bila spur report final

8/12/2019 Bila Spur Report Final

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Pavement design of Heavy duty pavement of coal haul road in coalmines area Gevra Bilaspur

General: India is rich in natural resources and these resources are both superficial andunderneath the earth. While forest are the main superficial assets, minerals fuels

and precious metals constitute the assets underground. All these resources areuseful in building our life and hence continued efforts are being made to explore,extract and utilize these resources to a greater extent.

The fuel resources are of great importance as these help in extracting the potencyof other resources. Also there are vital re uisites industry, transport and po!ersectors. With this importance all the forms of fuels have commercial value, be itsolid "coal#, li uid "petroleum# and gas "natural gas methane#. It is for this reasonmining for these resources has been a ma$or activity at these region !here they areabundantly available. %any of the Indian states are the hubs of mining of coal,petroleum and gas. &har'hand, parts of (.). *rissa, +hattisgarh, and %adhya

)radesh are the production centers of coal.

Gevra cola mines area near ilaspur in %adhya )radesh is controlled andmanaged by -outh astern +oal /ields "- +0#. It is a ma$or coal production minebeing explored for huge uantities of coal in near future. The mining activitiesre uire a good road net!or' !ith satisfactory service to facilitate smooth movementof mining machines, dozers, excavators, haul truc's etc.

This is essential to maximise the production !ith increased efficiency in handlingthe activities. 1aul roads used for carrying overburden materials and coal transportroads need a uplift.

The Gevra mine area is comprised of t!o mining fields 2 Gevra and 3ipi'a. WhileGevra area has got a haul road, 3ipi'a is yet to get this road, for !hich the planninghas been made. The condition of the existing haul road and coal transport road isalso not good. -ince the - +0 is proposing to ac uire a fleet of hauling truc's of456 tonnes capacity, it is imminent to complete and upgrade the road net!or' tomeet the re uirement. It is !ith this bac'ground, - +0 had re uested +77I tocarryout the re uired studies and ma'e recommendations for the design of ne!road and betterment of existing haul road !ide their letter no.G%"4#8- +08 -)8466984494 dated ;64;69. The details of the coal field in bothGevra and 3ip'a area and road net!or' is sho!n in /igure and 4, respectively.

1.2 Objectives and Scope

The main ob$ective of the study is to design haul roads for these areas and ma'erecommendations. Thus, the scope included the follo!ing :

i# A preliminary site visit and discussions

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ig 1! layout "ap of road net#or$ in Gevra coalmines area

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ig 2! layout "ap of road net#or$ in %ip$a coalmines area

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ii# /ield studies and sample collectioniii# 0aboratory evaluation of material samplesiv# Analysis of data and interpretationsv# 7eport !ith recommendations

1.& '(isting )oad *et#or$

The 3ip'a area has to develop the haul road, but the Gevra area has got a haulroad, !hich needs to be extended and improved. Thus both need a proper designand construction. In addition the existing coal transport road is poor in conditionand needs to be structurally and functionally upgraded. Thus, the study needed afocus on evaluation of subgrade soil8existing earth and available road buildingmaterials.

The existing haul road also has been made up of only layers of earth and stoneboulders added at different times. 3ue to heavy vehicle movement, the structure

gets affected repeatedly and this accumulated damage has rendered the road verypoor to meet the re uirements. The coal transport road !ith heavy and continuoustruc' traffic is also damaged by repeated loads and !ater that is being continuouslysprin'led to arrest the coal dust. It is therefore, immediately re uired to design,construct and improve these roads accordingly.

2. +',% +*-'S +G/ +O*S2.1 General

A field visit !as made to assess the situation by !ay of discussions !ith theconcerned officials of - +0 and visual inspection of existing condition. Test pits!ere cut and field density of granular layer and subgrade !ere ta'en. collection of

samples of materials !ere done .A number of field tests and surveys !ereunderta'en !ith a vie! to evaluate the present condition of roads and to determinethe uality of road construction materials used in construction of various pavementslayers, !hich included bituminous, granular and sub;grade. The field investigations!ere done to determine the structural ade uacy of the existing pavement, to findout the nature and extent of distress and to recommend appropriate measures forits rehabilitation. The various field studies that !ere underta'en during the courseof field visits are:

)avement condition assessment Test pit observations

Traffic volume studyThe detailed methodology adopted for carrying out the above activities in the field ispresented in the follo!ing sub;sections.

