleeve3.1.6 forged headed barsteel reinforcing bar that has the head(s) integrally forged.3.1.7 headround, elliptical, or rectangular shape used to a
27、nchor a steel reinforcing bar in concrete.3.1.8 net bearing areagross cross-sectional area of the head minus the nominal cross-sectional area of the deformedreinforcing bar.3.1.9 threaded headed barsteel reinforcing bar that has the head(s) attached using tapered or straight threads internal to theh
28、ead or by a separate internally threaded nut securing the head to the threaded bar end.3.1.10 welded headed barsteel reinforcing bar that has the head(s) welded.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specify all requirements that are necessary for material orde
29、red to thisspecification. Such requirements shall include but are not limited to the following:4.1.1 Quantity;4.1.2 Name of product: welded, forged, cold-swaged, cold-extruded, ferrous metal-filled sleeved, or threaded headed bars forthe reinforcement of concrete;4.1.3 Reinforcing bar specification
30、and year of issue;4.1.4 Bar size;4.1.5 Deformed bars;4 Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. Or visit: http:/assist.daps.dla.mil/online.5 Available from American Concrete Institute (ACI), P.O. Box 9094, Far
31、mington Hills, MI 48333-9094, http:/www.concrete.org.A970/A970M 1324.1.6 Head geometry, including thickness, diameter or height and width of the head;4.1.7 Head material specification and year of issue for welded head bars (5.2.1);4.1.8 Bend testing of welded headed bars in sizes No. 11, 14, and 18
32、36, 43, and 57 (6.4.1);4.1.9 Number of heads per bar length;4.1.10 Length of bar assembly;4.1.11 Packaging;4.1.12 ASTM designation and year of issue; and4.1.13 Optional requirements of Annex A1, if applicable.4.1.14 Optional copy of material test report.5. Material and Manufacture5.1 Reinforcing Bar
33、sFor welded headed bars, the reinforcing bars shall conform to Specification A706/A706M. For forgednon-welded headed bars, the reinforcing bars shall conform to Specification A615/A615M or A706/A706M, as specified by thepurchaser.5.2 Heads:5.2.1 The head material shall be selected by the manufacture
34、r.5.3 The head dimensions shall be provided by the purchaser in the order. Head dimensions shall define the head geometryincluding thickness, diameter, or height and width of the head (Fig. 1). Alternate head dimensions supplied by the manufacturershall be permitted if agreed to in advance by the pu
35、rchaser. The manufacturer shall furnish documentation to the purchaser, in theform of calculations or test reports, or both, that confirms the suitability of alternate head dimensions for the intended application.NOTE 2Alternate head dimensions resulting in a net bearing area less than four times th
36、e nominal cross-sectional area of the deformed reinforcingbar are not suitable for use in construction projects governed by certain consensus building codes and design standards (see 5.4 and Note 3).5.4 When specified by the purchaser in the purchase order or contract as a class HA headed bar, head
37、dimensions shall meetthe requirements of Annex A1.NOTE 3Some methods of attachment, as defined in Section 3 of this specification, do not meet the requirements on obstructions as prescribed inAnnexA1. The requirements for head dimensions, limitations to reinforcing bar deformation interruptions and
38、the size of obstruction allowances providedin AnnexA1 are mandated by certain consensus building codes and design standards, for example, “Building Code Requirements for Structural Concrete(ACI 318).“ Heads with obstructions that do not conform to AnnexA1 may not be permitted for use by certain buil
39、ding codes and design standards, suchas ACI 318.5.5 WeldingA welding procedure conforming to AWS D1.4/D1.4M shall be used for all required production welding of thehead to the bar, except for friction welding that shall conform to AWS C6.1 in conjunction with the manufacturers QA/QCprocedures.5.6 Fo
40、rgingFor integrally forged headed bars, the heads shall be produced by deforming the bar ends in a hot-forging process.5.7 Threading:5.7.1 Threads on bars shall be either tapered or straight. The head shall either thread onto the bar directly, or it shall be heldon the bar end by a nut and counternu
41、t. Thread specifications and standards shall be selected by the manufacturer.5.7.2 The out-of-roundness in the as-rolled reinforcing bar shall be evaluated so that the manufacturers minimum threaddimensions are maintained.FIG. 1 Headed Reinforcing BarA970/A970M 1335.7.3 It shall be permissible to ho
42、t- or cold-roll, or machine cut, threads into the surface of the bar and heads at the option ofthe manufacturer.6. Mechanical Test and Performance Requirements6.1 Headed bars shall be subjected to mechanical tests to verify production method and product quality prior to manufacture.Mechanical testin
43、g also shall be performed at intervals during production of the assembly.6.2 Tensile Tests:6.2.1 Tensile testing of the headed bar assembly shall be performed in accordance with the requirements described in TestMethods and Definitions A370. The failure mode shall be reported as partial or total fra
44、cture of the bar, the head, or the head-to-barconnection.6.2.2 Specimen PreparationTensile test specimens shall be the full cross-section of the bar with a head attached to one endof the reinforcing bar. The minimum length of the test specimen shall be the greater of 10 in. 250 mm or ten times the n
45、ominaldiameter of the bar. The test specimen shall be placed in the testing machine with the head supported to prevent movement andbending of the head. Provisions shall be made for clearance between the support and any weld or forming material on thereinforcing bar-to-head connection. The opposite b
46、ar end of the bar, without a head attached, shall be gripped by the testingmachine and loaded to failure.6.3 Tensile Requirements:6.3.1 Tensile PropertiesThe tensile properties of the test specimen shall conform to one of the following classes:6.3.1.1 Class ADevelop the minimum specified tensile str
47、ength of the reinforcing bar.6.3.1.2 Class BDevelop the minimum specified tensile strength and the minimum specified elongation of the reinforcing bar.NOTE 4Reference the requirements of Specifications A615/A615M and A706/A706M for minimum reinforcing bar tensile properties. Class A hasbeen introduc
48、ed for applications that require the development of the minimum tensile strength of the reinforcing bar. The Class B criteria requires thehead and the head-to-bar connection to meet or exceed the minimum specified tensile strength and the minimum specified elongation requirements ofthe reinforcing b
49、ar. In the previous criteria, the failure of the head or the head-to-bar connection within the attachment region was cause for rejection.6.4 Bend Test Requirements:6.4.1 Only welded headed bars in sizes No. 3 to 10 10 to 32 shall be subject to bend testing. Bend testing of welded headedbars in sizes No. 11, 14, and 18 36, 43, and 57 shall be subject to agreement between the purchaser and manufacturer.NOTE 5Serious safety issues may be involved in performing bend tests on welded headed bars in sizes No. 11, 14, and 18 36, 43, and 57. Thus,6.
