1、Designation: C935 13Standard Specification forGeneral Requirements for Prestressed Concrete PolesStatically Cast1This standard is issued under the fixed designation C935; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers general requirements for pre-stressed concrete poles statically cast for use as structuralsu
3、pports for lights, distribution, transmission, and dead endpoles.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.2. Referenced Docume
4、nts2.1 ASTM Standards:2A36/A36M Specification for Carbon Structural SteelA82/A82M Specification for Steel Wire, Plain, for ConcreteReinforcementA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA416/A416M Specification for Steel Strand, UncoatedSeven-Wire for Prestressed Concr
5、eteA421/A421M Specification for Uncoated Stress-RelievedSteel Wire for Prestressed ConcreteA586 Specification for Zinc-Coated Parallel and HelicalSteel Wire Structural StrandA615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete ReinforcementA722/A722M Specification for Uncoa
6、ted High-StrengthSteel Bars for Prestressing ConcreteC31/C31M Practice for Making and Curing Concrete TestSpecimens in the FieldC33/C33M Specification for Concrete AggregatesC39/C39M Test Method for Compressive Strength of Cylin-drical Concrete SpecimensC42/C42M Test Method for Obtaining and Testing
7、 DrilledCores and Sawed Beams of ConcreteC94/C94M Specification for Ready-Mixed ConcreteC150/C150M Specification for Portland CementC172/C172M Practice for Sampling Freshly Mixed Con-creteC173/C173M Test Method for Air Content of Freshly MixedConcrete by the Volumetric MethodC231/C231M Test Method f
8、or Air Content of Freshly MixedConcrete by the Pressure MethodC260/C260M Specification for Air-Entraining Admixturesfor ConcreteC309 Specification for Liquid Membrane-Forming Com-pounds for Curing ConcreteC330/C330M Specification for Lightweight Aggregates forStructural ConcreteC403/C403M Test Metho
9、d for Time of Setting of ConcreteMixtures by Penetration ResistanceC494/C494M Specification for Chemical Admixtures forConcreteC595/C595M Specification for Blended Hydraulic CementsC618 Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in Concrete3. Basis of Acceptance3.1 Ac
10、ceptability of prestressed concrete poles produced inaccordance with this specification shall be determined by theresults of compressive strength tests of concrete cylinders andmill certificates for the reinforcing steel. A written statement,signed by the manufacturer, shall verify that the cement,a
11、ggregates, admixtures, and steel conform to the applicablespecifications for the material and that the preparation ofequipment, mixing, conveying, placing, consolidation, andcuring conforms to the requirements of the applicable standardspecifications. Concrete strength shall be determined by thecomp
12、ressive strength tests of cylinders. The manufacturersstatement shall also certify adherence to tolerance on dimen-sions. Acceptability of the concrete strength of completedprestressed concrete poles may also be determined by com-pression tests of concrete cores in accordance with TestMethod C42/C42
13、M.1This specification is under the jurisdiction ofASTM Committee C27 on PrecastConcrete Products and is the direct responsibility of Subcommittee C27.20 onArchitectural and Structural Products.Current edition approved April 1, 2013. Published April 2013. Originallyapproved in 1980. Last previous edi
14、tion approved in 2002 as C935 80 (2002)which was withdrawn January 2011 and reinstated in April 2013. DOI: 10.1520/C0935-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
15、efer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Materials4.1 CementPortland cement shall conform to the require-ments of Specification C150/C150M or shall be blendedhyd
16、raulic cement conforming to the requirements of Types ISor IP Specification C595/C595M.4.2 AggregateThe concrete shall be made with fine andcoarse aggregates that conform to Specification C33/C33M orC330/C330M. The nominal maximum size of the coarseaggregate shall not exceed15 the minimum dimension
17、of themember or34 of either the clear spacing between the reinforc-ing steel or the clear cover.4.3 WaterWater used for curing, for washing aggregates,and for mixing concrete shall be free of oils, organic materials,and other substances in amounts that may be deleterious toconcrete or steel, and it
18、shall not contain concentrations ofchloride ions in excess of 500 ppm or sulfate ions in excess of1000 ppm.4.4 AdmixturesAir-entraining admixtures shall conform toSpecification C260/C260M. Chemical admixtures shall con-form to Specification C494/C494M. Fly ash or other pozzo-lanic admixtures shall c
