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    I S 785: 998

    Indian StandardREINFORCED CONCRETE POLES FOR OVERHEAD

    POWER AND TELECOMMUNICATION LINES -SPECIFICATIONSecond Revision )

    ICS 91.100.30

    0 BIS 1998BUREAU OF INDIAN STANDARDSMANAKBHAVAN,9 BAHADURSHAHZAFARMARGNEW DELHI llOiJO2

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    Cement Matrix Products Sectional Committee, CED 53

    FOREWORDThis Indian Standard ( Second Revision ) was adopted by the Bureau of Indian Standards, after the draft finalizedby the Cement Matrix Products Sectional Committee had been approved by the Civil Engineering Division Council.This specification has been prepared with a view to clarifying and defining design requirements for differenttypes of reinforced cement concrete poles used in overhead electric power transmission, telephone andtelegraphs circuits. The specification relates to concrete poles in the manufacture of which mechanical compactingmethods, such as vibration, shocking, spinning, etc, have been adopted, and does not relate to hand compactedpoles.This standard was first published in 1957 and subsequently revised in 1964. The present revision has been takenup with a view to incorporating the modification found necessary in the light of experience gained with the useof this standard and due to revision of various referred standards, This revision incorporates significant modificationsin respect of materials, design, depth of planting, testing, sampling and inspection.The composition of the technical committee responsible for the formulation of this standard is given inAnnex B.For the purpose of deciding whether a particular requirement of this standard is complied with, the final value,observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2:1960 Rules for rounding off numerical values (revised). The number of significant places retained in the roundedoff value should be the same as that of the specified value in this standard.

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    Indian StandardREINFORCED CONCRETE POLES FOR OVERHEAD

    POWER AND TELECOMMUNICATION LINES -SPECIFICATIONSecond Revision )

    IS 785:1998

    1 SCOPE 3.5 Working LoadThis standard covers reinforced concrete poles suitablefor use in overhead power, traction and tele-communication lines. This standard does not coverprestressed concrete poles or prestressed concretepoles using untensioned reinforcement.

    The maximum load in the transverse direction, that is,ever likely to occur, including the wind pressure onthe pole. This load is assumed to get at a point600 mm below the top with the butt, end of the poleplanted to the required depth as intended in the design.

    2 REFERJENCES 4 OVERALL LENGTH OF POLESThe Indian Standards listed in Annex A containprovisions which, through reference in this text,constitute provision of this standard. At the time ofpublication, the editions indicated were valid. Allstandards are subject to revision, and parties toagreements based on this standard are encouraged toinvestigate the possibility of applying the most recenteditions of the standards listed in Annex A.

    4.1 The minimum overall length of poles shall be 6 mand the maximum overall length shall not exceed 9 m.Further, the lengths shall be in steps of 0.5 m.4.2 TolerancesThe tolerances for reinforced concrete poles shall beas under:

    3TllBMlNoL4JGY a) Overall length of poles il5mm3.0 For the purpose of this standard, the followingdefinitions shall apply.

    b) Cross-sectional dimension +5mm-3mm3.1 Ultimate FailureThe conditions existing when the pole ceasesto sustaina load increment owing to either crushing of concrete,snapping or permanent stretching of the reinforcingsteel in any part of the pole.

    c) Uprightness or straightness5 MATERIALS5.1 CementThe cement used in the manufacture of reinforcedconcrete poles shall be any of the following:.3.2 Load Factor

    The ratio of ultimate transverse load to the transverseload at first crack. For design the transverse load atfirst crack shaIl be taken as not less than the value ofthe working load.

    a) 33 grade ordinary Portland cement conformingto IS 269,W 43gradeordinaryPortlandcement~ormning

    to IS 8112,3.3 Transverse clThe direction of the line bisecting the angle containedby the conductor at the pole. In the case of straightrunthiswillbenormaltotherunofthepole.

    53 grade ordinary Portland cement conformingto IS 12269,

    4e)

    Portland slag cement conforming to IS 455,3.4 UIthnate Transverse LoadThe load at which failure occurs, when it is applied ata point 600 mmbelow the top and perpendicular to theaxis of the pole along the transverse direction withthe butt end of the pole planted to the required depthas intended in the design.

