Babati Project Min Presentaion

7/30/2019 Babati Project Min Presentaion

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PROJECT TITLE: INVESTIGATOIN OF THE CAUSES

OF FAILURE Of GRAVEL ROAD

PROPROJECT TYPE: PROBLEM SOLVING

CASE STUDY: KAMAL INDUSTRIAL ESTATE ROAD

KEREGE IN BAGAMOYO DISTRICTNAME: BABATI M. SHIHUMBILA

ADM NO:1001016992

COURSE: OD 10 CIVIL


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KAMAL INDUSTRIAL ESTATE ROAD NETWOR


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INTRODUCTION

Road is constructed by composite materials

that carry the weight of people and vehicle

loads. The thickness of road, width road and

type should vary based on the planned

function of the road area is designed to

provide Superior infrastructure facilities.


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PROBLEM STATEMENT

water settlement to the gravel road which

cause defect like corrugation, pothole and ruts


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OBJECTIVES

Main objective

To investigate causes of the road failure.

Specific objectiveTo provide suitable method of solving the

problem.


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PROJECT OUTCOME

At the end of this project the causes of

Failure of road will be identified and

provide method of solve the problem.


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ADOPTED METHODOLOGY

The methodology adopted in carrying out

Literature review: Through reading different

books and information obtained about

investigation of road failure

Data collection: is a term used to describe a

process of preparing and collecting data.data analysis: is done according to the data

collected from the site


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Literature review

History of roads construction

Roads is primary means of communicationof people in the country. Road is very

important role in development economic. Ithas been described as veins and arteries forthe flow of the economy of thenational(1984,vazirani). Road

is built in social, cultural and political tofacilitate life of people though efficient oftransportation system.


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Literature review cont

Characteristic of road

(a) it is easy to invest compared to other

mode of transportation.

(b) provide great freedom to the user

(c) have many number of user.

(d) preferable mode of transportation forshort distance.

(e) provide door to door services.


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Types of road

In road construction there deferent

types of road which ca be construct

according to the se of lection of road.

There two types of unpaved roads which

constructed. these area(a) Gravel road

(b) Earth road


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Gravel road

It is a road constructed by gravel whichcontain binding material such as clay for

construction sub base course, base courseand wearing course. These road areimprovement over the earthen road and can

take 60-100 tones of pneumatic and irontyred traffic.


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Component of gravel Road layers

road are:-(a)sub base course

This layer protect the imposed wheel loads and carrythe weight of base course layer.

(b)base course

The layer is should be stronger enough to carry theload.

(b)Wearing course

This layer provide a smooth surface and carry thewheel load and transfer to base course.


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Defects on gravel road

The defect which formed on gravel road such as:-

(a)Pothole

This is the set of hole which formed on the roadsurface.

(b)Corrugation

This defect formed and cause failure of road

when water settle to the camber.


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(c)RutsIs the simple operation of camber function feature.

(d)Lost of shape

The shape of camber disappear and cause watersettle or flowing Cause open to loose smoothness.

(e)Soft spot

This is the behavior the road having weak.


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Investigation of gravel road failure

The investigation of the road failure could bedefined as a discontinuity in a road due toformation of ruts,potholes,corrugation, lost ofshape and soft spot. a road is supported to be acontinuous stretch for smooth drive. If visibleruts, potholes, corrugation, lost of shape, andsoft spot may affect smooth drive. The effect

in smooth drive is generally regarded a roadfailure.


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According to these defects formed to the road

pavement during the rainfall water settle to

the road pavement. Once water has entered

to the road cause damage of pavement andcause hydraulic pressure to the road .Also

when vehicle passing over the road pavement

impact considerable sudden pressure on thewater.


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Study area description

The road investigation in this study is the

gravel road 690m existing in kamal Industrial

Estate. At the time of study the road undergo

failure due to formation of ruts, potholes,corrugation, lost of shape and soft spots

which sight on portions of the road way.


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Field procedure

For using chisel, hammer and tape measure

equipment was used to acquire the data .for

interval of 230m the sample taken along the

road up to 690m.


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TEST TO BE DONE

(a)GRADING TEST

This is the test done to classify the the soil and

determine if it is whether gravel, sand, silt or clay

(b)ATTERBERG TEST

The test is to determine the properties of thesoil and it consists of liquid test, plastic limit andplasticity index and lastly linear shrinkage test.


