1、Designation: A767/A767M 09 (Reapproved 2015)A767/A767M 16Standard Specification forZinc-Coated (Galvanized) Steel Bars for ConcreteReinforcement1This standard is issued under the fixed designation A767/A767M; the number immediately following the designation indicates the yearof original adoption or,
2、 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. Sco
3、pe Scope*1.1 This specification covers steel reinforcing bars with protective zinc coatings applied by dippingimmersing the properlyprepared reinforcing bars into a molten bath of zinc.NOTE 1The galvanizer is identified throughout this specification as the manufacturer.1.2 Guidelines for constructio
4、n practices at the job-site are presented in Appendix X1.1.3 Guidelines for use of zinc-coated (galvanized) reinforcing bars with non-galvanized steel forms are presented in AppendixX2.1.4 The text of this specification references notes and footnotes which provide explanatory material. These notes a
5、nd footnotes(excluding those in tables) shall not be considered as requirements of the specification.1.5 This specification is applicable for orders in either inch-pound units (as Specification A767) or SI units (as SpecificationA767M).1.6 The values stated in either SI or inch-pound units or SI uni
6、ts are to be regarded separately as standard. Within the text, theinch-poundSI units are shown in brackets. The values stated in each system aremay not be exact equivalents. Therefore, eachsystem mustshall be used independently of the other. Combining values from the two systems may result in noncon
7、formancenon-conformance with this specification.2. Referenced Documents2.1 ASTM Standards:2A90/A90M Test Method for Weight Mass of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy CoatingsA615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete ReinforcementA706/A706M
8、 Specification for Deformed and Plain Low-Alloy Steel Bars for Concrete ReinforcementA780/A780M Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized CoatingsA996/A996M Specification for Rail-Steel and Axle-Steel Deformed Bars for Concrete ReinforcementB6 Specification for ZincB487
9、 Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross SectionE376 Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Testing Methods2.2 ACI Specification:Standard:3ACI 301 Specifications for Structural Concre
10、te2.3 AWS Standard:4AWS D1.4D1.4M Structural Welding CodeReinforcing Steel1 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.05on Steel Reinforcement.Current edition approved Nov. 15, 20
11、15Sept. 1, 2016. Published November 2015September 2016. Originally approved in 1979. Last previous edition approved in20092015 as A767/A767M 09.A767/A767M 09 (2015). DOI: 10.1520/A0767_A0767M-09R15.10.1520/A0767_A0767M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contac
12、tASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American Concrete Institute (ACI), P.O. Box 9094, Farmington Hills, MI 48333-9094, http:/www.concrete.org.4 Available from
13、 American Welding Society (AWS), 8669 NW 36 St., #130, Miami, FL 33166-6672, http:/www.aws.org.This 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 pos
14、sible 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 ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCo
15、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Definition of Term Specific to This Specification:3.1.1 lot, nall bars of one size furnished to the same steel reinforcing bar specification that have been coated within
16、a singleproduction shift.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specify all requirements that are necessary for material ordered to thisspecification. Such requirements shall include, but are not limited to, the following: Orders for zinc-coated (galvanized) ba
17、rs forconcrete reinforcement under this specification shall include the following information:3.1.1 Quantity of bars,3.1.2 Size of bars,4.1.1 Reinforcing bar specification Specification for reinforcing bars to be coated (ASTM designation and year of issue) and(5.1grade, ),4.1.2 Quantity of bars,4.1.
18、3 Size and grade of bars,4.1.4 Class of coating, coating (Class 1 or Class 2) (6.5),4.1.5 GalvanizationGalvanizing before or after fabrication, and fabrication for Class 1 coating (7.3),NOTE 1A typical ordering description is as follows: Deformed Grade 420 bars to ASTM A615M-_; 1600 m, No. 19, 8 m l
19、ong in secured lifts;zinc-coated (galvanized) to ASTM A767M-_; including Class 1 coating, and galvanization after fabrication.Deformed Grade 60 bars to ASTM A615-_; 4000 linear ft, No. 6, 20 ft, 0 in. long in secured lifts; zinc-coated (galvanized) to ASTM A767-_,including Class 1 coating, and galva
20、nization after fabrication.4.1.6 ASTM designation A767 A767M 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 (8.1),4.2.2 Manufacturer certification (10.1), and4.2.3 Other speci
21、al requirements, if any.5. Materials5.1 Steel reinforcing bars to be zinc-coated (galvanized) shall conform to one of the following Specifications: A615, A706, orA996 A615M, A706M, or A996M, as specified by the purchaser.5.2 The zinc used for coating shall be any grade that conforms to Specification
22、 B6.6. Galvanizing Zinc Coating Process6.1 Reinforcing bars shall be prepared for galvanizing using any surface cleaning process that allows the zinc to bond with thesteel, such that the galvanized bar coating appearance and continuity requirements in Section 7 of this specification are satisfied.6.