    4

    s)

    Portlandpozzolanacement:Part1Plyashbasedconforming to IS 1489 (Part l),Portland pozzolana cement : Part 2 Calcinedclaybased conforming to IS 1489 (Part 2) andRapid hardening Portland cement conformingto IS 8041.

    0.5 percent

    1

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    IS 785 : 19985.2 Aggregates Table 1 Minimum Depth of Planting ofReinforced Concrete Poles in the GroundAggregates used for the manufacture of reinforcedconcretepolesshallconformtoIS383.Wherespecilied,a sample of the aggregate shall be submitted by themanufacturer to the purchaser for approval.5.3 ReinforcementReinforcing bars and wires used for the manufactnreof reinforced concrete poles shall conform to the

    (Clause 6.3 )Length of Pole Minimum Depth of Plantingin Ground

    c:j6.0 to 7.0 1 207.5 to 9.0 1 50following: 6.4 Transverse Strength at Failure

    a) Mild steel and medium tensile steel bars andhard-drawn steel wires conforming to The poles shall be so designed that its strength inIS 432 (Part 1) and IS 432 (Part 2), and transverse direction shall be sufficient to take the loaddue to wind on wires and poles, multiplied by load

    b) High strength deformed bars and wiresconforming to IS 1786.

    5.3.1 The surface of all reinforcement shall be freefrom loose scale, loose rust, oil, grease, clay or othermaterial that may have deteriorating effect on the bondbetween the reinforcement and the concrete.

    factor. Where specifically- stated, snow load shallalso be taken into consideration. The design shall alsoensnre that, at design working load, the stresses andstrains are such as not to cause any harmful crackingin the pole.6.4.1 The strength of the pole in the direction of theline shall not be less than one-quarter of the strengthrequired in the transverse direction.6.4.2 The load factor on transverse strength forreinforced concrete poles shall not be less than 2.6.4.3 Poies intended to be fitted with stays or strutsshall be designed accordingly, and if required by thepurchaser, they shall be appropriately tested.6.5 Method of selection of reinforced concrete polein any given situation shall be as specified inIS7321.7MANUpACIURE7.1 All reinforcement shall be accurately placed andmaintained in position during manufacture. Allbuttons or chairs or other devices used to obtain thenecessary cover shall be of corrosion-resistant material.7.2 Cover

    5.4 AdmixtureAdmixtures if used shall conform to IS 9 103.5.5 ConcreteMinimum grade of concrete used for the mamrfactureof reinforced concrete poles shall be M 25.5.6 WaterThe requirement of water used for mixing and curingshall conform to the requirements given in IS 456.Sea water shall not be used.6 DESIGN6.1 The poles shall be so designed that they do notfail owing to failure initiated by compression inconcrete.6.2 LoadingThe maximum wind pressure to be assumed forcompuringthe signworkingloadshallbeasspecifiedby the State Governments, who are empowered in thisbehalf under the I ndian Electri city Rules, 1956. Windpressure may also be determined as specified inIS 875 (Part 3).6.3 Depth of PlantingThemi .mum depth ofplanting of a pole below groundlevel shall be in accordance with Table 1, the actualdepth being determined on the basis of groundconditions.

    The cover of concrete overall reinforcement shall beatleast equal to the maximum size of aggregate plus2 mm but in no case less than 20 mm.7.3 Welding and Lapping of ReinfomementWelding and lapping of reinforcement shall be as givenin IS 456.7.4 Forms7.4.1 Forms shall be of the shape required and shallbe so constructed as to maintain their shape duringthe placing and compaction of the concrete. They shallbe sufliciently tight to prevent loss of liquid from theconcrete.

