1、Designation:A970/A970M09 Designation: A970/A970M 12Standard 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 revisio
2、n, 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.1. Scope*1.1This specification covers deformed and plain steel reinforcing bars in cut lengths, with a head attache
3、d to one or both ends,for concrete reinforcement. Attachment can be accomplished through welding, by integrally hot forging of a head from thereinforcing bar end, by internal threads in the head mating to threads on the bar end, or by a separate threaded nut to secure thehead to the bar. Heads are f
4、orge formed, machined from bar stock, or cut from plate.1.1 This specification covers deformed steel reinforcing bars in cut lengths, with a head attached to one or both ends, forconcrete reinforcement. Heads are forge-formed, machined from bar stock, or cut from plate. Attachment can be accomplishe
5、dthrough: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-swaging an externally threaded coupling sleeve onto the reinforcing bar;1.1.5 Cold-extruding an external coupling sleeve onto the
6、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 by means of the means of a ferrous-filler medium; or1.1.8 Separate threaded nut to secure the head to the bar.NOTE1This specifi
7、cation is applicable for headed bars produced with welded, threaded, or forged heads and used for reinforcement of concretestructures. The requirements of this specification are not applicable to headed bars where the attachment of the head is accomplished by alternate means.1.2Limitations on head d
8、imensions and on obstructions and interruptions of bar deformations on the non-planar features on thebearing face of the head are presented in 1The requirements of this specification are only applicable to headed bars where theattachment of the head is accomplished by one of the methods listed in 1.
9、1.1.2 Limitations on head dimensions 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
10、 for orders in either SIinch-pound units as Specification A970MA970 or inch-poundSI unitsshown in the text in brackets Specification A970. as Specification A970M.1.4 The values stated in either SIinch-pound units or inch-poundSI units are to be regarded separately as standard. Within thetext, the SI
11、 units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shallbe used independently of the other. Combining values from the two systems may result in non-conformance with the standard.specification.1.5 This standardspecification does not pur
12、port to address all of the safety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability ofregulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A370
13、 Test Methods and Definitions for Mechanical Testing of Steel ProductsA615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete ReinforcementA700 Practices for Packaging, Marking, and Loading Methods for Steel Products for ShipmentA706/A706M Specification for Low-Alloy Steel Def
14、ormed and Plain Bars for Concrete Reinforcement1This 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 Nov.Feb. 15, 2009.2012. Published December 2009.August 2012
15、. Originally approved in 1997. Last previous edition approved in 20072009 asA970/A970M 079. DOI: 10.1520/A0970_A0970M-0912.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM customer service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, r
16、efer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all
17、 changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 1
18、00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.2 AWS Standards:3AWS C6.1 Recommended Practices for Friction WeldingAWS D1.4/D1.4M Structural Welding Code - Reinforcing Steel2.3 U.S. Military Standard:4MIL-STD-129 Marking for Shipment and Storage2.4 U.S. Federal
19、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 forged headed barsteel bar used in the reinforcement of concrete that has the head(s) integrally forged to one or bothends.