19、onform to the requirements of Speci-fication C618. Admixtures shall not contain chloride ions inquantities that will cause the total chloride content of theconcrete to exceed 0.06 %.4.5 SteelPrestressing steel shall conform to SpecificationsA416/A416M, A421/A421M, A586,orA722/A722M. Auxil-iary nonte
20、nsioned reinforcement shall conform to SpecificationA82/A82M or A615/A615M. Base plates, anchor bolts, andtop mount couplings shall conform to ASTM specificationsdesignated on contract drawings.5. Requirements5.1 Poles shall be designed to carry all forces associatedwith prestressing, handling, stor
21、age, installation, loading, andother service conditions. Consideration shall be given to thelevel of prestress forces both before and after losses.5.2 ConcreteConcrete shall have a minimum design com-pressive strength of 5000 psi (37.5 MPa) at 28 days.5.3 Concrete CoverThe minimum concrete cover ove
22、r thereinforcement shall be 1 in. (25 mm). Ends of prestressed steelshall be recessed14 in. (6 mm) and shall be covered with asuitable waterproofing product.5.4 Air EntrainmentUnless otherwise specified by thepurchaser, all concrete shall have an air content of 5 % plus orminus 1 % as measured by Te
23、st Method C173/C173M orC231/C231M.5.5 Lifting DevicesFlush inserts may be cast into the poleat locations agreeable to the purchaser. Removable attachmentsmay utilize the flush inserts to provide for lifting of the pole.Steel strand loops may be used instead of flush inserts forlifting. The loops sha
24、ll be installed with a recess in the pole thedepth of the required minimum concrete cover over thereinforcement, and a diameter no less than 114 in. (32 mm).Steel strand lifting loops shall be removed flush to the concretein the recess. The recess shall be filled and sealed withepoxy-based grout and
25、 the pole surface shall be troweled tomatch the finish. All repair work involved with the loops shallbe completed before delivery.5.6 GroundingIn order to provide good electricalcontinuity, the spiral steel shall be securely tied to eachreinforcing steel member it contacts within 1 ft (0.3 m) of the
26、top and the butt of the pole. An embedded ground wire orprovisions to attach a ground wire to the surface of the polemay be specified. The embedded ground wire shall be copperand not smaller than No. 6 AWG (4 mm). It shall be bondedwith a suitable electrical connector to the reinforcing steelwithin
27、2 ft (0.6 m) of both the top and butt of the pole.Grounding pigtail wire of soft-drawn stranded copper, notsmaller than No. 6 AWG (4 mm), shall be bonded with asuitable compression or mechanical connector to the embeddedground wire, and shall extend from the pole surface 4 6 1 in.(100 6 30 mm). Unle
28、ss otherwise specified, grounding pigtailsshall be located 3 ft (0.9 m) from the top and 4 ft (1.2 m) fromthe butt. Provisions to attach a ground wire to the surface of thepole must be specified by the purchaser. The type of fastener orprovisions for fastening to be supplied by the polemanufacturer,
29、 the location, the spacing, and any electricalconnection to the reinforcing steel must be covered in thepurchasers specifications.6. Manufacture6.1 MixtureThe aggregates shall be sized, graded,proportioned, and thoroughly mixed with proportions of ce-ment and water that will produce a concrete mixtu
30、re of qualitysuch that the poles will conform to the test and designrequirements of this specification. Concrete conforming toSpecification C94/C94M may be used.6.2 PlacingConcrete should be placed in the forms asnearly as possible in its final position. Special care should betaken to fill all parts
31、 of the forms, and to place concrete underand around all reinforcing steel. Reinforcement shall be ad-equately secured so as to remain in the proper position duringthe placing of the concrete. Tie wires, if used to fasten thereinforcing steel, shall be bent down to provide the maximumprotective cove
32、r of concrete over the wires.6.3 CuringPoles shall be cured by one of the followingmethods or combination thereof. They shall be cured so that theconcrete will develop the required compressive strength. Thetemperature of the concrete shall not exceed 100F (38C) nordrop below 40F (4C) for a minimum o
33、f 1 h after placingregardless of the curing option selected.6.3.1 Accelerated CuringPoles may be cured with eithersteam or radiant heat in a moist environment.6.3.2 Water CuringPoles may be water-cured by coveringwith water-saturated material or by a system of perforatedpipes.6.3.3 Membrane CuringA
34、curing compound conformingto the requirements of Specification C309 may be applied andshould be left intact until strength requirements are met. Theconcrete at the time of application shall be within 10F (6C)of the ambient air temperature. All surfaces shall be kept moistprior to the application of