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    7.42 Removal of FormsForms shall not be removed until the concrete hashardened sufficiently so that the surface is not marredby the removal of the forms. Poles shall not be moveduntil the concrete has attained sufficient strength towithstand the stresses introduced during demoulding.7.5 Placing, Compaction and Curing of Concrete7.5.1 The concrete shall be used as soon as possibleafter being mixed and no material which has developedan initial set shall be used in the work. After the concretehas been placed in the moulds and compacted, it shallnot be disturbed during the period of setting. Fordepositing concrete in hot weather, IS 786 1 (Part 1)may be referred.7.5.2 CompactingConcrete shall be compacted by spinning, vibrating,shocking or other suitable mechanical means. Handcompaction shall not be permitted.7.5.3 CuringAfter placing, the concrete shall be adequately protected,during setting and in the first stages of hardening,from shocks, running or surface water and the harmfuleffects of sunshine, drying winds and cold. Theconcrete shall be cured for at least 28 days unlessspecial curing methods are adopted, in such cases itshall be cured till the required strength is achieved.Steam curing of concrete may be adopted if so desiredby the manufacturer provided the requirements ofpressure or non-pressure steam curing are fulfilled.7.6 FinishThe concrete when removed from the mould shall beof good finish and free from honeycombing. All arrisesshall be clean and true and shall present a neatappearance.7.7 Tests on ConcreteDuring manufacture, test on concrete shall be carriedout as specified in IS 456. The manufacturer shallsupply when required by the purchaser of hisrepresentative, results of compressive test on concretecylinders or cubes made from the concrete used forthe poles. If the purchaser so desires, the manufacturershall supply cylinders or cubes for test purposes andsuch cylinders or cubes shall be tested in accordancewith IS 5 16 .7.8 Earthing7.8.1 Earthing shall be provided by one of the followingmeans:

    b)

    IS 785 : 19Y8dia galvanized iron wire embedded in concreteduring manufacture and the ends of the stripor cable left projecting from the pole to a lengthof 50 mm at 2 15 mm from top and 1 )111111e1011ground level (see Fig. 1).By providing two holes of suitable dimensions2 15 mm from top and 1SO mm belou groundlevel (see Fig. 1) to enable 25 mm x 3 mm copperstrip or equivalent bare copper cable to betaken from the top hole to the bottom throughthe central hole.

    7.8.2 The purchaser shall specify the type of earthingto be provided.7.9 HolesDuring manufacture, sufficient holes shall be providedin the poles for the attachment of cross arms and otherequipment. A typical arrangement of holes shown inFig. 1 permits the use of reinforced concrete poles inconjunction with wood or steel cross arms. but otherarrangements may be specified by the user. Holes forkicking block may be provided. if necessary.7.10 Eye HookTo facilitate handling of poles during transport anderection, an eyehook may be provided suitably in everypole below ground level on the face of the poles soas to utilize the maximum flexural strength of the sectionduring handling.8 TESTS8.1 Transverse Strength TestThe transverse strength test of reinforced concretepoles shall be conducted in accordance with IS 2905.A reinforced concrete pole shall be deemed notto have passed the test if the observed ultimatetransverse load is less than the design ultimatetransverse load.9 SAMPLING AND INSPECTION9.1 Scale of Sampling9.1.1 LotIn a consignment of 500 poles or a part thereof thesame mounting height, same dimensions and belongingto the same batch of manufacture shall be groupedtogether to constitute a lot.9.1.2 For ascertaining the conformity of the materialsin the lot to the requirements of this specification,samples shall be tested from each lot separately.

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    IS 785 : 1998

    TOP HOLE FOREARTHING OR ENDOF EARTHING

    ENLARGED DETAILOF TOP PORTION

    KICKING BLOCK:

    ENLARGEDSECTION XX

    NOTES1 All holes except where otherwise specified shall be of 20 mm dia.2 This figure gives information on holes and marking only and should not be used as a basis for design

    All dimensions in millimetres.FIG.1TYPICAL ETAILS FPOLE NDIRECIYONFLINE

    9 2 Number of Tests and Criteria for Conformity9.2.1 All the poles selected according to 9.1.3 shallbe tested for overall length, cross-section anduprightness (see 4.2). A pole failing to satisfjr one ormore of these requirements shall be considereddefective. All the poles in the lot shall be consideredas conforming to these requirements if the number ofdefective poles found in the sample is less than orequal to the corresponding acceptance number givenin co1 3 of Table 2.9.2.2 The lot having been found satisfactory accordingto 9.2.1 shall be further tested for transverse strength(see 8.1) of the poles. For this purpose, the number

