1、Designation: A934/A934M 07A934/A934M 13Standard Specification forEpoxy-Coated Prefabricated Steel Reinforcing Bars1This standard is issued under the fixed designation A934/A934M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the
2、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*1.1 This specification covers deformed and plain steel reinforcing bars which prior to surface preparation are pr
3、efabricated andthen coated with a protective fusion-bonded epoxy coating by electrostatic spray or other suitable method.1.2 Prefabricated steel reinforcing bars coated with fusion-bonded epoxy formulations powder coating in accordance with thisspecification are not intended to be bent or rebent.fab
4、ricated before being coated.NOTE 1Experience has shown epoxy-coated prefabricated steel reinforcing bars have limited capability to be successfully field bent or rebent (see9.3.1). If the construction project requires epoxy-coated steel reinforcing bars that must be able to sustain field bending or
5、rebending, the use of coatedbars conforming to Specification A775/A775M should be considered.1.3 Organic coatings other than epoxy may be used provided they meet the requirements of this specification.1.4 Requirements for epoxy coatings are contained in Annex A1.1.5 Guidelines for application proces
6、s and product test procedures of epoxy coatings for steel reinforcing bars are presented inAppendix X1.1.6 Guidelines for construction practices at the job-site for coated steel reinforcing bars are presented in Appendix X2.1.7 This specification is applicable for orders in either SI (metric) units
7、as Specification A934M) or inch-pound units asSpecification A934.1.8 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Com
8、bining values from thetwo systems may result in non-conformance with the standard.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and d
9、etermine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete ReinforcementA706/A706M Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete ReinforcementA775/
10、A775M Specification for Epoxy-Coated Steel Reinforcing BarsA944 Test Method for Comparing Bond Strength of Steel Reinforcing Bars to Concrete Using Beam-End SpecimensA996/A996M Specification for Rail-Steel and Axle-Steel Deformed Bars for Concrete ReinforcementB117 Practice for Operating Salt Spray
11、Fog) ApparatusD4060 Test Method for Abrasion Resistance of Organic Coatings by the Taber AbraserG8 Test Methods for Cathodic Disbonding of Pipeline CoatingsG14 Test Method for Impact Resistance of Pipeline Coatings (Falling Weight Test)G20 Test Method for Chemical Resistance of Pipeline CoatingsG42
12、 Test Method for Cathodic Disbonding of Pipeline Coatings Subjected to Elevated TemperaturesG62 Test Methods for Holiday Detection in Pipeline Coatings1 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of S
13、ubcommittee A01.05on Steel Reinforcement.Current edition approved Sept. 1, 2007June 1, 2013. Published October 2007June 2013. Originally approved in 1995. Last previous edition approved in 20042007 asA934/A934M04. DOI: 10.1520/A0934_A0934M-07. 07. DOI: 10.1520/A0934_A0934M-13.2 For referencedASTM st
14、andards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an
15、 ASTM standard 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 publis
16、hed by ASTM 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 States12.2 NACE International Standard:3RP 0287 Field Measurement of Surfa
17、ce Profile of Abrasive Blast Cleaned Steel Surfaces Using a Replica Tape2.3 Society for Protective Coatings Specifications:4SSPC-SP 10 Near-White Blast CleaningSSPC-VIS 1 Pictorial Surface Preparation Standards for Painting Steel SurfacesSSPC-PA 2 Measurement of Dry Coating Thickness with Magnetic G
18、ages2.4 American Concrete Institute Specifications:5ACI 301 Specifications for Structural ConcreteACI 315 Details and Detailing of Concrete Reinforcement2.5 Concrete Reinforcing Steel Institute:6Voluntary Certification Program for Fusion-Bonded Epoxy Coating Applicator Plants3. Terminology3.1 Defini
19、tions of Terms Specific to This Standard:3.1.1 conversion coatingpreparation of the blast-cleaned metal surface prior to coating application that is designed to pretreatthe metal to promote coating adhesion, reduce metal coating reactions, improve corrosion resistance, and increase blisterresistance
20、3.1.2 disbondingloss of adhesion between the fusion-bonded epoxy coating and the steel reinforcing bar.3.1.3 fusion-bonded epoxy coatingproduct containing pigments, thermosetting epoxy resins, crosslinking agents, and otheradditives, which is applied in the form of a powder onto a clean, heated met
21、allic substrate and fuses to form a continuous barriercoating.3.1.4 holidaydiscontinuity in a coating that is not discernible to a person with normal or corrected vision.3.1.5 patching materialliquid two-part epoxy coating used to repair damaged areas.3.1.6 prefabricated barssteel reinforcing bars t
