A STUDY ON FACTORS AFFECTING STRENGTH OF BITUMINOUS … · accidents, loss of life and revenue. Normally a good strength is obtained at the design temperature and design compaction

DOI:10.21884/IJMTER.2016.3136.NLM7W 149

A STUDY ON FACTORS AFFECTING STRENGTH OF

BITUMINOUS PAVEMENT

Mr. Jalindar Galande1 and

Mr.Vikram Yendhe

2

1Civil, P.Dr.V.V.P Institute of Technology & Engineerin (Polytechnic), Loni,Tal-Rahata,

Dist-Ahmednagar, Maharashtra, 413736, India. 2Mechanical, P.Dr.V.V.P Institute of Technology & Engineering (Polytechnic), Loni,Tal-Rahata,

Dist-Ahmednagar, Maharashtra, 413736, India.

Abstract- Strength of chip carpet or wearing coat depends on the mix temperature, viscosity of

bitumen and the cyclic load to which the wearing coat is subjected. Failure of pavements results in

accidents, loss of life and revenue. Normally a good strength is obtained at the design temperature

and design compaction load. The project work is to study the different types of pavements, load

coming on pavement, design considerations. Factors affecting the strength of wearing coat which

will result in long life of the wearing coat will be studied. Relation between temperature, viscosity,

degree of compaction on strength and stability of wearing coat will be studied through laboratory

test. And aggregate bitumen mix, laying temperature are specified for the mentioned case. The result

will be used to plan the asphalting process which will result in Long Life of the pavement.

Keywords- Bituminous Pavement, Bitumen, Aggregate, VMA Test, VFB Test, Stability Test.

I. INTRODUCTION

Transportation contributes to the economic, industrial, social and cultural development of any

country. The transportation by road is the only mode which could give maximum service to one and

all. The pavement is improved by adding extra crust. Single lane pavements were widened and

strengthened to cope with the increasing traffic and to make traffic movement quick and safe. Thus

apart from quantitative increasing in kilometers, there has been marked qualitative improvement in

the highways all over the country. Billions of money is spent on maintenance of constructed road due

to various reasons. Failure of wearing coat results due to improper conditions in connection with

quality, quantity and standard condition not followed. Strength and durability of wearing coat is

derived by the cohesive bonding of bitumen, aggregate and is dependent on the mix quality and

mixing conditions like temperature, viscosity, transportation time, geo-climatic condition. Failure to

obtain given grade of strength will result in development of ruts and corrugations leading to failure

of the wearing coat. To study the damages to the wearing coat due to various factors through

literature survey. To test the material for there suitability to used in pavement construction. To study

the effect of temperature & mix proportion on stability and flexibility of mix by Marshall stability

test. To suggest a suitable pavement mix for college campus approach road. Pavements form the

basic supporting structure in highway transportation. Each layer of pavement has a multitude of

functions to perform which has to be duly considered during the design process. Different types of

pavements can be adopted depending upon the traffic requirements. Improper design of pavements

leads to early failure of pavements affecting the riding quality also.

Fig.1 Potholes caused by poor drainage on pavement.

International Journal of Modern Trends in Engineering and Research (IJMTER) Volume 03, Issue 11, [November – 2016] ISSN (Online):2349–9745; ISSN (Print):2393-8161

@IJMTER-2016, All rights Reserved 150

1.1 Road cross section

A flexible pavement are constructed of several layers of natural granular material covered

with one or more waterproof bituminous surface layers, and as the name imply, is considered to be

flexible.

Fig.2 Typical cross section of a flexible pavement.

1.2 Types of Flexible Pavements

The following types of construction have been used in flexible pavement:

Conventional layered flexible pavement,

Full - depth asphalt pavement, and

Contained rock asphalt mat (CRAM).

Conventional flexible pavements are layered systems with high quality expensive materials

are placed in the top where stresses are high, and low quality cheap materials are placed in lower

layers. Full - depth asphalt pavements are constructed by placing bituminous layers directly on the

soil sub grade. This is more suitable when there is high traffic and local materials are not available.

Contained rock asphalt mats are constructed by placing dense/open graded aggregate layers in

between two asphalt layers. Modified dense graded asphalt concrete is placed above the sub-grade

will significantly reduce the vertical compressive strain on soil sub-grade and protect from surface

water.

