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I ndian St andardIS : ; 988

GENERALREQUIREMENTSFORVIBRATORSFORMASSCONCRETING,IMMERSIONTYPE

UQC 6669703316

BUREAU OF INDIAN SIANDAKIJSMANAK BHAVAN, 9 BAHAIIUR SHAH ZAFAK MARG

NEW DELHI 110002

( Reaffirmed 1995 )

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IS : 12468 - 1988

Zndian St andardGENERALREQUIREMENTSFORVIBRATORSFORMASSCONCRETING,

IMMERSIONTYPE0. FOR

0.1 This Indian Standard was adopted by theBureau of Indian Standards on 29 July 1988,after the draft finalized by the Construction Plantand Machinery Sectional Committee had beenapproved by the Civil Engineering DivisionCouncil.0.2 The compaction of concrete by vibration hasrevolutionized the concept of concrete technology,making possible USC of low slump stiff mixes forproduction of high quality concrete with requireddegree of strength, density, durability and im-permeability. lmmersion vibrators are mostcommonly used for compaction of plain andreinforced concrete. With the introduction ofcentralized batching plant and mass concretingtechniques, compaction of concreting by vibrationby immersion vibrator up to 90 mm diameter hasbeen found to be inadequate especially whiletaking into account the speed of pouring of con-crete. In mass concreting, aggregates of size upto 150 mm is used. Effective compaction cannotbe obtained with smaller diameter needles and assuch it has become necessary to use bigger dia-meter needles. This standard is being preparedfor giving guidance in the manufacture and useof immersion vibrators of needles of diameter

EWORDover 90 mm. Immersionvibrators of 90 mm andbelow have already been covered in 1s : 2505-1988*.0.3 Pneumatic and electrically driven motor inhead type immersion vibrators are to be advan-tageous for higher diameter immersion vibrators.Use of petrol/diesel engine prime mover has beenfound to be unsatisfactory in view of the weightdue to higher horse power rating of the unit. Forsafety reasons, use of high frequency, low voltageelectrical drive units are recommended for thesevibrators.0.4 For the purpose of deciding whether a parti-cular requirement of this standard is compliedwith, the final value, observed or calculated, ex-pressing the result of a test or analysis, shall berounded off in accordance with IS : 2- I960t. Thenumber of significant places retained in therounded off value should be the same as that ofthe specified value in this standard.

*General requirements for concrete vibrators, immer-sion type ( fhir d revi sion ).TRules for rounding off numerical values ( revLed ).

1. SCOPE1.1 This standard lays down requirements formaterial, size, construction and performance ofimmersion vibrators above 90 mm size.2. TERMINOLOGY2.0 For the purpose of this standard, the defini-tions given in IS : 2505-1988* and the followingshall apply.2.1 Driving Shaft - A shaft which connects themotor and the eccentric shaft, and gives the driveto the eccentric shaft.2.2 Driving Gear - A gear on the motor out-put shaft and the eccentric shaft.

*Gc:neral requirements for concrete vibrators, irnmer-sion type ( fhird revision ).

2.3 Spindle Coupling - Couplingnects the eccentric shaft and thethrough the spindle tube.2.4 Spindle Tube ~ A tube whichdrive shaft.2.5 Upper Eccentric Housingwhich is on the driving end of theconnected to the spindle tube.3. MATERIALS3.1 The tube of the vibrating

which con-motor gears

encloses theCap - Capvibrator and

ncedle shallbe seamless steel tube or heavy clash EKWtube conforming to IS : Il61-1979* or IS : 1239( Part 1 )-19791.*Specification for steel tub.? for strucrur,~l I~LII~~IXS

( r/& d reuisiorr ).TSpecification for mild steel tubes, tubulars and otherwrought steel fittings: Part 1 Mild steel tubes ( ~CJUIY/~revision ).

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IS : 12468 - 19883.2 The bottom cap shall be of carbon steel ofgrade 35C8 of IS : 1570 ( Part 2 j-1979 and shallbe tempered and hardened to 40 to 50 HRC orcast steel conforming to grade 1 of 1s : 1030-1982-f.3.3 The eccentric shaft/rotor shall be made ofcarbon steel of grade 35C8 of IS : 1570 ( Part 2 )-1979* and shall be tempered.3.4 Bearings - The bearings shall bc cf ballbearing type of suitable capacity and conformingto relevant Indian Standards.3.5 Drive Shaft -.- The drive shaft shall beseamless tube with end coupling of carbon steelwith internal gear teeth for coupling to the eccen-tric shaft end and motor end.3.6 Handle - It shall be of mild steel withrubber covering to suit the site requirements.4. SIZES4.1 The size of the vibrator shall be denoted bythe outside diameter of the vibrating needle andexpressed in mm.

4.1.1 The actual outside diameter of the needlemeasured anywhere in its length excluding thebottom ctp and the top tube shall not differ fromthe outside diameter by more than f2 mm.4.1.2 The standard outside diameter of the

vibrating needle shall be 100, 110 and 150 mm.4.1.3 Length of Vibrat ing Nw dlc~ - The lengthof vibrating needle shall be measured from theouter end of the bottom cap to the joint between

-*Schedules for wrought steels for general engineeringpurposes: Part 2 Carbon steels ( unalloyed steels ) (finer

revisiott ).@pccification for carbon steel castings for generalengineering purposes ( thi rd revision ).

the needle casing and the upper eccentric housing.Tolerance of the length shall be & 5 mm.NOTE The following standard lengths are recom-mended for selection of suitable length depending uponthe nature of jobs required. These sizes have beenrecommended arbitrarily, purely with a view to aidingrationalized production by limiting a number of sizesof 600,625 and 650 mm.

5. CONSTRUCTION5.1 Vibrating Needle

5.1.1 Tube - The tube should be reinforcedat the threaded portion as indicated in Fig. I toprevent any failure due to lesser thickness at thispoint. Suitable bearing blocks have to be weldedinside the tube for mounting the bearings of theeccentric shaft. This is necessary because theouter diameter of the bearings of the requiredcapacity may be less than the inside diameter ofthe needle casing ( ,seeFig. 1 ).5.1.2 Bearings - These shall be of adequatesize, and suitably mounted and press fitted on theshaft so as to take both radial and axial loads.The bearings and the eccentric shaft assemblyshall be such as to enable the removal of shaft forrepairs and replacement.5.1.3 Concentricify - The eccentric shaft or

rotor upon assembly shall be such that all com-ponents are concentric about their respectivecentre lines where bearing, journals, housing anddrive shaft, etc, are concerned.5.1.4 Vibrating Needle - It shall be completelysealed against entry of moisture, dust, grout, etc.

6. PERFORMANCE REQUIREMENTS6.1 It shall be in accordance with IS : 25OS-1988*

*General requirements for cuncrcfe vibrators, immer-sion type ( flrird revision 1.

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BUREAU OF INDIAN STANDARDSHeadquarters:Manak Bhavan, 9 Bahadur Shah Zafar Marg, NEW DELHI 110002Tel ephones: 331 01 31, 331 13 75

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