BALLAST-spec-Nov 2014.ppt

ballast

1. 6 April 2023 1
BALLAST
IRS GE –1 JUNE 2004

2. 2
S. K. GARG Sr. Prof. (WORKS)
IRSE 1987 EXAM BATCH
Worked in Central Railways 1989 to 2008
Asst. Engineer at Wardha in Nagpur Division
Divisional Engr(N) in Solapur Division
Senior Divional Engineer(Co) in Mumbai Div
Dy Chief Engr in MTP and at Panvel in
Mumbai area
In Head quarters of Central Railways at CSTM

3. 5
Important Functions of Ballast
Resist vertical, lateral and longitudinal forces
Provide resilience and absorb energy
Reduce formation pressure
Facilitate track geometry correction
Facilitate track drainage
Provide voids

4. 6
Additional Functions of Ballast
Inhibit vegetation growth
Absorb airborne noise
Provide adequate electrical resistance

5. 8
Requirements of Track Ballast
Tough and wear resistant
Hard without getting crushed under moving loads
Generally cubical having sharp edge
Non-porous and non-absorbent of water

6. 9
Requirements of Track Ballast
Resist Attrition
Durable and should not get pulverized under
weather condition
Good drainage of water
Economical in cost

7. 10
Ballast may be subdivided into following
zones:
1.Crib
2.Shoulder
3.Top Ballast
4.Bottom Ballast
Track Ballast

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9. 12

10. 13
Flakiness Index
The flakiness index of an aggregate is
the percentage by weight of particles in
it whose least dimension (thickness) is
less than three-fifths(60%) of their mean
dimension

11. 14
Elongation Index
The elongation index of an aggregate is the
percentage by weight of particles in it whose
greatest dimension (length) is greater than
one and four-fifth times (1.8 times) their mean
dimension

12. 15
Ballast Fouling
Potential sources are
Ballast breakdown
1.Handling
2.Tamping/packing
3.Traffic
4.Weathering
CONTD..

13. 16
Fines from subgrade
1.Mud pumping
2.Seepage
Fines from surface
1.Droppings from trains
2.Wind or water transported
Ballast Fouling

14. 17
Effects of Fouling
Impedes drainage
Affects elasticity of ballast
Tamping/ packing becomes difficult
Increases dynamic loads
Reduces electrical resistance

15. 18
Remedial measures -fouling
Shoulder screening :Preventive maintenance –
Once in 3 yrs.
Deep Screening :Breakdown maintenance –
Once in 10 yrs.
DeepScreeningoftrackshallbedoneafter
500GMTor10years,whicheverisearlier,orif
cleancushionislessthan150mm.(ACS132)

16. Physical
parameters
General
Requirement
Functional Requirement
i) Specific
Gravity
Moremass More mass helps in resisting
lateral forces.
ii)StructureCubical shape i.For compaction & internal
friction
ii.Round ballast cannot be
compacted
iii.Helps enhanced retentivity
a)Shape
b)GradingUniformly gradedi) Optimum voids for resilience and
drainage
ii) Longevity is controlled by the
voids available to accommodate
fines.
Parameters for determination of
Standard of Ballast
CONTD..

17. 21
Mechanical parameters
i)Hardness Resistance to abrasion/attrition, required
for least damage / breakage during
maintenance. This is measured by Los
Angels Abrasion value.
ii)Toughness Resistance to fracture under impact
loads. This is measured by Impact Value.
iii)Water
absorption
This should be checked to ensure higher
resistance to weathering during adverse
weather conditions.
Parameters for determination of
Standard of Ballast
CONTD..

18. 22
Chemical parameters:
i)Inertness This should be checked to ensure that
ballast is chemically inert and inactive
from decomposition.
Parameters for determination of
Standard of Ballast

19. 23
DETAILED SPECIFICATIONS
IRS GE –1 JUNE 2004
BasicQuality:Ballastshouldbehard,durable
andasfaraspossibleangularalong
edges/corners,freefromweatheredportionsof
parentrock,organicimpuritiesandinorganic
residues.
ParticleShape:Ballastshouldbecubicalin
shapeasfaraspossible.Individualpieces
shouldnotbeflakyandshouldhavegenerally
flatfaceswithnotmorethantworounded/sub
roundedfaces.