2.2 Soil Sample 0ollection-amples of the existing soil and fill material !ere collected from the site to betested for the follo!ing properties:

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i. Atterberg; ? sho! vie! of test pit cutting in progress. 0ocation of test pit and density

measurements are given in Table

0ocation @ear !eigh

bridge in

3ip'a area

@ear border of

old 3ip'a and

Gevra

+orner of

+entral

7amp

+orner of ne!

approach haul

road

+oal

transport

road

&unction of

central and

south ramp)it no. 4 = 9 5/ield density 4.499 4. 99 +ould notdone

+ould notdone . >

+ould notdone

/ield

%oisturecontent

B.9 4.6 >.6

/ield dry

density4.69B .B4 .4?

2. raffic -olume and %ata

The haul road net!or' is expected to cater for routine traffic in addition to movementof 456 T capacity dumpers under the *perational areas for = ?66 repetitions peryear. The dumpers carrying coal generally move on the roads indicated in the layoutmay. The daily traffic of these dumpers are 46 vehicles per day and their payloadis generally in the range of 4=6 tons to 456 tons.

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ig 1 ! -ie# of 0oal "ines

Photo 1 -ie# of open cast mines

Photo 2 /nother vie# of open cast mines

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ig & General vie# of the Haul )oad

ig ! General -ie# of the Haul )oad

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ig -ie# of 123 t %umper

ig 4 ransportation of 0oal in progress

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ig 5 "ovement of 0oal Hauler along the e(isting blac$topped road

ig 6 Proposed /lignment of ne# road in front of #or$shop #ith appearanceof crac$s on e(isting shale material

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ig 7 0ondition of e(isting 0oal Haul road

ig 13 / vie# of overburden haul road in Gevra area

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ig 11 Surface condition of coal haul road

ig 12 Surface condition at starting point of coal haul road

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ig 1& %istressed locations on haul road

ig 1 0ondition of turning areas of haul road

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ig 1 ailure due to poor drainage condition and lac$ of proper0amber

ig 14 %evelopment of Potholes due to inade8uate maintenance and poordrainage

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ig 15 -ie# of pit cutting in progress on overburden haul road

ig 16 est pit cutting on haul road

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&.3 ,/BO)/ O)9 'S +*G /*% /*/,9S+S

&.1 General

The laboratory investigations are carried out primarily for assessment of overallconstruction uality. 0aboratory evaluation of uality of materials collected from

various test pits, includes mechanical and engineering characteristics. In order toevaluate different characteristics of various road building materials used duringconstruction of study stretches a number of relevant tests on subgrade soils,aggregates, !ere carried out. 0ocation of test pits dug on different road stretches!ith details of samples collected from each test pit for detailed laboratory evaluationin Institute


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0ocationof soil

sample

- a n d

+ o n

t e n

t

" ) e r c e n

t # 0 i u i d 0 i m i t

" ) e r c e n

t # ) l a s t

i c l i m i t

" ) e r c e n

t # ) l a s t

i c i t y I n d e x

" ) e r c e n

t #

*

% +

" ) e r c e n

t #

% o

d i f i e

d ) r o c t o r

3 e n s i

t y

" g m

8 c c #

+ a

l i f o r n

i a

, e a r i n g

7 a

t i o

" C #

- a t u r a

t i o n

% o

i s t u r e

" C #

3ip'axtn )it 4 = 45.5 >.5 B B.9 .?>= 4.5 63ip'a

xtn )it ? 4>. 5.6 6.5 .?45 =.? 6.5

Table 2 Test 7esults of %oorum, -hale D 3ebris -amples

Type ofsample -

a n

d +

o n

t e n

t

" ) e r c e n

t # 0 i u i d

0 i m i t

" ) e r c e n

t # ) l a s t

i c l i m i t

" ) e r c e n

t # ) l a s t

i c i t y I n d e x

" ) e r c e n

t #

* %

+

" ) e r c e n

t #

% o

d i f i e

d ) r o c t o r

3 e n s i

t y

" g m

8 c c #

+ a

l i f o r n

i a

, e a r i n g

7 a

t i o

" C #

- a

t u r a

t i o n

% o

i s t u r e

" C #

Gevramoorum 55 46 ; @) B 4. 95

B.> 4.5

+rushed-hale 9> 4 ; @) ?.9 4.6B4 9.= .4+oal

debris"Gevra#

5> 4? ; @) .> > 4 5

Table 2= Test 7esults of Aggregate -amples

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-ource of aggregate sample Aggregate-ample

Agg ImpactEalue C

Water Absorption

C

WetImpact

Ealue C7atanpur aggregate 4 6.>9 9+ho!daha aggregate 4 4> .9= 4

%a'hanpur aggregate = 9.9 5

able ! est results of 0oarse Sand for %rainage ,ayer

Sieve Si;e Percent passing=.>9 mm B94.6 mm B

.6 mm ??>9 micron =

4.3. Pavement %esign

/or handling of coal and overburden material, use of heavy dumpers is essential.

