1、Designation: A775/A775M 17Standard Specification forEpoxy-Coated Steel Reinforcing Bars1This standard is issued under the fixed designation A775/A775M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A nu
2、mber 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 This specification covers deformed and plain steel
3、reinforcing bars with protective epoxy coating applied by theelectrostatic spray method.NOTE 1The coating applicator is identified throughout this specifica-tion as the manufacturer.1.2 Other organic coatings may be used provided they meetthe requirements of this specification.1.3 Requirements for c
4、oatings are contained in Annex A1.1.4 Requirements for patching material are contained inAnnex A2.1.5 Guidelines for construction practices at the job-site arepresented in Appendix X1.1.6 This specification is applicable for orders in either SIunits (as Specification A775M) or inch-pound units as Sp
5、eci-fication A775.1.7 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in no
6、n-conformancewith the standard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitatio
7、ns 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 Deformed and Plain Low-Alloy Steel Bars for Concrete ReinforcementA944 Test Method for Comparing Bond Strength of SteelR
8、einforcing Bars to Concrete Using Beam-End Speci-mensA996/A996M Specification for Rail-Steel and Axle-SteelDeformed Bars for Concrete ReinforcementB117 Practice for Operating Salt Spray (Fog) ApparatusD374 Test Methods for Thickness of Solid Electrical Insu-lation (Metric) D0374_D0374MD2967 Test Met
9、hod for Corner Coverage of Powder Coat-ingsD4060 Test Method for Abrasion Resistance of OrganicCoatings by the Taber AbraserG8 Test Methods for Cathodic Disbonding of Pipeline Coat-ingsG14 Test Method for Impact Resistance of Pipeline Coatings(Falling Weight Test)G20 Test Method for Chemical Resista
10、nce of Pipeline Coat-ingsG62 Test Methods for Holiday Detection in Pipeline Coat-ings2.2 NACE Standards:3RP-287-87 Field Measurement of Surface Profile of Abra-sive Blast-Cleaned Steel Surface Using a Replica Tape2.3 SSPC Specifications:4SSPC-PA 2 Measurement of Dry Coating Thickness withMagnetic Ga
11、gesSSPC-SP 10 Near-White Blast CleaningSSPC-VIS 1 Pictorial Surface Preparation Standards forPainting Steel Surfaces2.4 CRSI Documents:5“Voluntary Certification Program for Fusion Bonded EpoxyCoating Applicator Plants”1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stain
12、less Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved Jan. 1, 2017. Published January 2017. Originallyapproved in 1981. Last previous edition approved in 2016 as A775/A775M 16.DOI: 10.1520/A0775_A0775M-17.2For referenced
13、ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from NACE International (NACE), 1440 South Creek Dr., Houston,TX 7
14、7084-4906, http:/www.nace.org.4Available from Society for Protective Coatings (SSPC), 40 24th St., 6th Floor,Pittsburgh, PA 15222-4656, http:/www.sspc.org.5Available from Concrete Reinforcing Steel Institute (CRSI), 933 North PlumGrove Rd., Schaumburg, IL 601734758, http:/www.crsi.org.*A Summary of
15、Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the
16、 Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.12.5 ACI Standards:6ACI 301 Specifications for Structural Concrete3. Terminology3.1 Definitions of Terms Specific to Th
17、is Standard:3.1.1 conversion coating, npreparation of the blast-cleaned steel surface prior to coating application that isdesigned to pretreat the metal to promote coating adhesion,reduce metal-coating reactions, improve corrosion resistance,and increase blister resistance.3.1.2 disbonding, nloss of
18、 adhesion between the fusion-bonded epoxy coating and the steel reinforcing bar.3.1.3 fusion-bonded epoxy coating, nproduct containingpigments, thermosetting epoxy resins, crosslinking agents, andother additives, which is applied in the form of a powder ontoa clean, heated metallic substrate and fus
19、es to form a continu-ous barrier coating.3.1.4 holiday, ndiscontinuity in a coating that is notdiscernible to a person with normal or corrected vision.3.1.5 patching material, nliquid two-part epoxy coatingused to repair damaged or uncoated areas.3.1.6 wetting agent, nmaterial that lowers the surfac
20、etension of water allowing it to penetrate more effectively intosmall discontinuities in the coating giving a more accurateindication of the holiday count.4. Ordering Information4.1 It shall be the responsibility of the purchaser to specifyall requirements that are necessary for the coated steel rei