20、 cold-extruded coupling sleeve headed bar(similar to cold-swaged threaded coupling 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 isaxially cold- extruded onto the bar end(s). This ex
21、truded coupling sleeve consists of an axially extruded sleeve portion that engagesthe deformed reinforcing bar and a pre-threaded integral stud with external threads, which match threads internal to the head(s).The head is screwed onto the mating threads on the extruded coupling sleeve. The threads
22、may be parallel or tapered.3.1.2 cold-swaged external sleeve headed bar(similar to cold-swaged threaded coupling 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
23、 bar end(s). This sleeve is a combination of a tubular sleeve portion extending in front of the head, and anintegral 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 th
24、e bar with multiple crimps from a hydraulic swaging tool and die,up to the face of the head section.3.1.3 cold-swaged 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
25、 by means of a sleeve that is cold-swaged onto thebar end(s). This sleeve is a one-piece unit with an integral cold-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
26、 coupling sleeve headed barsteel reinforcing bar used in the reinforcement of concrete that hasthe head(s) attached 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 t
27、ubular sleeve portion to the bar with multiple crimpsfrom a hydraulic swaging tool and die, up to the face of the 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 s
28、leeve. Thethreads may be parallel or tapered.3.1.5 ferrous-filler coupling sleeve headed barsteel reinforcing bar 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-f
29、iller material and the bar deformations. The ferrous-filler material is cast into the coupling sleeve. A variation 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 re
30、inforcing bar that has the head(s) integrally forged.3.1.7 headround, elliptical, or rectangular shape used to anchor a steel reinforcing bar in concrete.3.1.33.1.8 net bearing areagross cross-sectional area of the head minus the nominal cross-sectional area of the deformedreinforcing bar.3.1.43.1.9
31、 threaded headed barsteel reinforcing bar used in the reinforcement of concrete that has the head(s) attached to one orboth ends using tapered or straight threads internal to the head or by a separate internally threaded nut securing the head to thethreaded bar end.3.1.53.1.10 welded headed barsteel
32、 bar used in the reinforcement of concrete that has the head(s) welded to one or both ends.steel 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 ordered to thisspecifica
33、tion. Such requirements shall include but are not limited to the following:3Available from American Welding Society (AWS), 550 NW LeJeune Rd., Miami, FL 33126, http:/www.aws.org.4Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, At
34、tn: NPODS. Or visit: http:/assist.daps.dla.mil/online.5Available from American Concrete Institute (ACI), P.O. Box 9094, Farmington Hills, MI 48333-9094, http:/www.concrete.org.A970/A970M 1224.1.1 Quantity;4.1.2 Name of product: welded, forged, cold-swaged, cold-extruded, ferrous metal-filled sleeved
35、, or threaded headed bars forthe reinforcement of concrete;4.1.3 Reinforcing bar specification and year of issue;4.1.4 Bar size;4.1.5 Deformed or plain bars;4.1.6Head4.1.6 Head geometry, including thickness, diameter or height and width of the head;4.1.7 Head material specification and year of issue
36、 for welded head bars (5.2.1);4.1.8Bend testing of welded headed bars in sizes No. 36, 43, and 57 11, 14, and 18 (4.1.8 Bend testing of welded headed bars in sizes No. 11, 14, and 18 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 AST
37、M 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 BarsFor welded headed bars, the reinforcing bars shall conform to Specification A706/A706M. For forgedheaded bars or thr
38、eadednon-welded headed bars, the reinforcing bars shall conform to Specification A615/A615M orA706/A706M, as specified by the purchaser.5.2 Heads:5.2.1 For welded and threaded headed bars, the head material shall be selected by the manufacturer. The head material shall beselected by the manufacturer
39、.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 pur
40、chaser. 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 the
41、 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).5.3.1Head dimensions shall define the head geometry including thickness, diameter or height and width
42、of the head (Fig. 1).5.4 When specified by the purchaser in the purchase order or contract as a class HA headed bar, head dimensions shall meetthe requirements of Annex A1.NOTE3The requirements for head dimensions in 3Some methods of attachment, as defined in Section 3 of this specification, do not
43、meet therequirements on obstructions as prescribed in Annex A1are mandated by certain consensus building codes and design standards, for example, 9BuildingCode Requirements for Structural Concrete (ACI 318).9 . The requirements for head dimensions, limitations to reinforcing bar deformation interrup
44、tionsand the size of obstruction allowances provided in Annex A1 are mandated by certain consensus building codes and design standards, for example,9Building Code Requirements for Structural Concrete (ACI 318).9 Heads with obstructions that do not conform to Annex A1 may not be permitted foruse by c
45、ertain building codes and design standards, such as 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/QCproce
46、dures.FIG. 1 Headed Reinforcing BarA970/A970M 1235.6 ForgingFor 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, o
47、r it shall be heldon the bar end by a nut and counternut. Thread specifications and standards shall be selected by the manufacturer unless otherwiseagreed with the purchaser. manufacturer.5.7.2 The out-of-roundness in the as-rolled reinforcing bar shall be evaluated so that the manufacturers minimum
48、 threaddimensions are maintained.5.7.3 It shall be permissible to hot- 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 producti
49、on method and product quality prior to manufacture.Mechanical testing 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. FailureThe failure mode shall be reported as partial or total fracture of the bar, the head, or thehead-to-bar connection.6.2.2 Specimen PreparationTensile test specimens shall be the full cross-section of the bar with a head attached to one en
