1、Designation: A882/A882M 04a (Reapproved 2010)Standard Specification forFilled Epoxy-Coated Seven-Wire Prestressing Steel Strand1This standard is issued under the fixed designation A882/A882M; the number immediately following the designation indicates the yearof original adoption or, in the case of r
2、evision, 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. Scope1.1 This specification covers ASTM Specification A416/A416M low-relaxation Grade 250 and Grade 270 se
3、ven-wireprestressing steel strand with protective fusion-bonded epoxycoating applied by the electrostatic deposition method or othermethod that will meet the coating requirements in Section 8,and, except as allowed by 1.2, with the interstices of the sevenwires filled with epoxy to minimize migratio
4、n of corrosivemedia, either by capillary action or other hydrostatic forces.NOTE 1The manufacturer as identified throughout this specification isthe coating applicator.1.2 Upon special request by the purchaser, the interstices areleft unfilled.NOTE 2Unfilled strand can corrode from the inside and it
5、s applicationfor prestressing tendons in concrete or for rock and soil anchors is notrecommended.1.3 This specification is applicable for orders in eitherinch-pound units (as Specification A882) or SI units asSpecification A882M.1.4 The values stated in either SI units or inch-pound unitsare to be r
6、egarded 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 non-conformancewith the standard.2. Referenced Documents2.1 ASTM Standards:2A370 Test Metho
7、ds and Definitions for Mechanical Testingof Steel ProductsA416/A416M Specification for Steel Strand, UncoatedSeven-Wire for Prestressed ConcreteB117 Practice for Operating Salt Spray (Fog) ApparatusD968 Test Methods for Abrasion Resistance of OrganicCoatings by Falling AbrasiveG12 Test Method for No
8、ndestructive Measurement of FilmThickness of Pipeline Coatings on SteelG14 Test Method for Impact Resistance of Pipeline Coat-ings (Falling Weight Test)G20 Test Method for Chemical Resistance of PipelineCoatings2.2 Federal Highway Administration Report:FHWA-RD-74-18 Nonmetallic Coatings for Concrete
9、 Rein-forcing Bars (February 1974)33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 disbondingloss of adhesion between the fusion-bonded epoxy coating and the steel strand wires.3.1.2 fusion-bonded epoxy coatinga product containingpigments, thermo-setting epoxy resins, cross-li
10、nking agents,and other substances, which is applied in the form of powderonto a clean, heated metallic substrate and fuses to form acontinuous barrier coating.3.1.3 gritinert particles impregnated on the outer surfaceof the epoxy coating for improving bond with cement grout.3.1.4 holidaya discontinu
11、ity in the coating that is notdiscernible to a person with normal or corrected vision.3.1.5 patching materiala liquid coating used to repairdamaged or uncoated areas.4. Ordering Information4.1 The purchaser should specify:4.1.1 Diameter, grade, and type of uncoated strand inaccordance with Specifica
12、tion A416/A416M (latest edition).4.1.2 Smooth or grit impregnated coating (see 7.3).4.1.3 Quantity (in feet metres).4.1.4 Requirements for certification (see A1.2.3).4.1.5 Requirements for material samples (see 5.3).4.1.6 Requirements for patching material (see 5.4).4.1.7 Number of pullout tests to
13、be performed, if any.NOTE 3A typical ordering description for epoxy-coated strand is asfollows: 84 000 feet 2560 m of grit-impregnated epoxy-coated strand,12-in. 12.7-mm diameter, Grade 270 K low-relaxation on wooden reelsto ASTM Specification A882 A882M .1This specification is under the jurisdictio
14、n of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved May 1, 2010. Published July 2010. Originally approvedin 1991. Last previous edition approved in 2004 as A882/A882M 04a. DOI:10.15
15、20/A0882_A0882M-04AR10.2For referenced 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 National Technical Inf
16、ormation Service (NTIS), 5285 PortRoyal Rd., Springfield, VA 22161, http:/www.ntis.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Materials5.1 Prestressing steel strand to be coated shall meet therequirements of Specification
17、A416/A416M as specified by thepurchaser and shall be free of contaminants such as oil, grease,or paint.5.1.1 Filled epoxy-coated strand shall have relaxation lossesof not more than 6.5 % after 1,000 hours, when initially loadedto 70 % of the specified minimum breaking strength of thestrand when test
18、ed under conditions of Specification A416/A416M.5.2 The coating material shall meet the requirements listedinAnnexA1 of this specification. The coating material shall beof organic composition except for the pigment, or grit ifapplicable, which may be inorganic if used.5.2.1 If specified in the order