1.3 Typical layers of a flexible pavement:

Typical layers of a conventional flexible pavement includes seal coat, surface course, tack

coat, binder course, prime coat, base course, sub-base course, compacted sub-grade, and natural sub-

grade Seal Coat: Seal coat is a thin surface treatment used to water-proof the surface and to provide

skid resistance.

Tack Coat: Tack coat is a very light application of asphalt, usually asphalt emulsion diluted with

water. It provides proper bonding between two layer of binder course and must be thin, uniformly

cover the entire surface, and set very fast.

Prime Coat: Prime coat is an application of low viscous cutback bitumen to an absorbent surface

like granular bases on which binder layer is placed. It provides bonding between two layers. Unlike

tack coat, prime coat penetrates into the layer below, plugs the voids, and forms a water tight surface.

Surface course: Surface course is the layer directly in contact with traffic loads and generally

contains superior quality materials. They are usually constructed with dense graded asphalt concrete

(AC). The functions and requirements of this layer are:

Binder course: This layer provides the bulk of the asphalt concrete structure. It's chief purpose is to

distribute load to the base course The binder course generally consists of aggregates having less

asphalt and doesn't require quality as high as the surface course, so replacing a part of the surface

course by the binder course results in more economical design.

Base course: The base course is the layer of material immediately beneath the surface of binder

course and it provides additional load distribution and contributes to the sub-surface drainage It may

be composed of crushed stone, crushed slag, and other untreated or stabilized materials.

Sub-Base course: The sub-base course is the layer of material beneath the base course and the

primary functions are to provide structural support, improve drainage, and reduce the intrusion of



fines from the sub-grade in the pavement structure If the base course is open graded, then the sub-

base course with more fines can serve as a filler between sub-grade and the base course A sub-base

course is not always needed or used. For example, a pavement constructed over a high quality, stiff

sub-grade may not need the additional features offered by a sub-base course. In such situations, sub-

base course may not be provided.

Sub-grade: The top soil or sub-grade is a layer of natural soil prepared to receive the stresses from

the layers above. It is essential that at no time soil sub-grade is overstressed. It should be compacted

to the desirable density, near the optimum moisture content.

Sub grade soil: Soil is an accumulation or deposit of earth material, derived naturally from the

disintegration of rocks or decay of vegetation that can be excavated readily with power equipment in

the field or disintegrated by gentle mechanical means in the laboratory. The supporting soil beneath

pavement and its special under courses is called sub grade. Undisturbed soil beneath the pavement is

called natural sub grade. Compacted sub grade is the soil compacted by controlled movement of

heavy compactors.

III. MATERIALS AND METHODS

3.1 Materials

Coarse aggregates: The coarse aggregates shall consist of angular fragments and be clean, hard,

tough, durable and of uniform quality throughout. They shall be crushed rock, gravel, river shingle or

slag and should be free of elongated or flaky pieces, soft and disintegrated material, vegetable or

other deleterious matter. The aggregates shall satisfy the properties

Fine aggregates: The fine aggregates for premixed seal coat shall be crushed stone dust, sand, or grit

and shall consist of clean, hard, durable, uncoated, coarse dry particles, and shall be free from dust,

soft or flaky particles, organic matter or other deleterious substances. The sand equivalent value of

fine aggregate shall be 60 (min) as tested by test method given in IS:2720(Part 37).

Binder: The binder for premix carpet and sealcoat shall be one of the following types as directed by

the Engineer:

(i)A paving bitumen of suitable penetration grade conforming toIS:73.

(ii)A modified bitumen conforming to IRC:SP:53. The binder for tack coat shall be rapid setting

cationic bitumen emulsion conforming to IS:8887. In snow bound areas, where use of emulsion or

paving bitumen is not feasible, cut back bitumen conforming to IS :2 17or IS:454 may be used with

the approval of Engineer-in-Charge.

3.2 Quantities of Materials Required

Aggregates: The quantity of aggregates required for premix carpet and seal coat is given in Tables 3

and 4 respectively

Table.1 Quantity of Aggregates for Premix Carpet.

Type of

seal coat Aggregate size

Quantity per 10m2

area of road surface

A Coarse aggregates- 6.7 mm size (passing IS 11.2 mm square mesh

sieve, retained on IS 2.8mm square mesh sieve) 0.09m

3

B Fine aggregate – Medium coarse sand (fineness modulus of more than

2.5) or fine grit ( passing IS sieve No. 2.36 mm and retained on IS

Sieve no. 180 microns) 0.06 m

3

Binder: The quantity of binder required for tack coat, premix carpet, and seal coat is given in Tables

as below.