20. 24
ModeofManufacture:
1.AllBGmainlinesandrunninglines,excepton‘E’
routesbutincluding‘E’specialroutes:machine
crushed
2.Other BG linesand MG/NG routes
planned/sanctionedforconversion:preferably
machinecrushed.Handbrokenballastcanbe
usedinexceptionalcaseswithpriorapprovalof
ChiefTrackEngineer/CAO/C.
3.OtherMG&NGroutesnotplanned/sanctionedfor
conversion:handbrokenballast,noapprovalshall
berequired.
DETAILED SPECIFICATIONS

21. 25
Physical Properties
Ballast sample should satisfy the following physical
properties in accordance with IS:2386 Pt.IV-1963 when
tested as per the procedure given in Annexure 1&2
BG, MG & NG
(Planned/sanctioned
for conversion)
NG&MG(Other than
those planned for
conversion)
Aggregate
abrasion value
30% Max* 35% Max
Aggregate
Impact Value
20% Max* 30% Max
DETAILED SPECIFICATIONS
CONTD..

22. 26
*Inexceptionalcases,ontechnicaland/or
economicgroundsrelaxableupto35%&25%
respectivelybyCTEinopenlineandCAO/C
forconstructionprojects.Therelaxationin
AbrasionandImpactValuesshallbegiven
priortoinvitationoftenderandshouldbe
incorporatedinthetenderdocument.
DETAILED SPECIFICATIONS

23. 27
The “Water Absorption” tested as per IS:2386
Pt-III –1963 following the procedure given in
Annexure 3 should not be more than 1%. This
test however, to be prescribed at the
discretion of CE/CTE in open line and
CAO/Con for construction projects.
As per correction slip No 3 a new para 2.2.2.1
is added. Now CAO/CTE can permit relaxation
upto 2.5% in water absorption for specified
areas
DETAILED SPECIFICATIONS

24. 28
•SIZE AND GRADATION: FULL RATE
PAYMENT
Retainedon65mmsq.meshsieve-5%Maximum
Retained40mmsq.meshsieve
Formachinecrushedballast:40%to60%
Forhandbrokenballast:Notrequired,butthe
executivemustensurethattheballastiswellgraded
between65mmand20mmsieve.
Retainedon20mmsq.meshsieve
Notlessthan98%formachinecrushed
Notlessthan95%forhandbroken
DETAILED SPECIFICATIONS

25. 29
OVERSIZE BALLAST-Reduced Rate
Payments
i)Retentionon65mmsquaremesh
sieve
AMaximumof5%ballastretainedon65mm
sieveshallbeallowedwithoutdeductionin
payment.
Incaseballastretainedon65mmsieve
exceeds5%butdoesnotexceed10%,
paymentat5%reductionincontractedrate
shallbemadeforthefullstack.
DETAILED SPECIFICATIONS

26. 30
•Ifballastretainedon40mmsquaremeshsieve
(machinecrushedcaseonly)>60%,paymentatthe
reducedratesshallbemadeforthefullstackin
additiontothereductionworkedoutabove.
•5%reductionincontractedratesifretention
on40mmsq.meshsieveisbetween60%
(excluding)and65%(including)
•10%reductionincontractedratesifretention
on40mmsq.meshsieveisbetween65%
(excluding)and70%(including).
DETAILED SPECIFICATIONS
OVERSIZE BALLAST-Reduced Rate
Payments

27. 31
OVERSIZE:
Whentheballastretainedon65mmsieve>10%.
Whentheballastretainedon40mmsieve>70%.
UNDERSIZE:
Whentheballastretainedon40mmsieve<40%.
MachineCrushedBallast:Whentheballastretainedon20
mmsieve<98%.
HandBrokenBallast:Whentheballastretainedon20mm
sieve<95%.
DETAILED SPECIFICATIONS
REJECTION OF BALLAST ON GRADATION
ACCOUNT

28. 32
METHOD OF SIEVE ANALYSIS
•Sievesizesarenominalsizes.
•Thefollowingtolerancesshallbepermitted:
65mmsquaremeshsieveplusminus1.5mm
40mmSquareMeshSievePlusMinus1.5mm
20mmSquareMeshSievePlusMinus1.0mm
•Meshsizeofthesievesshouldbecheckedbeforeactual
measurement.
•Thescreenshallnotbelessthan100cminlength,70cmin
breadthand10cminheightonsides.
DETAILED SPECIFICATIONS

29. 33
METHOD OF SIEVE ANALYSIS
•While carrying out sieve analysis, the screen shall not be
kept inclined, but held horizontally and shaken vigorously.
•The pieces of ballast retained on the screen can be turned
with hand to see if they pass through but should not be
pushed through the sieve.
•The percentage passing through or retained on the sieve
shall be determined by weight.
DETAILED SPECIFICATIONS