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TEST TO BE DONE continue

(c) COMPACTION TEST

The compaction test is to obtain therelationship between max dry density whichcan be achieve for soil depends on thedegree of compaction applied and themoisture content.

(d)CALIFORNIA BEARING RATIO TEST(BCR)

The strength of sub grade is the main factor todetermine the required thickness of pavement ofthe load.


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A Particle Size Distribution Dry Sieving

-Objective of the test

- Particle size distribution analysis is a test

necessary for classification of soils, it is

present relative proportions of different sizes

of particles. This test is done to determine the

particle distribution of soil if it is gravel, sand,

silt, or clay sizes, if it is likely to control theengineering properties of the soil.


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Main Principles

The preparation of the sample by wet sieving to remove siltand clay sized particles. And dry the remaining sampleafter sieving

Sample preparation

The sample is obtained by air drying for at least 12 hoursdepending on the type of the sample

A representative sample is obtained by quartering or rifflingto give a minimum mass of about 2.5kg


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Procedures of the Test

Weigh the air dried sample to 0.1% of its total mass(m1),placethe sample and sieve through a 20mm sieve size, weigh thematerial retained on 20mm and sieve in respective sieve sizes

Weigh the material passing a 20mm test sieve(m2) and rifflethe sample to get a convenient fraction of about 0.5kg andweigh the fraction(m3)

Spread the riffled fraction in the large tray or bucket andcover with water


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Procedures of the Test

Wash the material through a 75m sieve test to remove

silt and clay

Transfer the material the material retained on the sievetest into a tray and dry in oven at 100C to 105C for 24

hours, cool and weigh the dried sample(m4)

Sieve the dried fractions through the appropriate sieves50mm to 75m sieve test. Weigh the amount retained

on each sieve and record fines passing to 75m sieve test


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Calculations

Calculate the percentage retained on each sieve

=mass of sample retained mm sieve100

total mass retained correction value

Percentage passing=100%-percentage retained for each sieve

The percentage of fines is calculated after get the percentageof passing from the table


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ATTERBERG TEST

The test is to determine the properties of the

soil and it consists of liquid test, plastic limit

and plasticity index and lastly linear shrinkage

test.

cone penetrometer instruments


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PROCTOR (COMPACTION) TEST

The test is used to provide a guide for

specifications on field compaction

Objective is to determine the relationship between compacted dry

density and soil moisture content.


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Compaction Test

Main principles

-To determine dry density which can be

achieved of a soil depend on the degree of

compaction applied and the moisture content

-The moisture content which gives the highest

maximum dry density.


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Compaction Test

The Optimum Moisture content is used forcalculating the amount of water for CBR Test

Sample Preparation Prepare sample of about 3kg of material

passing the 20mm test sieve

Test procedure

Weigh the mould, place the mould on a solidbase and attach the collar


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Compaction Test

place the sample in the mould and compact eachlayer by 27 blows using a 4.5 kg rammer

The sample is compacted in 5 equal layers, after

compacting all the layers, trim the surface of themould and weigh the mould with base plateattached

Then remove the sample and follow the range of

moisture content for each point and continuecompacting until the weight of the sample andmould is decreasing


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Calculations

Moisture content= mass of water 100

mass of dry soil

Bulk Density= mass of soilvolume of soil

Volume of soil=volume of mould

Dry density= Bulk Density

(1+moisture content)


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CALIFORNIA BEARING RATIO (CBR) TEST

Introduction

Is the basic test used to measure the strength of soil forpavement construction The CBR is required for pavementdesign to the road construction. CBR is expressed aspercentage.

Significance of the test

The test is used to provide the relative bearing value of subgrade materials. The tests is done in laboratory soilcompacted and materials are performed usually to obtain

information that will be used for selection of materials tobe use.


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Calculation

Record the penetration of 2.5mm are used for calculatingthe CBR value

CBR value (%)=P100/13.2

Record the penetration of 5.0mm are used for calculating

the CBR valueCBR value (%)=P100/20

where

p=plunger force in KN

P=(m3-m2/Vm)1000

Where, m3 is the mass of soil+mould and base plate

M2 is mass of base platein(g)


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Swell calculation

S= (K-L) 100

127

S is swelling expressed as percentage

K is the dial gauge reading after four days

soaking

L is the dial gauge reading before four dayssoaking


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DATA COLECTION

Data collection this is a term used to describe

a process of preparing and collecting data


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Field observation

During the time of inspection the following datas wereobtained at the site

(i ) 68 pothole defects were found(ii) Ruts defects of39m along the road were found