    Table 2 Scale of Sampling and PermissibleNumber of Defectives(Clauses9.1.3,9.2.1und9.2.2)

    No. of Poles Sample Dimensional Transversein the Lot Size Requirements Strength

    Acceptance TestNumber

    (1) (2) (3) (4)up to 100 10 1 2101 200 15 1 3201 300 20 2 4301 U 500 30 3 5

    NOTE -- The number of poles to be tested shall be

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    according to 9.2.1 and found satisfactory. All thesepoles tested for transverse strength shall satisfy thecorresponding specification requirements. If one ormore poles fail, twice the number of poles orginallytested shall be selected from those already selectedand subjected to this test. If there is no failure amongpoles, the lot shall be considered to have satisfied therequirements of this test.10 MARKING10.1 The poles shall be clearly and indelibly markedwith the following particulars either curing or after themanufacture, but before testing, at a position so as tobe clearly read after erection in position:

    a) Indication of the source of manufacture,

    Wc)4

    10.2

    IS 785 : 1998Month and year of manufacture,Serial number of the poles, andPosition of centre of gravity of the poles withthe words C.G.

    BIS Certification MarkingThe poles may also be marked with the Standard Mark.10.2.1 The use of the Standard Mark is governed bythe provisions of the Bureau of I ndian StandardsAct, 1986 and the Rules and Regulations madethereunder. The details of conditions under which thelicence for the use of Standard Mark may be grantedto manufacturers or producers may be obtained fromthe Bureau of Indian Standards.

    ANNEX Al ause 2 >

    LIST OF REFERRED INDIAN STANDARDS

    IS No269 : 1989383 : 1970

    432

    Part 1) : 1982(Part2) : 1982

    455 : 1989456 : 1978516 : 1959875(Part 3) : 1987

    1489

    lWeSpecification for 3 3 grade ordinaryPortland cement fourth revision)Specification for coarse and fineaggregates from natural sources forconcrete second revision)Specification for mild steel andmedium tensile steel bars and hard-drawn steel wire for concretereinforcementMild steel and medium tensile steelbars third revision)Hard drawn steel wire thirdrevision)Specification for Portland slagcement fbrth revision)Code of practice for plain andreinforced concrete third revision)Method of test for strength ofconcreteCode of practice for design loads(other than earthquake) for buildingsand structures : Part 3 Wind loadssecond revision)

    Speciflcation for Portland pozzolanacement:

    S No(Part 1): 1991(Part 2) : 1991

    1786 : 1985

    2905 : 1989

    7321: 1974

    7861(Part 1) : 19758041: 19908112 : 19899103 : 197912269 : 1987

    iWeFlyash based third revision)Calcined clay based third revision)Specification for high strengthdef~steelbarswimsforconcmtereinforcement third revision)Method of test for concrete polesfor overhead power andtelecommunication lines firstrevision)Code of practice for selection,handling and erection of concretepoles for overhead power andtelecommunication linesCode ofpractice for extreme weatherconcreting : Part 1 Recommendedpractice for hot weather concretingSpecification for rapid hardeningPortland cement j?rst r evision)Specification for 43 grade ordinaryPortland cement yirst revision)Specification for admixture forconcreteSpecification for 53 grade ordinaryPortland cement