22、hat are cut to specified lengths and bent to the required shapes prior to coating.3.1.7 wetting agentmaterial that lowers the surface tension of water allowing it to penetrate more effectively into smalldiscontinuities in the coating, giving a more accurate indication of the holiday count.4. Orderin
23、g Information4.1 It shall be the responsibility of the purchaser to specify all requirements that are necessary for the coated steel reinforcingbars under this specification. Such requirements to be considered include, but are not limited to, the following:4.1.1 Reinforcing bar specification and yea
24、r of issue,4.1.2 Quantity and bend types of bars,4.1.3 Size and grade of bars,4.1.4 Requirements for the powder coating and provision of test data (5.2),4.1.5 Requirements for patching material (5.3),4.1.6 Quantity of patching material,4.1.7 Coated specimens shall be provided by the manufacturer out
25、 of the same production lot of coated reinforcement beingfurnished to the purchaser (13.1).4.1.8 Whether a report on tests performed on the coated steel reinforcing bars being furnished is required (15.1),4.1.9 Method for temperature reduction of hot, freshly coated bars (unforced air cool down or f
26、orced air/water quench) (8.3).NOTE 1A typical ordering description is as follows: Deformed Grade 420 bars to ASTM A615M _; 6000 m, No. 19; cut to specified lengthsand fabricated prior to coating; epoxy-coated to ASTM A934M _; including written certifications for the powder coating and coated bars an
27、d 1 Lof patching material.Deformed Grade 60 bars toASTM A615M _; 20 000 ft, No. 6; cut to specified lengths and fabricated prior to coating; epoxy-coated toASTMA934 _; including written certifications for the powder coating and coated bars and 1 qt. of patching material.5. Materials5.1 Steel reinfor
28、cing bars to be coated shall meet the requirements of one of the following specifications: A615M, A706M, orA996M A615, A706, or A996 as specified by the purchaser and shall be free of contaminants such as oil, grease, or paint.NOTE 2Prior to coating, the steel reinforcing bars should be inspected fo
29、r their suitability for coating. Bars with sharp edges on the deformations,rolled-in slivers, or other surface imperfections are difficult to coat properly. The coating will flow away from the sharp edges and may result in inadequatecoating thickness at these points.3 Available from NACE Internation
30、al, 1440 South Creek Dr., Houston, TX 770844906.4 Available from The Society for Protective Coatings, 40 24th St., Pittsburgh, PA 152224656.5 Available from American Concrete Institute, 38800 Country Club Dr., Farmington Hills, MI 48331.6 Available from Concrete Reinforcing Steel Institute, 933 N. P
31、lum Grove Rd., Schaumburg, IL 601734758.A934/A934M 1325.2 The powder coating shall meet the requirements of Annex A1. Upon request, the purchaser shall be provided with test datafor review.5.2.1 Awritten certification shall be furnished to the purchaser that properly identifies the lot designation o
32、f the powder coatingused in the order, material quantity represented, date of manufacture, name and address of the powder coating manufacturer, anda statement that the supplied powder coating is the same composition as that qualified according to AnnexA1 of this specification.The powder coating shal
33、l be used within the powder coating manufacturers written recommended shelf life.5.2.2 If specified in the order, a representative 0.2-kg 8-oz sample of the powder coating shall be supplied to the purchaserfrom each batch. The sample shall be packaged in an airtight container and identified by the b
34、atch designation.5.2.3 The powder coating shall be maintained in a temperature-controlled environment following the written recommendationsof the powder coating manufacturer until ready for use, at which point the powder coating shall be given sufficient time to reachapproximate plant ambient temper
35、ature.5.3 If specified in the order, patching material, compatible with the coating, inert in concrete, and recommended by the powdercoating manufacturer, shall be supplied to the purchaser.6. Prefabrication of Steel Reinforcing Bars6.1 The steel reinforcing bars to be coated shall have been prefabr
36、icated in accordance with the purchasers requirements orproject specifications prior to surface preparation.NOTE 3Drive rolls on shear beds and backup barrels on benders should be protected with a suitable covering to minimize crushing or creating rolloverdamage to the steel reinforcing bar deformat
37、ions during the fabrication process.7. Surface Preparation of Steel Reinforcing Bars7.1 The surface of the steel reinforcing bars shall be cleaned by abrasive blast steel grit to near-white metal in accordance withSSPC-SP 10.7.1.1 The final surface condition shall be defined according to SSPC-VIS 1.