30. 34
CONDITIONS FOR SUBMISSION OF
TENDER
Eachtendereratthetimeoftenderingshallsubmit
thetestreportofImpactValue,“AbrasionValue,
WaterAbsorptionValuefromapproved
laboratoriesandthelistoftheseLaboratoriesshall
bementionedinthetenderdocuments.
Thetenderershallalsofurnishanundertakingas
incorporatedinthetenderdocumentthattheballast
supplyatalltimeswillconformtoSpecificationsfor
TrackBallastasspecifiedbyRailway.
DETAILED SPECIFICATIONS

31. 35
STACK MEASUREMENT
Stackingonaneat,plain,firmandwelldrainedground
Theheightofstackshallnotbelessthan1m(hillyareas-
0.5m)butnotmorethan2.0m.
Topwidthshallnotbelessthan1m.
Topofstackshallbekeptparalleltothegroundplane.
Thesideslopesshouldnotbeflatterthan1.5:1(H:V).
Cubicalcontentofeachstackshallnormallybenotless
than30cuminplainareasand15cuminhillyareas.
DETAILED SPECIFICATIONS

32. 36
WAGON MEASUREMENT
Acontinuouswhitelineshouldbepaintedinsidethe
wagon
Thecubicalcontentincubicmetercorrespondingto
whitelineshouldalsobepaintedonbothsides
outsidethewagon.
Inaddition,shortpiecesofflatswithcubical
contentspunchedshallbeweldedatthecentreof
allthefoursidesaspermanentreference.
Incasethesupplyistakeningeneralservice
wagons,actualmeasurementswillbetaken.
DETAILED SPECIFICATIONS

33. 37
SHRINKAGE ALLOWANCE
Paymentshallbemadeforthegross
measurementseitherinstacksorinwagons
withoutanydeductionforshrinkage/voids.
Whenballastsupplyistakeninwagons,
shrinkageupto8%shallbepermittedat
destinationwhileverifyingthebooked
quantitiesbytheconsignee.
DETAILED SPECIFICATIONS

34. 38
SAMPLING AND TESTING
Aminimumof3samplesofballastforsieve
analysisshallbetakenformeasurementdoneon
anyparticulardateevenifthenumbersofstackstobe
measuredarelessthanthree.
Thetestviz.,determinationofAbrasionValue,Impact
ValueandWaterAbsorptionshouldbegotdone
throughapprovedlaboratoriesorRailway’sown
laboratories(Listoftheselaboratoriesshallbe
mentionedinthetenderdocument).
DETAILED SPECIFICATIONS

35. 39
Normstobefollowedinrespectofsampling,testingand
acceptance:
Onsupplyofthefirst100cum,thetestsforsizegradation,
Abrasionvalue,Impactvalueandwaterabsorption(if
prescribed)shallbecarriedoutbyRailways.
Furthersupplyshallbeacceptedonlyafterthisballastsatisfiesthe
specificationsforthesetests.
RailwayreservestherighttoterminatethecontractasperGCCat
thisstageitselfincasetheballastsupplyfailstoconformwithany
ofthesespecifications.
DETAILED SPECIFICATIONS
CONTD..
SAMPLING AND TESTING

36. 40
Subsequent tests :
Supply in stack
Supply in
wagons
For stack of
volume less than
100cum
For stack volume
more than
100cum
a) Size and
Gradation Tests
-No of Tests One for each stack
One for each
stack
One for each
wagon
-Size of one sample** 0.027 cum
** 0.027 cum for
every 100cum or
part thereof
** 0.027 cum
b) Abrasion Value
Impact Value &
Water
Absorption test @
One test for every 2000 cum
DETAILED SPECIFICATIONS
CONTD..

37. 41
**Sampleshouldbecollectedusingawoodenbox
0.3mx0.3mx0.3mfromdifferentpartsofthe
stack/wagon.
@Thesetestsshallbedoneforthepurposeofmonitoring
qualityduringsupply–furthersupplycanbesuspendedin
caseofnon-conformation.
•Theabovetestsmaybecarriedoutmorefrequently,if
warrantedatthediscretionofRailway
AlltestsforabrasionvalueImpactvalueandwater
absorptionconductedsubsequentlytoawardofcontract
shallbedoneatRailways’cost.
DETAILED SPECIFICATIONS

38. 42
IRPWM PROVISIONS REGARDING
BALLAST
PARAS 261 TO 271 IN IRPWM
PARA 263: PROFILE OF BALLAST
PARA 270 OF IRPWM: SURPLUS BALLAST IN
TRACK SHALL BE COLLECTED AND STACKED
IN REGULAR HEAPS.
PARA 264-267 MODIFIED VIDE RAILWAY
BOARD’S LETTER No. 2006/CE –II/MB/2 Dt.
25.05.07

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