(iii)324 corrugation defects were found

(iv)lost of shape 47m along to the road were observed

were observed


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Total number of pothole

Defects No. of

Defects

Length from

(25-36)cm

Width from

(15-24)cm

Length from

(36-50)cm

Width from

(24-34)cm

Depth from

(6-17)cm

Depth from

(17-20)cm

pothole 68 41 36 27 32 30 38

The results pothole are given in Tables 1 as

summarized below:


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.

pothole defects were found


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The results of traffic count are given in Tables 2as summarized below:

DAY 12/12/2

012

13/12/2

012

14/12/2

012

15/12/2

012

16/12/2

012

17/12/2

012

18/12/2

012

CARS 7 10 5 15 11 15 11

p/up

and Vans

0 2 3 1 9 5 0

Lorries

over 5

tons

11 13 2 8 3 5 1

Semi

Trailer

total

vehicle

0

18

7

32

3

13

0

24

0

23

22

47

0

12


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MONTHLY RAINFALL DATA FROM BAGAMOYO

years JAN FEB MARCH APRIL MAY JUNE JULY AUG SEPT OCTO NOV

2008 57.2 50.4 180.3 298.6 58.7 1O 5.2 15 7 50 9

2009 48.2 30.7 89.4 308.3 72 18 7.2 20 15 30 6

2010 67.3 47 102.4 289 63.5 25 10.2 11 8 14 10

2011 83 58.4 236.8 238 81 12 6.2 13 4 11 5.7

2012 74 40 98 198.2 66.8 7 6 20 7 30 2


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RESULTS OF SOIL TEST

This report presents the actual observation

made during the site Investigation, the

Laboratory test results and gives the summary

of the data to ascertain various engineeringcharacteristics of soil.


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ATTERBERG LIMITS:

The results on atterberg limits are given in Table assummarized below:

Open pit Depth(cm)

Liquid

limit%

plastic

limit%

Plasticity

Index%

OP1 30 35.0 14.0 21

OP2 30 35 17 18

OP3 28 35 20 15


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COMPACTION TEST:

The results on compaction test are presented in the

table below:

Open pit Depth(mm) MDD(kg/m3) OMC(%)

OP1 300 2032 12

OP2 300 2191 8.6

OP3 280 2025 12.6


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LINEAR SHRINKAGE:

In open pits OP1 to open pit OP3, the soil hadlinear shrinkage values of 10%,9% and 7% forsamples collected at depth of 300mm and280mm for OP

1 OP

3.

CBR/ SWELL values:

In open pits OP1 to open pit OP3, the soil had CBR

values of 12% to 13% and SWELL values of 0.06%to 0.09% for samples collected at depth of 30cmto the pavement.

4 0 DATA ANALYSIS


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4.0 DATA ANALYSIS

Data analysis comes as the result of data

collected from the site and divided in to five

main parts which are

1. Field Observation

2. Traffic load count

3. Rainfall data

4. Laboratory test


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4.1 FIELD OBSERVATION

Defects Number of defects

potholes 68

corrugation 327

Total defect 395

Length of defect along the road

Ruts 39m

Lost of shape 47m

Total Length of defect along the road is 86m


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Percentage of potholes defects

So long as 68 potholes were found during field

observation as one of the data collected then

the result of this can be analyzed into

percentage as follows;

Percentage of pothole= total pothole x 100 =

Total defect

68 x 100 = 12.2%

395


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Percentage of corrugation defects

Percentage of = total corrugation x 100

corrugation Total defect

327 x 100 =82.8%

395


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Percentage of ruts defects

Percentage of ruts= length of rut x 100 =

Total length

39x100 = 45.3%

86


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Percentage of ruts defects

Percentage of = Length of lost shape x 100

Lost of shape Total length

= 47x100 = 54.7%

86


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Graph show percentage of defects


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Therefore according to the analysis defects

data show that increases of corrugation, lost

of shape, and ruts cause road failure. This fact

immediately suggests that each layer of theroad structure should be designed with

utmost care.


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4.2 TRAFFIC LOADING

Buy using the traffic count data the design

traffic loading of this gravel road should be

estimated. It`s done by converting the axle

load in to Equivalent factor which give thestandard axle when multiplied by number of

vehicle counted for each axle configuration.