+onse uently for operation of such dumpers, it is necessary to design appropriate

pavement systems other!ise there is a possibility of undesirably large settlement

under the !or'ing loads.

/or the safe !or'ing of a dumper, the pavement thic'ness should be ade uate for

the magnitudes of imposed load and the sub;grade soil support should be ade uate

to prevent excessive settlement. The pavement should be constructed !ith properspecifications ensuring ade uate uality control.

The relationship curves for flexible pavement thic'ness vs. +. .7. of sub;grade soil

had been !or'ed out, for a 456 t )ayload +apacity dumper !hich is expected to

operate !ithin the coal mine.

4.1 Parameters for %evelopment of le(ible Pavement %esign < hic$ness -s.

0.B.). )elationship= for 243 t Payload 0apacity %umper

The 456 %T )ayload +apacity dumper consists of pneumatic tyres carrying

45B,?= t on the rear axle and =,5B= t on the front axle and a tyre pressure of

.4 'g8 cm 4 "/igure #. /or 6 9 repetitions of the !heel load the load repetition

factor is 6.?. The design of flexible pavement consists essentially of t!o steps:

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"i# 3evelopment of relationship bet!een e uivalent single !heel load " -W0#

and depth of construction for different values of +. .7. "/igure =#

"ii# 3evelopment of + 7 +urves for 3esign of /lexible )avement for 456 t

)ayload +apacity 3umper. "/igure 9#.

"iii# The thic'ness of pavement crust for different values of + 7 are indicated in

Table >.

4.2 Parameters for %evelopment of le(ible Pavement %esign for 0oal

ransportation road

Traffic volume data !as collected by covering all categories of vehicles includingnon;motorized traffic at one location. The data !as collected by employing trainedfield personnel !ho recorded counts in a prescribed proforma. The traffic volume

surveys !ere carried out for 4= hours continuously in three shift.

The survey covered counting of different category of vehicles viz., light vehicles and

commercial vehicles li'e truc's, buses, 0+E "goods# etc. The location of traffic

count points !as near old #or$shop on coal transportation road . The data on

classified volume counts, for both directions of traffic, is given in Table 5

Table 5 +lassified volume counts on coal transportation roadEehicle Type -hift -hift 4 -hift Total

T!o !heeler 6>4 564 =54 4 5&eep8Tempo B= 4 5 4 >

Truc' single Axles =6> 46 4B9 B69

Truc' Tandem Axles 566 6B 5? = B6

Truc' Three Axles =6 ? =9 >>5

Tan'er 4? tonne 59 9? B> 446Truc' 9 Axles ?5 5? == 5B?+rane B ? =6Grader 49 = 5 93ozer B 5 5

46 ton 3umper 6 9 >9 =6

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)ro$ected 3esign Traffic 0oading in Terms of +umulative -tandard Axles

/or design purposes, variation in axle loads is usually handled by converting8reducing the actual axle load to an F uivalent -tandard Axle 0oad " -A0# . An

e uivalency is simply a convenient means for indexing the !ide spectrum of actualloads to one selected value, !hich is ?.4 tonnes for single axle load and 9.tonnes for tandem axle "? tyres# load. The relative damaging effect of different axleloads is determined based on a characteristic relationship termed as the F/ourth)o!er 0a! . The rule states that the damaging po!er of an axle load increasesroughly as the fourth po!er !ith the increasing !eight of the axle. Any single axleload less than ?466 'g is therefore some fraction of e uivalent single axle load" -A0#, !hereas a load greater than single axle load is some multiple of -A0.-imilarly for tandem axles !ith ? tyres assembly, the rule states that the damagingpo!er of tandem axle increases as the fourth po!er !ith regard to the !eight of thestandard tandem axle, !hich is 9. tonnes.