35、the compounds and shall be dampwhen the compound is applied.C935 1326.3.4 Steam CuringSteam chamber shall be so con-structed to retain the live steam, to minimize moisture and heatlosses, to allow free air circulation of the steam around thepole. The steam jets shall be positioned so they do notdisc
36、harge directly on the forms or test cylinders. The cycle ofsteam curing shall conform to the following:6.3.4.1 After placing and vibration, the concrete shall beallowed to attain an initial set (approximately 500 psi (3.5MPa), determined by Test Method C403/C403M) before start-ing to raise the tempe
37、rature of concrete with the steam. If theambient temperature is below 50F (10C) enough heat shallbe applied to maintain the concrete at its placing temperature.6.3.4.2 The temperature rise in the curing enclosure shall beuniform with a rate of rise between 30F (17C) and 60F(33C) per hour. The concre
38、te shall be cured at a steamtemperature of 130F (54C) to 165F (74C) until the concretereaches the detensioning strength specified in 6.4.6.3.4.3 The concrete test cylinders shall be subject to thesame curing as the poles.6.3.4.4 Recording thermometers shall be used to record thetime-temperature rela
39、tionship through the curing period fromplacing concrete to the transfer of the prestressing.6.3.5 Curing OptionOther methods of curing may be usedif approved by the purchaser.6.4 Prestressing:6.4.1 Initial prestress shall not be applied until the concretestrength has reached the greater of 3500 psi
40、(24 MPa) or 1.67times the maximum expected stress in the concrete due to theprestressing forces immediately after transfer and before lossesoccur.6.4.2 Detensioning sequence of strands and wires shall bepredetermined to avoid undesired temporary stresses.6.5 ReinforcementSteel reinforcement shall co
41、nform tothe requirements set forth in this specification and shall beplaced in position in the form within specified tolerances.6.6 FormsForms shall be rigid and sufficiently strong tosupport the weight of the concrete without deformation ordeflection exceeding specified tolerances. Seepage of water
42、from the form shall be minimal. All forms shall be constructedso that they can be removed without damaging the concrete.All exposed concrete edges at an angle of 100 or less shall bebeveled.6.6.1 Cleaning and OilingForms shall be cleaned beforeeach use. New forms shall be free of paint or other prot
43、ectivecoatings that might cling to the surface of the members. Formsshall have a suitable release agent applied as necessary to aidin breaking bond between form wall and concrete.6.7 Concrete FinishConcrete finishing shall be as speci-fied by the purchaser.7. Physical Requirements7.1 Compression Tes
44、t SpecimensCompression tests forsatisfying the design concrete strength requirements shall bemade on standard concrete cylinders. Test cylinders shall beidentified with poles. Two cylinders will be required for each10 yd3(8 m3) with a minimum of two cylinders for eachcasting bed, whichever is the gr
45、eater number of cylinders, andshall be made at random from different batches. Compressiontest specimens for satisfying minimum specified concretestrength requirement shall be made in accordance with PracticeC31/C31M except that curing shall be in accordance with 7.2.7.2 Curing Compression Test Speci
46、mensTest specimensshall be cured in a manner similar to the poles if they aresteam-cured. If poles are cured at normal ambienttemperatures, the specimens shall be cured in accordance withPractice C31/C31M.7.3 Compression TestCylinders shall be tested in accor-dance with Test Method C39/C39M. The ave
47、rage compressivestrength of all cylinders tested for each days production shallbe equal to or greater than specified design strength of theconcrete. In no case shall any cylinder tested fall below 80 %of the design strength.7.4 Core Compression TestsIf the criteria of 7.3 are notmet or as an alterna
48、tive to 7.3, the producer or purchaser mayagree to use cores taken from the poles in accordance with TestMethod C42/C42M. The number of tests required shall be asspecified in 7.1. Test results shall conform to 7.3 except that ifcores are used, the average compressive strength of the testspecimens sh
49、all be equal to or greater than 4250 psi (29 MPa)or 85 % of fc, whichever is less. No single core shall have acompressive strength of less than 3750 psi (27 MPa). If thetests fail each pole or pole segment may be individually coredfor acceptance.8. Tolerances and Permissible Variations8.1 Cross Sectional DimensionsCross-sectional dimen-sions shall not deviate from design dimensions by more than14in. (6 mm).8.2 Longitudinal DimensionsLongitudinal dimensionsshall not deviate from the design dimensions by more than 1 in.(25 mm) from