19、, a written certification shall befurnished to the purchaser that properly identifies the numberof each batch of coating material used in the order, material,quantity represented, date of manufacture, name and address ofmanufacturer, a statement that the supplied coating materialmeets the requiremen
20、ts of Annex A1, and a statement that thecoating material used in each batch is the same material as thatwhich was qualified under the requirements of Annex A1.5.3 If specified in the order, a representative 8-oz 0.23-kgsample of coating material shall be packaged in an airtightcontainer and identifi
21、ed by batch number, and supplied to thepurchaser.5.4 If specified in the order, patching material compatiblewith the coating material and inert in concrete, and meeting therequirements of Annex A1 shall be supplied to the purchaser.6. Surface Preparation6.1 The surface of the steel strand to be coat
22、ed shall becleaned chemically or by another method that will impart thesame cleanliness to ensure that the coated strand meets therequirements of Section 8.7. Application of Coating7.1 The coating shall be applied to the cleaned surface assoon as possible after cleaning and before reoxidation of the
23、surface discernible to the unaided eye occurs. However, in nocase shall application of the coating be delayed more than 10min after cleaning, unless otherwise permitted by the pur-chaser.7.2 The coating shall be applied by the electrostatic depo-sition method, or other method that will meet the coat
24、ingrequirements in Section 8, and fully cured in accordance withthe recommendations of the manufacturer of the coatingmaterial.7.3 The coating may be smooth or grit-impregnated.7.3.1 Inert particles (grit) shall be impregnated into thesurface of the coating when grit-impregnated strand is ordered.Su
25、ch particles shall not cause the coating to fail the require-ments of Section 8. The particles shall be inert in concrete andnon-reactive with concrete additives and soluble salts.7.3.2 The epoxy on the surface of grit-impregnated strandshall be capable of reaching a temperature of 150F 66Cwithout r
26、educing the transfer of prestress by bond from thestrand to the surrounding concrete. (WarningAt tempera-tures above 165F 74C, currently available epoxy begins tosoften and lose its ability to transfer load from strand toconcrete by bond. At 200F 93C practically all transfercapacity will be lost.)8.
27、 Requirements for Coated Strands8.1 Thickness of Coating:8.1.1 The coating thickness after curing shall be 15 to 45mils 380 to 1140 m.8.1.2 The thickness of the coating film shall be determinedusing a magnetic gauge or other method. The gauge shall beused and calibrated in accordance with the manufa
28、cturersrecommendations and Section 5 of Test Method G12, exceptthat in 5.2.1 of Test Method G12, the foil shall be placed on thesurface of the bare strand instead of the steel plate. The gaugeshall be capable of measuring the coating thickness of a coatedwire of circular cross-section with a diamete
29、r in the range of0.1 to 0.3 in. 2.5 to 7.5 mm. The allowable error on a singlemeasurement of the coating thickness on the coated crown ofan outer wire of the strand shall be 65%.8.1.3 The coating thickness shall be measured on the crownof each of the six outer wires at least every 2000 ft 600 m ofco
30、ntinuous strand. The average of the coating thickness mea-surements for each set of six outer wires shall be supplied tothe purchaser upon request. Records of inspection duringmanufacture shall also be made available when requested.8.2 Continuity of Coating:8.2.1 After application of the coating, a
31、continuous in-lineholiday detection procedure shall be employed using anaqueous electrolyte and a holiday detector with a minimumvoltage setting of 67.5 V DC, following the procedure fur-nished by its manufacturer. The approximate location ofholidays shall be recorded using automatic devices or mark
32、ingson the strand for later patching.8.2.2 The coated strand shall only be required to meet theholiday requirements of this specification with the in-lineholiday detector, but shall not be required to pass holidayinspection performed on stationary strand for residence timesexceeding 3 seconds.8.2.3
33、During the continuous holiday detection procedure,coated strand containing more than two holidays per hundredfeet 30 m shall be rejected and corrective action for theepoxy-coating process shall be instituted. Coated strand withtwo holidays or less per hundred feet 30 metres shall bepatched in accord
34、ance with the patching material manufactur-ers recommendation. Patching of holidays shall be performedsuch that the total of the thicknesses of the coating and thepatch does not exceed 1.1 mm 45 mils.NOTE 4Hand-held holiday detector checks should be performedregularly to verify the accuracy of the i