Table. 2 Quantity of Aggregates for Seal Coat.

Aggregate size Quantity per 10m

2 of

road surface

Coarse aggregate-Nominal size 13.2mm(passing IS:11.2mm square mesh sieve 0.18m3



and retained on IS 11.2mm square mesh sieve)

Coarse aggregate-Nominal size 11.2mm(passing IS:13.2mm square mesh sieve

and retained on IS 5.6mm square mesh sieve) 0.09 m

3

Total quantity of aggregate 0.27 m3

Table.3 Quantity of Binders for Tack Coat.

Item Quantity per 10m2 area of road surface

On a granular surface(primed) 2.5 to 3.5kg

On an existing black top surface* 2.0 to 3.0kg

*In case the existing black top surface is extremely rich in binder, or fatty, the tack coat may be eliminated in

hot climate region at the discretion of the engineering in charge, if a good bond between the existing surface

and the superimposed lay6er can be ensured.

Table.4 Quantity of Binder for Premix Carpet

Item Quantity per 10m2 area of road surface

For 13.2 mm size coarse aggregate 9.5 kg @ 52 kg per m3

For 11.2 mm size coarse aggregate 5.1 kg @ 56 kg per m3

Total 14.6 kg

Table.5 Quantity of Binder for Seal Coat

Type of seal coat Quantity per 10m2 area of road surface

Type A(liquid seal coat) 9.8kg

Type B(premixed seal coat) 6.8kg

3.3 Preparation of surface:

The underlying surface on which the bituminous surface is to be laid must be free from dust,

caked mud or any loose and extraneous matter and shall be prepared and shaped to the specified

profile. Where the existing surface is potholed or rutted, these irregularities must be corrected with

premixed chippings or coated macadam, depending upon the depth of the depressions or pothole, laid

after applying a tack coat of binder and well rammed, thereafter. The surface should be swept clean

by removing caked earth and other foreign matter with wire brushes sweeping with brooms

(mechanical broom) and finally dusting with air jet, washing or other means approved by the

Engineer-in-Charge. On granular surface prime coat shall be applied as per IRC: 15.

As soon as sufficient length (say20-25 m) of the premix has been laid, rolling should

commence with 8-10 tone smooth wheeled tandem type rollers or other approved roller. Rolling

should commence at the edges and progress towards the center longitudinally except in the case of

super-elevated sections, where this should commence at the inner edge and proceed towards the

outer edge of the curve. When the roller has passed once over the whole area, any high spot or

depression which becomes apparent should be corrected by removing or adding the same premixed

material. Rolling shall then be continued until the entire surface has been rolled and the roller marks

eliminated. In each pass of the roller, the preceding track shall be covered uniformly by at least

1/3width. Excessive rolling shall be avoided. Moisten the roller wheels with minimum possible

amount of water to prevent the premix from adhering to the wheels and being picked up. In no case

shall fuel/lubricating oils will be used for this purpose. Excess use of water for this purpose shall be

avoided. The rolling operation should be completed before temperature of mix reaches the values

given in Table 6. Table.6 Manufacturing and Rolling Temperature with Different Grades of Bitumen/Modified Bitumen

Bitumen

penetration

Range of temperature oc

Bitumen

mixing

Aggregate

mixing

Mixed material at Rolling

Disacharge Laying site

30-40 160-170 160-175 170

maximum

130

minimum

100

Minimum



60-70 150-165 150-170 165

maximum

125

minimum

90

Minimum

80-100 140-160 140-165 155

maximum

115

minimum

80

Minimum

Modified bitumen * 165-185 155-175 160

maximum

130

minimum

115

Minimum

* The above Table gives broad range of temperatures, exact temperatures depend upon the type and amount

of modifier used and shall be adopted as per advice of supplier or test data modified bitumen at diff.

temperature.

IV. MATERIAL TESTING

4.1 Tests on bitumen

4.1.1 Penetration Test:

Fig.3 Penetrometer.

The consistency of bituminous materials varies depending upon several factors such as

constituent, temperature, etc. At temperature ranges between 25 and 50°C most of the paving

bitumen grades remain in semi-solid or in plastic states and their viscosity is so high that they do not

flow as liquid. But the viscosity of most of the tars and cutbacks are sufficiently low at this

temperature range to permit these bituminous materials to be in a liquid state, enabling some of the

grades to be mixed with aggregates even without heating.