    http://../link/31to60/383.Bishttp://../link/31to60/432_1.Bishttp://../link/31to60/432_1.Bishttp://../link/31to60/432_1.Bishttp://../link/31to60/432_1.Bishttp://../link/31to60/432_2.Bishttp://../link/31to60/432_2.Bishttp://../link/31to60/432_2.Bishttp://../link/31to60/455.Bishttp://../link/31to60/455.Bishttp://../link/31to60/455.Bishttp://../link/31to60/456.Bishttp://../link/31to60/456.Bishttp://../link/31to60/456.Bishttp://../link/31to60/516.Bishttp://../link/31to60/516.Bishttp://../link/31to60/516.Bishttp://../link/61to88/875_3.Bishttp://../link/61to88/875_3.Bishttp://../link/61to88/875_3.Bishttp://../link/15to30/1786.Bishttp://../link/15to30/1786.Bishttp://../link/15to30/1786.Bishttp://../link/15to30/2905.Bishttp://../link/15to30/2905.Bishttp://../link/15to30/2905.Bishttp://../link/61to88/7321.Bishttp://../link/61to88/7861_1.Bishttp://../link/61to88/7861_1.Bishttp://../link/61to88/7861_1.Bishttp://../link/61to88/7861_1.Bishttp://../link/61to88/8041.Bishttp://../link/61to88/8112.Bishttp://../link/61to88/8112.Bishttp://../link/61to88/8112.Bishttp://../link/89to99/9103.Bishttp://../link/89to99/9103.Bishttp://../link/89to99/9103.Bishttp://../link/12/12269.Bishttp://../link/12/12269.Bishttp://../link/12/12269.Bishttp://../link/12/12269.Bishttp://../link/89to99/9103.Bishttp://../link/61to88/8112.Bishttp://../link/61to88/8041.Bishttp://../link/61to88/7861_1.Bishttp://../link/61to88/7321.Bishttp://../link/15to30/2905.Bishttp://../link/15to30/1786.Bishttp://../link/61to88/875_3.Bishttp://../link/31to60/516.Bishttp://../link/31to60/456.Bishttp://../link/31to60/455.Bishttp://../link/31to60/432_2.Bishttp://../link/31to60/432_1.Bishttp://../link/31to60/383.Bis
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    IS 785 998

    ANNEX B

    ChairmanSHRIS. A. REDOI

    COlVMWIEE COMPOSITIONCement Matrix Products Sectional Committee, CED 53

    RepresentingGammon India Ltd. Mumbai

    MembersSHRI 0. P. AGARWAL

    SHRIJ. L. DHINGRA ( Alternate )SHRI M. A. Area

    SHRI F? D. GAIKAWAD Alternate )SHRI G. R. BHARRK AR

    COL (RETD) D. V. PADSAL,GIKAR Alternate )SHRI A. K. CHADHA

    SHRI . R. SIL Alternate )CHIEPENGINEERDEPUTYHI EP ENGI NFZR Al ternate )SHRI K. H. GANGWAL

    SHRIV. P ATTABHI ( Alternate )SHRI S. HARI RAMASAMYJ OINTDIRECTORSTANDARDS B S) CB-II

    ASSISTANTDESIGN ENGINFXR CS-I) Alternate )SHRI P. S. KAL ANI

    SHRI N. KI SHAN REDDY (Alternate )SHRI D. K . K ANUNG~

    SHRI T CHOUDHURYAlternate )SHRI P. D. KF LK AR

    SHRI P. R C. NAI R (Alternate )SHRI A. K. MANIDR I RSAD MASSED

    SHRI S. F? TF,HRI Alternate )SHRI B. V. B. PAI

    SHRI M. G. DAN~WATE Alternate )DR C. RAJ KUMAR

    SHRI H. K. J ULKA ( Alternate )SHRI S. P. RA~TOGISHRI P. S. ROY

    DR A. S. GOYAL Alternate )SHRI G. S. SHI RLKAR

    SHRI A.V. GOGTE (Alternate )SHRI K. SRIVASTAVASHRI R. SUBRAMANIAM

    SHRI K. P. ABRAHAM Alternate )SHRI C. H. SUBRAMANI AN

    SHRI A. DWTA ( Alternate )SHRI VINOD K UMAR,

    Director ( Civ Engg )

    Municipal Corporation of Delhi, DelhiRural Electrification Corporation Ltd, New DelhiB. G. Shirke Construction Technology Pvt Ltd, PuneHindustan Prefab Ltd, New Delhi

    Municipal Corporation of Greater Mumbai. MumbaiHyderabad Industries Ltd, SanatnagarTamil Nadu Water Supply and Drainage Board, ChennaiResearch, Designs and Standards Organization, LucknowAll India Small Scale A. C. Pressure Pipes Manufacturers

    Association, HyderabadNationalTest House, CalcuttaIndian Hume Pipe Co Ltd, MumbarStructural Engineering Research Centre, ChennaiCentral Building Research Institute, RoorkeeAssociated Cement Companies Ltd, ThaneNational Council for Cement and Building Materials, New DelhiFederation of UP Pipe Manufacturers, LucknowEngineer-in-Chiefs Branch, Army Headquarters, New DelhiSpun Pipes Manufacturers Association of Maharashtra (SSI).