21、n-forcing bars under this specification. Such requirements to beconsidered include, but are not limited to, the following:4.1.1 Reinforcing bar specification and year of issue,4.1.2 Quantity of bars,4.1.3 Size and grade of bars,4.1.4 Requirements for the powder coating and provision oftest data (5.2
22、 and 5.3),4.1.5 Requirements for patching material (5.4.2),4.1.6 Quantity of patching material,4.1.7 Specific requirements for test frequency (9.1),4.1.8 Whether a report on tests performed on the coatedsteel reinforcing bars being furnished is required (14),4.1.9 Requirements for inspection (12.1),
23、 and4.1.10 Manufacturer qualification and certification require-ments (if any).NOTE 2It is recommended that the coating application procedures andprocesses be audited by an independent certification program for epoxycoating applicator plants such as that provided by the Concrete Reinforc-ing Steel I
24、nstitute, or equivalent.NOTE 3A typical ordering description is as follows: Deformed Grade420 bars to ASTM A615M_; 6000 m, No. 19, 12 m long in securedlifts with sufficient spacers or padding, or both; epoxy-coated to ASTMA775M_; including written certifications for the powder coatingand coated bars
25、, and 1 L of patching material.Deformed Grade 60 bars to ASTM A615M_; 20 000 ft, No. 6,40 ft 0 in. long in secured lifts with sufficient spacers or padding, or both;epoxy-coated to ASTM A775_; including written certifications forthe powder coating and coated bars, and 1 qt of patching material.5. Ma
26、terials5.1 Steel reinforcing bars to be coated shall meet therequirements of one of the following specifications: A615M,A706M, or A996M A615, A706, or A996, as specified by thepurchaser and shall be free of contaminants such as oil, grease,or paint.NOTE 4Prior to coating, the steel reinforcing bars
27、should be inspectedfor their suitability for coating. Bars with sharp edges on the deformations,rolled-in slivers, or other surface imperfections are difficult to coatproperly and should not be coated. The coating will flow away from thesharp edges and may result in inadequate coating thickness at t
28、hese points.5.2 The powder coating shall meet the requirements ofAnnex A1. Upon request, the purchaser shall be provided withthe test report for review.5.2.1 A written certification shall be furnished to the pur-chaser that properly identifies the number of each lot of powdercoating used in the orde
29、r, material quantity represented, date ofmanufacture, name and address of the powder coatingmanufacturer, and a statement that the supplied powder coatingis the same composition as that qualified according to AnnexA1 of this specification.5.2.2 The powder coating shall be stored in a temperature-con
30、trolled environment following the written recommenda-tions of the powder coating manufacturer until ready for use.At that point, if the storage temperature is below the plantambient temperature, the powder coating shall be given suffi-cient time to reach approximate plant ambient temperature.The pow
31、der coating shall be used within the powder coatingmanufacturers written recommended shelf life.5.3 If specified in the order, a representative 0.2-kg 8-ozsample of the powder coating shall be supplied to the purchaserfrom each batch. The sample shall be packaged in an airtightcontainer and identifi
32、ed by batch number.5.4 Patching material for repairing damaged coating shall becompatible with the coating, inert in concrete, and feasible forrepairs at the applicator plant or at the fabricating shop.Patching material shall be approved in accordance with AnnexA2 prior to use.5.4.1 The patching mat
33、erial manufacturer shall specify themetals surface preparation, and the procedures for applicationof the patching material.5.4.2 If specified in the order, patching material conformingto Annex A2 and recommended by the powder coatingmanufacturer shall be supplied to the purchaser.6. Surface Preparat
34、ion6.1 The surface of the steel reinforcing bars to be coatedshall be cleaned by abrasive blast cleaning to near-white metalin accordance with SSPC-SP 10. Additional surface treatment,as indicated in 6.3, is permitted. Use of SSPC-VIS 1 as a visualstandard of comparison to define the final surface c
35、ondition ispermitted. Average blast profile maximum roughness depthreadings of 0.04 to 0.10 mm 1.5 to 4.0 mils, as determined byreplica tape measurements using NACE RP-287-87, shall beconsidered suitable as an anchor pattern.6Available fromAmerican Concrete Institute (ACI), P.O. Box 9094, Farmington