Test sample: The material is softened the material to a pouring consistency at a temperature not

more than 60°C for tar&90°C for bitumen. Stir it thoroughly until it is homogenous & free from air

bubbles & water. The melted material is poured into a container to a depth not less than 10mm In

order to get expected penetration& to protect the sample against dust it is allowed to cool in an

atmosphere at a temperature between 15-30°C ± 1°C . The sample is allowed to remain for about 1 to

1.5 hrs.

Procedure: The transfer dish is filled with water in the bath such as to cover the container

completely, place the sample in the dish and put it on the base of Penetrometer. The needle is cleaned

with benzene and dries it. Loaded with weight, the total moving load required is 100 ± 0.25 gm.,

including the wt. of the needle, carrier & the superimposed load. Adjust the needle to made contact

with the surface of the material & made the pointer of the dial to zero. Release the needle for 5 sec.

& adjust the machine to read penetration. Perform and take three readings with spacing not less than

10mm from the face of the container. In case of material with penetration more than 225, penetration

was determined on two identical specimens using a separate needle on completion of each

determination to avoid disturbance of the specimen.



4.1.2 Determination of softening point

Fig.4 Ring and ball apparatus.

Apparatus: Steel balls- two nos. each of 9.5mm dia. And weighing 3.5 ± 0.05 gm. Brass rings- two

nos. each having depth of 6.4 mm. The inside dia. At bottom and top is 15.9mm and 17.5mm

respectively. Ball guides to guide the movement of steel balls centrally. Support – that can ring in

position and also allows for suspension of a thermometer .the distance between the bottom of the

rings and the top surface of the bottom plate of the support is 25mm. Thermometer that can read up

to 100 °C with an accuracy of 0.02°C Bath: A heat resistant glass beaker not less than 85mm. in

diameter and 120mm in depth.

Procedure: Assemble the apparatus with the rings, thermometer and ball guides in position. Fill the

bath with distilled water to a height of 50 mm above the upper surface of the rings. The starting

temperature may be kept should be 5°C. Apply heat to the bath& stir the liquid so that the

temperature raised at a uniform rate of 5 ± 0.5°C per minute. As the temperature increases, the

bituminous material softens & the ball sinks through the rings, carrying a portion of the material with

it. Note down the temperature when any of the steel ball with bituminous coating touch the bottom

plate. Record the temperature when second ball also touches the bottom plate. The average of the

two readings taken to nearest 0.5°C is reported as the softening point.

4.1.3 Determination of ductility

Fig.5 Ductility mould.

Procedure to determine the Ductility of Bitumen: Completely melt the bituminous material to be

tested by heating it to a temperature of 75°C to 100°C above the approximate softening point until it

becomes thoroughly fluid. Assemble the mould on a brass plate and in order to prevent the material

under test from sticking, thoroughly coat the surface of the plate and the interior surfaces of the sides

of the mould with a mixture of equal parts of glycerin and dextrin. While filling, pour the material in

a thin stream back and forth from end to end of the mould until it is more than level full. Leave it to



cool at room temperature for 30 to 40 minutes and then place it in a water bath maintained at the

specified temperature for 30 minutes, after which cut off the excess bitumen by means of a hot,

straight-edged putty knife or spatula, so that the mould is just level full. Place the brass plate and

mould with briquette specimen in the water bath and keep it at the specified temperature for about 85

to 95 minutes. Remove the briquette from the plate, detach the side pieces and the briquette

immediately. Attach the rings at each end of the two clips to the pins or hooks in the testing machine

and pull the two clips apart horizontally at a uniform speed, as specified, until the briquette ruptures.

Measure the distance in cm through which the clips have been pulled to produce rupture. While the

test is being done, make sure that the water in the tank of the testing machine covers the specimen

both above and below by at least 25mm and the temperature is maintained continuously within ±

0.5°C of the specified temperature.

4.1.4 Flash Point And Fire Point.

This test is done to determine the flash point and the fire point of asphaltic bitumen and

fluxed native asphalt, cutback bitumen and blown type bitumen as per IS: 1209 – 1978. The principle

behind this test is given below:

Fig.6 Flash and Fire Point.

Flash Point: The flash point of a material is the lowest temperature at which the application of test

flame causes the vapors from the material to momentarily catch fire in the form of a flash under

specified conditions of the test.