The design traffic in terms of +umulative -tandard Axles is !or'ed out by

considering the heavy commercial traffic and their damaging effects"E3/# as

explained in the earlier section, for a convenient design life duly accounting for the

anticipated traffic gro!th. In the present case, the cumulative standard axles are

!or'ed out for 6 years design life, assuming an annual gro!th rate of >.9C per

year.

@s H / r

@s: The cumulative number of standard axles to be catered for in the design A: Initial traffic, in the year of completion of construction, in terms of the

number of commercial vehicles per day duly modified to account for lane

distribution.r: Annual gro!th rate of commercial vehiclesx: 3esign life in years/: Eehicle damage factor

%esign of 0oal Haul )oad+ 7H43esign trafficH 5B?B +E)3

59 x A J" Kr#x 2 L

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E3/H =.93esign 0ife H 6 years0ane distribution factor H6.>9Total Traffic H 6? %-A)avement thic'nessH B56 mm

xisting +rust H 566 mm*verlay re uired H 56 mm "detail is given in table of 7ecommendation#

The value of cumulative standard axles covering different categories of commercial

vehicles is pro$ected to be about 6? million standard axles, over a rehabilitation

design life of 6 years

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/ig . 3imensions of 456 t )ayload +apacity 3umper

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3

3333

133333

1 3333

233333

2 3333

3 3 133 1 3 233 2 3 &33 & 3 33

%epth of 0onstruction> cm

' 8 u i v a l e n t S i n g l e ? h e e l , o a d

> $ g

0B) 2

0B) &0B)

0B) 0B) 4

0B) 5

0B) 60B) 13

/

B

igure ! )elationship bet#een 'S?, and %epth of 0onstruction for 243 tPayload 0apacity %umper

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3

3

133

1 3

233

2 3

2 & 4 5 6 7 130B)> Percent

% e p t h o

f 0 o n

s t r u c t i o n

> c m

igure ! 0B) 0urves for %esign of le(ible Pavement for 243 tonne %umper igure ! 0B) 0urves for %esign of le(ible Pavement for 243 t Payload

0apacity %umper

Table > : Ealues of + 7 vs 3epth of +onstruction for 456 t payload capacity dumper

+ 7 3 )T1 */ +*@-T7(+TI*@,+%

= 4 6

9 ?95 56> =6? 46B 66 66

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5.3 %iscussion of test results

ased on the observations recorded during the field visit of +oal mines in Gevra

area and subse uent testing of high!ay material such as sub grade soil,

aggregates, moorum, shale and coarse sand, interim recommendations for the

pavement design of over burden haul road and for maintenance of coal haul road

are given belo!:

. The design + 7 for design of the pavement crust shall be assumed as =.

4. The roads shall be designed on the follo!ing criteria:

i. 7oads for movement of coal dumpers

ii. 7oads for haulage of *verburden material

. +oal haul roads are badly distressed due to poor drainage. +oal dust has been

deposited at edges and shoulder portion of the pavement, !hich preventsdrainage of !ater from pavements to edges. Therefore first the coal dust should

be removed from shoulder portion and one layer of Water bound %acadam

"W %# GII as profile corrective course. The additional layers may be provide as

under.

=. The shale material " sand!iched layer bet!een overburden earth and coal#

may be used for raising emban'ment and ma'ing sub grade. This material can

not be used in sub base layer or in W % layer as a filler, being plastic in nature.It is advisable not to use this material for, maintenance of potholes or distressed

area in granular layer.

9. The overburden earth is of varying uality in nature place to place and some of

!hich can be used for preparing sub grade for overburden haul road.

5. )roper camber is re uired in all the existing roads as the existing camber is

inade uate.

>. +oal haul road is badly distressed due to poor drainage. +oal dust has been

deposited at edges and shoulder portion of the pavement, !hich prevents

drainage of !ater from pavements to edges. Therefore first the coal dust should

be removed from shoulder portion and surface profile should be corrected and

thereafter various layers should be made as given in Table belo!.

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?. Aggregates to be used in W % should have aggregates impact value less than

6. Aggregates from uerry of 7atanpur and +ho!daha may be used but

Aggregates from uerry of %a'hanpur should not be used.

B. %oorum is non plastic having )I less than 5 so it can be used in W % layer.

6.Ade uate hard shoulder of 4 meter !idth on both side is to be made. %aterial

used in shoulder should be non plastic in nature. +ross fall of percent should

be made to uic' run off of sprin'ling !ater on the pavement.