    PuneEternit Everest Ltd, MumbaiCentral Public Works Department, New DelhiSmalI Scale Industries, New DelhiDirector General, BIS (Ex-officio Member)

    Member-SecretarySHRIJ. K. PRASAD

    Additional Director ( Civ Engg ), BISContinued on page 7 )

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    IS 783 : 1998Continued from page 6 )

    ConvenerDR N. RACHVENDRA

    Members

    Concrete Poles Subcommittee, CED 53 : 4Representing

    National Council for Cement and Building Materials, New Delhr

    SHRI . L BANDYOPADHYAYSHRI V. V. SURYA RAO ( Alternate )

    SHRI S. N. BASUSHRI S. M. MUNIAL ( Alternate )

    SHRI P C. CHA?TERIEEDIRECTOR

    DEPUTYDIRECTOR Alternate )SHRI G. L. DUA

    SHRI P D. GAIKWAD (Alternate )JOINTDIRECTORSTANDARDS

    DWUTY DIRECTORADE (B S) (Alternate )SHRIN G JOSHISHRIS K MAITHANI

    SHRI SUBHASHGARG (Alternate )GENERALMANAGER

    SHRIA. K. CHADH A ( AItCrnate )SHRI RAMFSH CHANDFX

    SHRI PRITAMSINGH ( Alternate )DR C. RAJ KUM AR

    SHRI H. K. J ULKA ( Alternate )SHRI C. B. RANWAL

    SHRI R. B. J OSHI Alternate )SHRI SHRIKANTSHARMA

    SHRI S. K . SHARMA (Alternate )SHRI A. V. TAUTI

    SHRI H. C. SHAH Alternate )SHRI S. I~ENAGRAJ ANSHRI LAKSHMINARASIMHAN Alternate )

    PROPP. C. VARGHFSESHRI K. GEORGE Alternate )

    DR S. VFZNKAT~~WARLU

    Indian Posts and Telegraphs Department. JabalpurDirectorate General of Supplies and Disposals, New DelhtOrissa Cement Ltd, RajgangpurCentral Electricity Authority, Rural Electrification Directorate.

    New DelhiRural Electrification Corporation Ltd, New DelhiResearch, Designs and Standards Organization, LucknowIndian Hume Pipe Co Ltd, MumbaiEngineer-in Chiefs Branch, Army Headquarters, New DelhiHindustan Prefab Ltd, New DelhiDelhi Vidyut Board Undertaking, New DelhiNational Council for Cement and Building Materials. New DelhiMaharashtra State Electricity Board, MumbaiPunjab State Electricity Board, PatialaSteel Pipe and Fabrication Works, VadodaraTamilnadu State Electricity Board, ChennaiConcrete Products and Construction Compay, ChennaiStructural Engineering Research Centre, Chennai

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    Bureau of Indian StandardsBIS is a statutory institution established under the Buren11 ofIndian StandardsAct, 1986 to promote harmoniousdevelopment of the activities of standardization. marking and quality certification of goods and attending toconnected matters in the country.CopyrightBIS has the copyright of all its publications. No part of these publications may be reproduced in any form withoutthe prior permission in writing of BIS. This does not preclude the free use, in the course of implementing thestandard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating tocopyright be addressed to the Director (Publications), BIS.Review of Indian StandardsAmendments are issued to standards as the need arises on the basis of comments. Standards are also reviewedperiodically; a standard along with amendments is reaffirmed when such review indicates that no changes areneeded; if the review indicates that changes are needed. it is taken up for revision. Users of Indian Standardsshould ascertain that they are in possession of the latest amendments or edition by referring to the latest issueof BIS Handbook and Standards : Monthly Additions.This Indian Standard has been developed from Dot : No. CED 53 ( 485 1 ).

    Amendments Issued Since PublicationAmend No. Date of Issue Text Affected

    -

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