23、2 The reinforcing bars shall be coated by immersing the reinforcing bars into a molten bath of zinc until the zinc reacts withthe steel surface to form zinc-iron inter-metallic alloys.6.3 Handling: After solidification of the zinc coating, the coated reinforcing bars shall meet the minimum coating t
24、hickness orequivalent weight mass requirements in Table 1.4.1.1 The galvanizer shall be permitted to subject the newly coated steel reinforcing bars to air or steam wiping to removeexcess zinc from the bars. After the wiping, the coated steel reinforcing bars shall meet the minimum coating mass weig
25、ht.NOTE 2During the wiping process, care should be taken to maintain a uniformly thick coating around the perimeter of the bar.NOTE 2Excess liquid zinc can be removed from freshly coated bars either by allowing liquid zinc to drain off the surface by gravity, or by subjectingthe bars to an air or wi
26、ping process, where in the case of the latter method, care should be taken to maintain a uniformly thick coating around the perimeterof the bar.4.1.2 It shall be the responsibility of the galvanizer to maintain identity of the reinforcing bars throughout the galvanizingprocess and to the point of sh
27、ipment.6.4 It shall be the responsibility of the galvanizer to maintain identity of the reinforcing bars throughout the galvanizing processand to the point of shipment.6.5 Class of Coating Thickness and Equivalent Weight Mass:6.5.1 This specification includes two classes of zinc coating thickness an
28、d corresponding equivalent weight mass. Theequivalent weight mass of zinc coating on the bar shall conform to the requirements in Table 1.6.6 Mass Weight of Coating and Test:Coating Thickness Tests:4.2.1 This specification includes two classes of coating mass weight. The mass weight of zinc coating
29、based on actual areaof the bar shall conform to the requirements shown in Table 1.A767/A767M 162NOTE 3The nominal diameter of a deformed bar is equivalent to that of a plain round bar having the same mass per metre weight per foot as thedeformed bar. Coating mass weight shown in is based on an assum
30、ed area ratio of 1.2:1 (actual to nominal surface area of the steel reinforcing bar).6.6.1 Magnetic Thickness MeasurementsThe mass weight of the coating shall be determined by magnetic thickness gagemeasurements Coating thickness tests shall be performed in accordance with Practiceone E376. The thic
31、kness measurement is usedto calculate the mass weight by multiplying it by the surface area of coated bar and by the zinc density. One or more of thefollowing methods shall be permitted to be used to referee the results obtained by magnetic thickness measurements.of thefollowing test methods:6.6.1.1
32、 Magnetic Thickness Gauge MeasurementsThe thickness of the coating shall be determined by magnetic thicknessgauge measurements in accordance with Practice E376. Use Table 1 to determine the equivalent weight mass of the coating. Oneor more of the following methods shall be permitted to be used to re
33、feree the results obtained by magnetic thickness gaugemeasurements.6.6.1.2 Stripping MethodThe mass weightweight mass shall be determined by stripping the coating from the steelreinforcing bar section in accordance with Test Method A90/A90M. This test method shall not be used for deformed reinforcin
34、gbars.NOTE 4This is a destructive test appropriate for small samples of a minimum of 2000 mm2 3 in.2 of surface area. It does note include the massweight of iron reacted with the zinc coating and may overestimate coating mass weight by up to 10 %.6.6.1.3 Weighing Before and After GalvanizingThe mass
35、 weightweight mass shall be determined by weighing steelreinforcing bars before and after galvanizing. The difference between the two measurements divided by the surface area of the barsprovides the mass weight. weight mass/unit area. The original weighing shall occur after pickling and drying. The
36、secondweighing shall occur after cooling to ambient temperature. This test method shall not be used for deformed reinforcing bars.NOTE 3Due to variations in the surface areas of deformed bars as a function of deformation pattern and bar size, the methods in 6.6.1.2 and 6.6.1.3to measure coating thic