.)roper drainage along the pavement is needed to drain off !ater immediately.

4.Total road !idth of = m includes !idth of +arriage!ay 4 m, !idth of 3ozer

path 9 m, and shoulders of 4 m each on both side.

6.3 )'0O""'*%/ +O*S

6.1 General )ecommendations

. The present drainage system is inade uate and should be improved by

constructing side drains at missing locations. -houlders shall be corrected to

C camber so that the !ater drains off immediately. 3rains should be

cleared off bushes to improve the existing drain system.

4. 0ocations !here the section is badly crac'ed needs to be removed and a

fresh layer should be placed.

6.2 )ecommendations for Pavement design and rehabilitation

)ecommendations

Type of 7oad @e!8 xisting

pavement

7ecommendation

*verburden haul

road in Gevra Area

xisting

)avement

*ne layer of W % GII 66mm

*ne layer of W % GIII 66 mm*verburden haul

road in 3ipi'a Area

@e!

)avement

Total pavement thic'ness H4 66 mm

/ourteen layers of W % GII each 66 mm

T!elve layers of W % GIII each >9 m+oal Transportation

7oad in Gevra Area

xisting

)avement

one layer of % 66 mm as per %o-7T1

Grading Table 966;= "as profile corrective course#

one layer of 3 % 66 mm as per %o-7T1

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Grading Table 966; 6

one layer of 0-A%M 66 mm Grading given belo!

one layer of -3 + 96 mm

0-A%M 0arge size Aggregate %ix grading is effective as rut resistant mix

-pecified Aggregate Gradation for 0arge -ize Aggregate %ix "0-A%#

-ieve size "mm# )er cent passing=9.6 mm 66

>.9 mm B6; 6649.6 mm ?4;B6

B.6 mm 5?;B6B.9 mm ==;>4=.>9 mm 4?;944. 5 mm 46;=6

566 micron 5;4466 micron 9; 996 micron 4; 6

>9 micron 4;>

+ross section of *verburden haul road in 3ip'a area

/ppendi(@1Specification for 5 mm ?B"

/. Properties of 0oarse /ggregate

DozerPathShoul er

32 !5 !

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i. 0os Angeles Abrasion Ealue, per cent max. =6ii. Aggregate Impact value, per cent, max. 6iii. /la'iness and longation Index, combined , max. 6

B. Grading )e8uirement for 0oarse /ggregate

-ieve-ize mm

>9mm W %Grade ; II

>9mm W %Grade ; III

49 ; ;B6 66 ;5 B6; 66 669 49;>9 B9; 66=9 6; 9 59;B6

44.= 6;9 6; 6.4 6;9

0. Grading )e8uirement for Screening

-ieve-ize

mm>9mm W %

.4 ;

.4 669.5 B6; 66?6 N 9; 9

%. Auantities for 5. cm thic$ness

i. +oarse Aggregate for >.9 cm compacted thic'ness per 6 m 4 H 6.B 2 .6>m

ii. -tone screening type for 6.4 ; 6.44 m for GII and 6. ? ; 6.4 m for GIII

iii. inding material of plasticity index less than 5C H 6.65 ; 6.6B m

"##en $%&2

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Specification for 3 mm Bituminous "acadam

/. Properties of 0oarse /ggregate

i. 0os Angeles Abrasion Ealue, per cent max. =6

ii. Aggregate Impact value, per cent, max. 6iii. /la'iness and longation Indices "Total# 6iv. -tripping Ealue per cent, max. 9v. Water Absorption per cent, max. 4vi. 7etained tensile strength, minimum, per cent ?6

B. Grading of /ggregates-ieve -ize, mm )ercent by Weight )assing the -ieve

45.9 66B B6; 66.4 95;??

=.>9 5; 54. 5 =; B

66 micron 4; 6>9 micron 6;?

0. Auantities of binder i. )rime +oat for 6 - .m 5'gii. Tac' +oat for 6 s .m. Area "+ationic bitumen emulsion#:

4.9 'g for primed W % surface

ii. Binder 0ontent for aggregates! &.& to &. per cent by #eight of mi(. %. 0onstruction Operation

Apply prime coat of cationic emulsion O 5 'g8s m Apply tac' coat of cationic emulsion O 4.9 'g8s mTemperature of bitumen at the time of mixing shall be 96; 5 P+ and that of

aggregate shall be 99; 5 P+.Temperature of mix at the time of laying shall be minimum 49P+.+ompaction of mix shall be completed before temperature of mix falls belo! 66P+.