Fire Point: The fire point is the lowest temperature at which the application of test flame causes the

material to ignite and burn at least for 5 seconds under specified conditions of the test. The apparatus

required for this test is Pesky-Martens apparatus.

Flash Point Procedure: Soften the bitumen between 75°C and 100°C. Stir it thoroughly to remove

air bubbles and water. Fill the cup with the material to be tested up to the filling mark. Place it on the

bath. Fix the clip. Insert the thermometer of high or low range as per requirement and also the stirrer,

to stir it. Light the test flame, adjust it. Supply heat at such a rate that the temperature increase,

recorded the thermometer is neither less than 5°C nor more than 6°C per minute. Open flash point is

taken as that temperature when a flash first appears at any point on the surface of the material in the

cup. Take care that the bluish halo that sometimes surrounds the test flame is not confused with the

true flash. Discontinue the stirring during the application of the test flame. Flash point should be

taken as the temperature read on the thermometer at the time the flash occurs.

Fire Point Procedure: After flash point, heating should be continued at such a rate that the increase

in temperature recorded by the thermometer is neither less than 5°C nor more than 6°C per minutiae)

The test flame should be lighted and adjusted so that it is of the size of a bead 4mm in dia.

4.1 Tests on aggregates

4.2.1 Sieve analysis: Sieve analysis helps to determine the particle size distribution of the coarse and

fine aggregates. This is done by sieving the aggregates as per IS: 2386 (Part I) – 1963. In this we use

different sieves as standardized by the IS code and then pass aggregates through them and thus

collect different sized particles left over different sieves.



Procedure to determine particle size distribution of Aggregates: The test sample is dried to a

constant weight at a temperature of 110°C + 5°C and weighed. The sample is sieved by using a set of

IS Sieves. On completion of sieving, the material on each sieve is weighed. Cumulative weight

passing through each sieve is calculated as a percentage of the total sample weight. Fineness

modulus is obtained by adding cumulative percentage of aggregates retained on each sieve and

dividing the sum by 100.

4.2.2 Abrasion test

Fig.7 Los Angeles abrasion test apparatus.

It consists of hollow steel cylinder closed at both ends with an internal diameter 700mm ,

length of 500mm, a detachable cover is provided which when closed is dust tight .A shaft projecting

88mm into the cylinder for whole of its length mounted firmly inside the cylinder . A shelf is

provided at a distance of 1250mtT,from the opening in the direction of rotation. Abrasive charge

:These are the cast iron steel balls of about 48mm diameter weighing about 390 – 450 gm. About 6 to

12 balls are used . The 1.70mm I.S. sieve. Laboratory oven, trays etc.

Procedure: Open the cover & pour the sample with steel balls & close the cover tightly. Rotate the

machine uniformly at the rate of 30 to 3 rpm Allow 500 rotations for A,B,C,D and 1000 for E, F & G

grading. Stop the machine & take out sample in a tray, and separated out the steel balls & then sieved

the sample through 1.7 mm I.S. sieve. Wash out the coarse material & dry it an oven, weigh

accurately up to 1 gm& calculate tie loss of material.

4.2.3 Impact test

Procedure: The test sample: It consists of aggregates sized 20mm to 12.5mm. The aggregate should

be dried by heating at 100- 110°C for a period of 4 hours& cooled. Sieve the material through

12.5mm &10mm IS sieves. The aggregates passing through 12.5mm sieve & retained on 10 mm IS

sieve comprises the test material. Pour the aggregates to fill about just 1/3rd

depth of measuring

cylinder. Compact the material by giving 25 gentle blows with rounded end of tamping rod. Add two

more layers in similar manner, so that cylinder is full. Struck off the surplus material. Determine the

net weight of aggregates to nearest gm.(W1) Bring the impact machine to rest without wedging or

packing upon the level plate, block or floor, so that it is rigid and columns are vertical, Fix the cup

firmly in position on the base of the machine & place whole of the test sample in it & compact by

giving 25 gentle strokes with tamping rod. Raise the hammer until its lower face is 380mm above the

surface of aggregate sample in cup & allow it to fall freely in the aggregate sample. Give 15 blows at

an interval of not less than one second between successive falls, Note down the observations in the

perform & compute the A.I.V. The mean of two observations, rounded to the nearest whole number

are reported as A.I.V.