37、kness are not appropriate for deformed bars. These are destructive tests appropriate for small samples of a minimum of 3 in.2 2000mm2 of surface area. These tests do not include the weight mass of iron reacted with the zinc coating and may overestimate coating weight massby up to 10 %.6.6.1.4 Micros
38、copyThe mass weight equivalent weight mass shall be determined by cross-sectional and opticalmeasurement in accordance with Test Method B487. A cross-section sample of the steel shall be polished and examined with anoptical microscope to determine the coating thickness. The coating mass weight shall
39、 be determined by multiplying coatingthickness by Measurements of thickness shall not be taken on points located on longitudinal ribs or transverse deformations. UseTable 1the surface area of the coated sample and by the density of zinc. to determine the equivalent weight mass of the coating.6.6.2 N
40、umber of TestsFor determination of the coating mass weight, three random samples shall be tested from each lot. Foreach magnetic thickness measurement sample, five or more The following number of coated steel samples and measurements shallbe made at various points throughout the sample so as to repr
41、esent the entire surface of the sample. A total of at least fifteenmeasurements shall be averaged to obtain the coating thickness. For the microscopy method, five samples shall be tested per lot.Each sample shall be measured on four sides and the total of twenty measurements shall be averaged to obt
42、ain the coatingthickness. For the stripping method and the weighing method, three samples per lot shall be measured. to determine coatingthickness:NOTE 5Alot shall be as follows:All bars of one size furnished to the same steel reinforcing bar specification that have been galvanized within a singlepr
43、oduction shift.TABLE 1 Mass Weight of Zinc CoatingCoating ClassMass Weight of Zinc Coating,min, g/m2 ozft2 of SurfaceClass IBar Designation Size No. 10 3 915 3.00Bar Designation Size No. 13 4 and Larger 1070 3.50Class IIBar Designation Size No. 10 3 and Larger 610 2.00TABLE 1 Zinc Coating Thickness
44、and Equivalent Weight MassNOTE 1The key value in this table is micrometres (m) and is based on a zinc density of 7140 kg/m3. The other values are based on conventionsusing the following formulae: mils = m 0.03937; oz/ft2 = m 0.0232; g/m2 = m 7.14; and mg/cm2 = m 0.714.ClassificationZinc Thickness We
45、ight Mass/Unit Areamils m oz/ft2 mg/cm2Class 1Bar Designation No. 3 10 5.1 129 3.0 92Bar Designation No. 4 13 and Larger 5.9 150 3.5 107Class 2Bar Designation No. 3 10 and Larger 3.4 86 2.0 62A767/A767M 1636.6.2.1 For determination of the coating weight mass using magnetic thickness gauge measuremen
46、ts, three random samplesshall be tested from each lot. For each magnetic thickness gauge measurement sample, five or more measurements shall be madeat various points throughout the sample so as to represent the entire surface of the sample. A total of at least fifteen measurementsshall be averaged t
47、o obtain the coating thickness.6.6.2.2 For determination of the coating thickness or equivalent weight mass using the stripping method and the weighingmethod, three random coated steel samples shall be tested from each lot.6.6.2.3 For determination of the coating thickness or equivalent weight mass
48、using the microscopy method, five randomcoated steel samples shall be tested per lot. Each sample shall be measured on four sides and the total of twenty measurementsshall be averaged to obtain the coating thickness.4.2.4 RetestsIf the average zinc coating mass weight fails to meet the requirements
49、of Table 1, six additional randomsamples from the lot shall be permitted to be tested. If the average zinc coating mass weight of the six samples conforms to therequirements of Table 1, the lot shall be accepted.6.7 RetestsIf the average zinc coating thickness or equivalent weight mass fails to meet the requirements of Table 1, sixadditional random samples from the lot shall be permitted to be tested. If the average zinc c