Appendix-4

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Specifications for 3 mm hic$ %ense Bituminous "acadam %esign0riteria

i# @o of blo!s on each face >9 ii# %arshall -tability "%in#, 'g B66

iii# %arshall flo! , mm 4 ; =iv# C voids in the mix ; 566666666 v# C voids in mineral aggregate filled by the

binder 59 ; >9

B. Grading of /ggregate-ieve -ize mm )ercent )assing

>.9 6645.9 B6; 66

B > ;B9.4 95;?6

=.>9 ?;9=4. 5 4?;=466N >;4

>9N 4;?

0. Physical properties of aggregatesi. 0os Angeles Abrasion Ealue, per cent max. 9ii. Aggregate Impact value, per cent, max 4>iii. /la'iness and longation Indices "Total# 6iv. -tripping Ealue percent, max. 9

v. Water Absorption percent, max. 4vi. -oundness lossa# !ith -odium -ulphate, 9 cycles per cent 4

b# !ith %ag. -ulphate, 9 cycles per cent ?vii. 7etained tensile strength min. percent ?6

%. Auantity of binder for!inder for mix design, per cent @ot less than =.9 per cent

'. Permissible -ariations from ob "i( ormula)assing B mm sieve D large, per cent ?)assing .4 mm sieve D B.9 mm sieve, per cent >

)assing =.>9mm sieve, per cent 5)assing 4. 5 mm sieve D 566 micron sieve, per cent 9)assing 66 micron sieve and retained on 96 micron sieve, percent

=

)assing >9 micron sieve, per cent 4itumen, per cent 6.

%ixing Temperature 6 +

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. emperatures for 0onstruction Operations

i. Temperature of bitumen at the time of mixing 96 ; 5 P+ii. Temperature of Aggregate at the time of mixing 99 ; 5 P+iii. Temperature of mix at the time of laying 46 ; 56P+iv. 7olling operations shall be completed before the temperature of the mix falls

belo! 66P+

C*ote! %ifference in temperature bet#een aggregate and bitumen should notbe more than 1 P0

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/ppendi(@Specifications for 3 mm hic$ Bituminous 0oncrete %esign 0riteria

i# @o of blo!s on each face >9ii# %arshall -tability "%in#, 'g B66

iii# %arshall flo! , mm 4 2 =iv# C voids in the mix 2 566666666 v# C voids in mineral aggregate filled by the

binder 59 2 >9

vi# 0oss of stability on immersion in !ater at 56 P+, minimum retained strength, per cent

>9

B. Grading of /ggregateSieve Si;e mm Percent Passing

B 66.4 >B; 66

B.9 >6;??=.>9 9 ;>4. 5 =4;9?

. ? =;=?566N 45; ?

66N ?;4?96N 4;46

>9N =; 6

0. Physical properties of aggregatesi. 0os Angeles Abrasion Ealue, per cent max. 6ii. Aggregate Impact value, per cent, max 4=iii. /la'iness and longation Indices "Total# 6iv. -tripping Ealue percent, max. 9v. Water Absorption percent, max. 4vi. -oundness loss

a# !ith -odium -ulphate, 9 cycles per cent "max# 4 b# !ith %ag. -ulphate, 9 cycles per cent "max# ?

vii. 7etained tensile strength min. percent ?6viii. +leanliness, Grain size analysis, per cent passing >9 micron "max# 9

%. Auantities of binder!

inder for mix design, per cent @ot less than 9 per cent

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'. Permissible -ariations from ob "i( ormula)assing B mm sieve D large, per cent ?

)assing .4 mm sieve D B.9 mm sieve, per cent >)assing =.>9mm sieve, per cent 5)assing 4. 5 mm sieve D 566 micron sieve, per cent 9)assing 66 micron sieve and retained on 96 micron sieve, per cent =)assing >9 micron sieve, per cent 4

itumen, per cent 6.%ixing Temperature 6 +

. emperatures for 0onstruction Operations

i. Temperature of bitumen at the time of mixing 96 ; 5 P+ii. Temperature of Aggregate at the time of mixing 99 ; 5 P+iii. Temperature of mix at the time of laying 46 ; 56P+iv. 7olling operations shall be completed before the temperature of the mix falls

belo! 66P+

C*ote! %ifference in temperature bet#een aggregate and bitumen should notbe more than 1 P0

bila spur report final

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