Fig..8 Aggregate impact value apparatus.

4.2.4 Marshall stability test

Fig.9 Marshall Stability apparatus.

Procedure: Specimens were heated to 60°C±1°C (37.8°C±1°C, for specimens in which tar was used

in place of bitumen.) either in a water bath for 30-40 min. or in oven for a minimum of 2 hrs.)

Remove the specimen from the water bath or oven and place in the lower segment of breaking head.

Then place the upper segment of the breaking head on the specimen on the completed assembly in

position on the testing machine. Place the flow meter over one of the post and adjust it to read zero.

Apply the load at a rate of 50mm/min until the maximum load reading was obtained. Record the

maximum load reading in Newton‟s (N). at the same instance obtained the flow as recorded on the

flow meter in units of mm.



V. PRESENTATION OF RESULTS

5.1 Tests On Bitumen

Penetration test for bitumen:

Actual test temperature = 15 -200C. Table.7 Penetration test for bitumen.

Description Test 1 Test 2 Test 3

Penetration value 10.6 12.8 11.5

Mean penetration value = 11.63.

Determination of softening point:

Table.8 Softening point Result.

Description Ball no.1 (°C) Ball no.2(°C) Mean temp. °C

Temp , when the ball

touches bottom , °C 58 60 59

Ductility Test:

Table.9 Ductility value test.

Reading Observations

Initial reading (x) 0 0 0

Final reading (y) 102 98 100

Ductility value(y-x) 102 98 100

Flash Point And Fire Point:

Table.10 flash &fire test.

Description Sample

Flash point 190°C

Fire point 235°C

Table.11 Grading of sieve

5.2 Aggregate Crushing Value

Total weight of the dry sample =W1 = 3030

Total weight of aggregate passing through 2.36mm IS sieve = W2=824.

Calculation: Crushing value of the given sample of aggregate = (W2/W1)*10= 27.19%.

Result: Aggregate crushing value of the given sample = 27.19%.

5.3 Abrasion test

Observations:

Grading selected : C. ,Original weight of sample , W1 = 4750g.

Weight of aggregate retaine.d on 1.7mm I.S. sieve ,W2 = 3644.

Maximum size present in substantial potential(mm) Minimum weight of sample dispatch for testing(kg)

63 100

50 100

40 50

25 50

20 25

16 25

12.5 12

10 6

6.3 3



Loss of weight(W1- W2) = 1106.

Los Angeles abrasion value = 23.28%.

5.4 Impact test Table.12 Impact test Results.

Description Sample 1

Total weight of dry sample taken = W1 gm 606

Weight of portion passing 2.36mm sieve= W2 gm 58

A.L.V.= W2/W1 x 100 % 9.57

Result :

Aggregate impact value=9.57 (Exceptionally strong).

5.5 Shape test

Observations Table :

Thickness Gauage Table.13 Thickness Gauge.

Size of

sieve

(mm)

Retained

on

Mean

diameter

Size of

thickness

gauge

Size of

length gauge

Weight of

aggregate passing

through thickness

gauge

Weight of

aggregate retained

on length gauge

63 50 56.5 03.90 101.70 - -

50 40 45.0 27.00 81.00 - -

40 31.5 35.75 19.50 64.34 - -

31.5 25 28.25 16.95 50.85 22 86

25 20 22.50 13.50 40.50 34 602

20 16 18.00 10.80 32.40 116 1046

16 12.5 14.25 08.55 25.65 60 496

12.5 10 11.25 06.75 20.25 4 20

10 6.3 08.15 04.89 14.67 - -

6.3 1.0 03.65 02.59 06.57 - -

W2 = 236 2250

Results :

1) The flakiness index of the aggregate sample was = 9.49

2) The elongation index of the aggregate sample was = 23.25

5.6 Marshall stability test: Table.14 Marshall stability test

Description SAMPLE

01

SAMPLE

02

SAMPLE

03

Mass of aggregates in mixing pan 1200 1200 1200

Mass of bitumen added 60 66 72

Bitumen content % 5 5.5 6

Mixing temp. for aggregate & bitumen 160 165 170

Table.15 Compacting temperature.

Compacting temperature 01 02 03

Mass of specimen in air (Ha) 1252 1235 1244

Mass of submerged in water (Hw) 720 722 735

Vol. of specimen (V) in cubic cm. 547 534 525

Ht. of specimen (cm) 6.76 6.8 6.57



Table.16 Computation of Result.