38、7.1.2 Average blast profile roughness depth readings of 37 to 100 m 1.5 to 4.0 mils, as determined by replica tapemeasurements using RP 0287 or other methods acceptable to the purchaser, shall be considered suitable as an anchor pattern.NOTE 4The use of a profilometer type surface measurement instru
39、ment that measures the peak count as well as the maximum profile depth isrecommended.7.2 A steel grit of Rockwell Hardness C50 or higher shall be used. A maximum of 5 % steel shot is allowable in the media.NOTE 5Recycled steel grit abrasive should be maintained so as to minimize contaminants such as
40、 oil, salt, and dust caused by the blasting operation.7.3 Multidirectional, high-pressure dry air knives shall be used after blast cleaning to remove dust, grit, and other foreign matterfrom the steel surface. The air knives shall not deposit oil on the steel reinforcing bars.NOTE 6It is recommended
41、 that incoming steel reinforcing bars and blast media be checked for salt contamination prior to use. Blast media foundto be salt contaminated should be rejected. Steel reinforcing bars found to be salt contaminated from exposure to deicing salts or salt spray should becleaned by acid washing or oth
42、er suitable methods to remove salt contaminants from the surface prior to blast cleaning.7.4 It shall be permissible for the manufacturer to use a chemical wash or conversion of the steel reinforcing bar surface, or both,to enhance coating adhesion. This pretreatment shall be applied after abrasive
43、cleaning and before coating, in accordance with thewritten application instructions specified by the pretreatment manufacturer.8. Coating Application8.1 Cleaned, uncoated steel reinforcing bars shall be handled by personnel wearing clean gloves to prevent contamination ofthe steel surface.8.2 If pre
44、treatment is used in the preparation of the surface the powder coating shall be applied to the cleaned and pretreatedsteel reinforcing bar surface as soon as possible after surface treatments have been completed, and before visible oxidation of thesurface occurs as discernible to a person with norma
45、l or corrected vision. In no case shall application of the coating be delayedmore than 3 h after cleaning.8.3 The fusion-bonded epoxy powder coating shall be applied in accordance with the written recommendations of themanufacturer of the powder coating for initial steel surface temperature range an
46、d post application cure requirements. Thetemperature of the surface immediately prior to coating shall be measured using infrared guns or temperature-indicating crayonsat least once every 30 min during continuous operations.NOTE 7The use of infrared and temperature-indicating crayon measurement of t
47、he steel reinforcing bars is recommended.8.4 The powder coating shall be applied by electrostatic spray or other suitable method.9. Requirements for Coated Steel Reinforcing Bars9.1 Coating Thickness:A934/A934M 1339.1.1 The coating thickness on straight sections of bars, after curing, shall be 175 t
48、o 300 m 7 to 12 mils.The coating thicknesson bent sections of bars, after curing, shall be 175 to 405 mm 7 to 16 mils. Bent sections of bars are defined as the entire radiusof each bend and portions of the bar extending 150 mm 6 in. beyond the beginning and ending bend points on the bar. Bars thatar
49、e bent with a radius such as Bend Type 9 (Fig. 1) shall have the same coating thickness requirements as straight bars, when the“H“ dimension is equal to or less than one-half of the “R“ dimension.NOTE 8Section 9.1.1 permits a maximum coating thickness of 405 m 16 mils on bent sections of bars. Discussion of the effect of the permissibleincreased coating thickness on the anchorage capacity of bent bars embedded in concrete is presented in Appendix X3.9.1.2 A single recorded steel reinforcing bar coating thickness mea
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