35、n-line system.8.3 Adhesion of Coating:8.3.1 The adhesion and shear strength of the coating shall beevaluated by bending a sample from a finished reel of coatedstrand 180 around a mandrel diameter equal to 32 times thenominal diameter of the strand. Test specimens shall be atthermal equilibrium betwe
36、en 68 and 86F 20 and 30C.8.3.2 No cracking or disbonding of the coating shall bevisible to the unaided eye on the outside radius of the bentA882/A882M 04a (2010)2strand. Evidence of cracking or disbonding of the coating shallbe considered cause for rejection of the coated strand repre-sented by the
37、bend test sample. Retests shall be conducted inaccordance with 10.1.8.3.3 Fracture of the steel wire or strand in the bend test foradhesion of coating shall not be considered as an adhesionfailure of the coating, and another specimen from the sameproduction shift may be substituted.8.3.4 The adhesio
38、n of coating shall also be evaluated by atension test in accordance with Section 6 of SpecificationA416/A416M. The coated strand shall satisfy the requirementsfor breaking strength, yield strength (1 % extension), andultimate elongation described in Specification A416/A416M.No cracks visible to the
39、unaided eye shall occur in the coatingup to an elongation of 1 % (yield strength).8.3.5 Sample length for the bend test shall be at least 5 ft, 0in. long 1500 mm. Sample length for the tension test shallfollow the requirements of Test Methods and DefinitionsA370.8.4 Bond with Concrete or Grout:8.4.1
40、 Pull-out tests shall be conducted on grit-impregnatedcoated strand to ensure proper bond properties. Pull-out speci-mens shall be cast in concrete cylinders with dimensionsshown in Table 1. The untensioned strand shall be embeddedconcentrically along the longitudinal axis of the specimen. Theminimu
41、m force at 0.001 in. 0.025 mm slip shall be applied asshown in Fig. 1, by a hydraulic or mechanical jack whenconcrete reaches a compressive strength between 4000 and5000 psi 30 and 35 MPa, and measured with a calibrated loadindicator at a slip of 0.001 in. 0.025 mm.Adial gage shall beused at the unl
42、oaded end to indicate slip. Minimum force at0.001 in. 0.025 mm slip shall be at least equal to or greaterthan the values shown in Table 1.9. Number of Tests9.1 Three pullout tests shall be performed annually as aminimum or repeated when a process change is made thatcould decrease the bond capacity o
43、f the epoxy-coated strand.The purchaser shall have the right to request additional pullouttests to be performed on the lot of epoxy-coated strand ordered.10. Retests10.1 If the specimen for coating thickness, continuity, ad-hesion of coating, and pull-out tests fail to meet the specifiedrequirements
44、, two retest samples adjacent to the first samplefrom the same reel shall be conducted for each failed test. If theresults of both retests meet the specified requirements, the reelsrepresented by the samples shall be accepted.11. Inspection11.1 The inspector representing the purchaser shall havefree
45、 entry while work on the contract of the purchaser is beingperformed. The manufacturer shall afford the inspector allreasonable facilities to satisfy him that the material is beingfurnished in accordance with this specification. All tests andinspection shall be made at the place of manufacture prior
46、 toshipment, unless otherwise specified, and shall be conducted sothere is no unnecessary interference with the manufacturersoperation.12. Rejection12.1 Except as specified in 10.1, coated strand reels repre-sented by test samples that do not meet the requirements of thisspecification shall be rejec
47、ted.12.2 A reel of coated strand that is rejected for thickness orcontinuity of coating shall be accepted if the non-conformingsections are removed and the remaining material meets thecoating requirements of this specification.13. Certification13.1 If outside inspection is waived, a manufacturers ce
48、r-tification that the material has been tested in accordance withand meets the requirements of this specification shall be thebasis of acceptance of the material. The certification shallinclude the specification number, year-date of issue, andrevision letter, if any.13.2 The manufacturer shall, when
49、 requested in the order,furnish a representative load-elongation curve for each size andgrade of strand shipped and a copy of the manufacturersquality control tests.14. Handling and Identification14.1 All strapping bands shall be padded or suitable bandingshall be used to prevent damage to the coating. All reels ofcoated strand shall be handled in such a manner as not todamage the coating on the strand.14.2 Coating damage due to handling shall be repaired inaccordance with the recommendation of the manufacturer