Description Sample 1 Sample 2 Sample 3

Density of compacted mix,„d‟. 2.29

2.31 2.37

Specific gravity of mix (g /cu.cm) 2.44

2.44

2.44 2.44

Volume of bitumen 15.30

15.30

36.81 50.41

Volume of aggregates 78.5

78.50

57.97 46.70

Voids in mineral aggregate V.M.A.=Vm = (100 - Va)

21.5

21.50

42.03 53.30

Voids filled with bitumen = V. F.B. 71.19

71.19

87.59 94.58

Measured stability , Kg 1077 1012 980

Flow value (mm). 3.9 4.5 4.6

Fig.11 Bitumen Content VS VMA.

Fig.12 Bitumen Content VS Flow.

Fig.13 Bitumen Content VS VFB.



Fig.14 Bitumen Content VS Stability.

Fig.15 Bitumen Content VS S Unit Weight.

Fig.16 Bitumen Content VS Flow.

VI. CONCLUSION

The standard penetration test shows A25 grade bitumen and the softening point shows that the

bitumen used needs to be of higher softening point since Loni and its adjoining area is in semi-

arid region.

Its temperature maximum up to 40-42oc.The flash and fire point for the given test material

represent good grade and bitumen as the average fire point is 235oc.The specific gravity value is

1.032 which shown higher penetration grade bitumen.

It is also a representation of qualitative estimation of mineral impurity in the bitumen. However

the value obtained is slightly higher for A25 grade bitumen which should have a specific gravity

of 0.99.The crushing strength is suitable for road construction as per the IRC recommendation.

The abrasion and impact test value suggest that the aggregate is of good quality for construction

of bituminous pavement.



The Marshall stability test shows that the mix design I Has the greater stability with the aggregate

mass of 1200gm and bitumen of 60gm which represents 5% of bitumen content.

The operating temperature represents that at 160oc higher stability is obtained also the flow value

is 3.9mm only. However all these 3 samples have stability above the minimum specified value

and the flow value lies between 2mm-4mm hence it can be concluded that the mix design is

suitable from stability and flexibility point of view.

REFERENCES

[1] Dr. Khanna. S. K. & Justo. C. E. G., Highway Engineering, Ninth Edition(2011), Nem Chand & Bros, Roorkee,

U.K, India.(Page No. 15 & 21 To 24.)

[2] Dr. Sharma. S. K., Principles, Practices and Design of Highway Engineering, Revised Edition, S. Chand & Company

Ltd. (Page No.7.)

[3] IRC 37 (Design of flexible pavement), clause 3.2, pg. no. 6

[4] IRC: SP:42:2014, Guidelines of surface drainage, Page no- 11, 12, 13.

[5] Khanna S. K. & Justo C. E. G., Highway material testing (laboratory manual), 4th

edition, Nem Chand & Bros,

roorkey India.

[6] Sharad S. Adlinge, Prof. A .K. Gupta, “IOSR Jouranal of mechanical & civil Engg.(IOSR - JMCE)”,Pavement

Deterioration & its causes.

[7] Tom. V. Methew, K. V. Krishnarao, “Factors affecting pavement design”, Chapter 20,NPTEL, Page no- 20.1, 20.2,

May 03, 2007.

[8] Tom. V. Methew, K. V. Krishnarao, “Flexible pavement design”, Chapter 27, NPTEL, Page no- 27.2, 27.3, May 03,

2007.

[9] Tom. V. Methew, K. V. Krishnarao,“Introduction to pavement design”, Chapter 19, NPTEL Page no- 19.3, 19.4,

May 03, 2007.

[10] Tom. V. Methew, K. V. Krishnarao, “IRC methods of design of flexible pavement”, Chapter 28, NPTEL, Page no-

28.3, 28.4, May 03, 2007.

[11] Tom. V. Methew, K. V. Krishnarao, “Pavement material: Aggregate” ,Chapter 22,NPTEL, Page no- 22.1, 22.2, May

03, 2007.

[12] Tom. V. Methew, K. V. Krishnarao, “Pavement material: Soil”, Chapter 21, NPTEL, Page no- 21.1, May 03, 2007.

[13] Tom. V. Methew, K. V. Krishnarao, “Traffic data collection”, Chapter 32, NPTEL, Page no- 32.5, 32.6, May 03,

2007

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