36、Hills, MI 48333-9094, http:/www.concrete.org.A775/A775M 172NOTE 5The use of a “profilometer” type surface measurementinstrument that measures the peak count as well as the maximum profiledepth is recommended.NOTE 6Abrasive blast cleaning of steel reinforcing bars with a highdegree (90 %) of grit in
37、the cleaning media provides the most suitableanchor profile for coating adhesion. After grit has been recycled, a smallportion will take on the appearance of shot.6.2 Multidirectional, high-pressure dry air knives shall beused after blasting to remove dust, grit, and other foreignmatter from the bla
38、st-cleaned steel surface. The air knives shallnot deposit oil on the steel reinforcing bars.NOTE 7It is recommended that incoming steel reinforcing bars andblast media be checked for salt contamination prior to use. Blast mediafound to be salt contaminated should be rejected. Steel reinforcing barsf
39、ound to be salt contaminated from exposure to deicing salts or salt sprayshould be cleaned by acid washing or other suitable methods to removesalt contaminants from the surface prior to blast cleaning.6.3 It shall be permissible for the manufacturer to use achemical wash or conversion of the blast-c
40、leaned steel rein-forcing bar surface, or both, to enhance coating adhesion. Thispretreatment shall be applied after abrasive cleaning and beforecoating, in accordance with the written application instructionsspecified by the pretreatment manufacturer.7. Coating Application7.1 If pretreatment is use
41、d in the preparation of the surface,the powder coating shall be applied to the cleaned andpretreated steel reinforcing bar surface as soon as possible aftersurface treatments have been completed, and before visibleoxidation of the surface occurs as discernible to a person withnormal or corrected vis
42、ion. In no case shall application of thecoating be delayed more than 3 h after cleaning.7.2 The fusion-bonded epoxy powder coating shall beapplied in accordance with the written recommendations of themanufacturer of the powder coating for initial steel surfacetemperature range and post application c
43、uring requirements.During continuous operations, the temperature of the surfaceimmediately prior to coating shall be measured using infraredguns or temperature indicating crayons, or both, at least onceevery 30 min.NOTE 8The use of infrared and temperature-indicating crayon mea-surement of the steel
44、 reinforcing bars is recommended.7.3 The powder coating shall be applied by electrostaticspray or other suitable method.8. Requirements for Coated Steel Reinforcing Bars8.1 Coating Thickness:8.1.1 The coating thickness measurements after curing shallbe 175 to 300 m 7 to 12 mils for bars sizes Nos. 1
45、0 to 16Nos. 3 to 5 and 175 to 400 m 7 to 16 mils for bar sizesNos. 19 to 57 Nos. 6 to 18. The upper thickness limit shall notapply to repaired areas of damaged coating.8.1.2 A single recorded steel reinforcing bar coating thick-ness measurement is the average of three individual gagereadings obtaine
46、d between four consecutive deformations. Aminimum of five recorded measurements shall be taken ap-proximately evenly spaced along each side of the test speci-mens (a minimum of ten recorded measurements per bar).8.1.3 For acceptance purposes, the average of all recordedcoating thickness measurements
47、 shall not be less than thespecified minimum thickness or more than the specifiedmaximum thickness. No single recorded coating thicknessmeasurement shall be less than 80 % of the specified minimumthickness or more than 120 % of the specified maximumthickness.8.1.4 Measurements shall be made in accor
48、dance withSSPC-PA 2, following the instructions for calibration and userecommended by the thickness gage manufacturer. Pull-off orfixed probe gages shall be used. “Pencil-type” pull-off gagesthat require the operator to observe the reading at the instantthe magnet is pulled from the surface shall no
49、t be used.8.1.5 The coating thickness shall be measured on the bodyof a straight length of steel reinforcing bar between thedeformations.8.2 Coating Continuity:8.2.1 The manufacturers plant shall have an operationalin-line 67.5 V, 80 000 , wet-sponge type direct-currentholiday detector or equivalent method with an automatedholiday counting system to determine the acceptability of thesteel reinforcing bars prior to shipment.NOTE 9Handheld holiday detector checks should be performed eachproduction day to verify the accuracy