The formation of CESAL will be calculated by


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CESAL calculated

CESAL =* 365 t (1-r) -+ r

t=ESAL /day =ADT

r = growth rate

n= design period


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traffic load analysisWeight of axles in

range (tones)

Mid point Number of axle(N) Equivalent factor

EF=(L/8.16)

Standard axles

=N*EF

1-3 2 74 0.0018 0.1332

3-5 4 20 0.0319 0.638

5-7 6 43 0.2507 10.7801

7-9 8 32 0.9147 29.2704

Tatol

40.8217


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Calculation sheet Out put

-The Equivalent standard axle load per day

(ESAL/day) should be calculatedESAL/day =total number ESAL

Surveying days

ESAL/day =40.8217

7 ESAL/day = 5.831

-the cumulative E quivalent stardard axle load

(CESAL) is calculated by:

CESAL= 365 t (1-r) -

7

t=ESAL /day =ADT=5.8318

r = growth rate= 6%

n= design period=5

CESAL=365x 5.8318(10.06) =0.355x10 = 0.355x10

Determination of CESAL


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Determination of CESAL

(E80million)Design traffic load class (E80X10) Table for traffic load class (TLC)

0.2 TLC02

0.2 to 0.5 TLC05

0.5 to 1 TLC1

1 to 3 TLC3

3 to 10 TLC10

10 to 20 TLC20

20 to 50 TLC50


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Therefore this road is designed of traffic load

of 0.3355x10 put this portion of road into TLC

05 which on put in pavement thickness design

of gravel road base is 165mm

The corresponding road base thickness for the

granular base course is 193mm.thus axle

loading is higher which have causedcorrugation on gravel road.


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Environmental factor like rainfall, soil erosion,

high water table and frost action cause of

gravel road failure.


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4.4 DRAINAGE SYSTEMby using data collection the depth of open

Drainage is range from 0.3m to 0.4m and the

slope is very flat .In places runoff does not

reach the drain and ponds allowing to the

gravel road Surface.

slope

0.4m

GL


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RECOMMENDED DEPTH OF SIDE DRAINAGE

The general requirement of side drainage is

0.6m and by referring of traffic count data

heavy load classes TLC 05-H to TLC 50-H

depth required is 1m (1999 Tanzaniapavement and material design manual).


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ROAD TYPE DESING DEPTH

GENERAL REQUIREMENT

DESING DEPTH

HEAVY LOAD CLASSES

TLC 05-H TO TLC 50-H

PAVED TRUNK ROAD 0.8m 1.2m

GRAVEL ROAD 0.6m 1.0m

DESIGN DEPTH REQUIRED


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DESIGN DEPTH REQUIRED

original ground level

finished road level

layer components 1.2m 1.0m

gravel road

paved road

4.4 LABORATORY TEST ANALYSIS


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4.4 LABORATORY TEST ANALYSISA:Sieve and atterberg analysis

LOCATIN 230LENGTH 460LENGTH 690LENGTH

Sieve Size:(mm) %Passing. %Passing. %Passing.

19.0 100 100 100

12.40 88 94 100

10.00 76 86 86

6.30 71 80 71

4.80 62 76 60

3.350 56 70 54

2.000 48 53 41

1.180 42 44 300.600 32 26 24

0.425 26 18 19

0.300 17 12 15

0.150 13 9 11

0.075 6 4 7

With the aid of the BS 1377 USCS


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With the aid of the BS 1377, USCS

soil sample classified

USCS NA SC SC AVERAGE

% Gravels 29 20 29 26

% Sand 54 68 56 59

% Fines 17 12 15 15

Liquid Limit LL (%) 35 35.4 35 35

Plastic Limit PL (%) 14 16.8 20 17

Plastic Index PI

(%) 21 19 15 18

Linear shrinkage

LS (%) 10 9 7 9


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UNIFIED SOIL CLASSIFICATION SYSTEM

Major divisions group Typical names Classification for

coarse-grained soilCoarse grained

soil

Sand s with

fines(appreciabl

e amount)

S C

Clayey sand,

sand-silt

mixture

Atterberg limits

above A line with.

Fine grained

soil

Silt and sands

(liquid limit

50)

M L Inorganic silt

and very fine

sands, rock

flour, salty

clayey fine

sands

1. Determine of

sand gravel from

graine-sive curve.2. Depending on

percentage of fine

coarse-grained soil

are classified as

follows.

-Less than 5%-

GW,GP,SW,SP

-More than 12%-

GM,GC,SM,SC

-5 to 12%

borderline case

requiring dual

symbols


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GRDATION CURVE

0

10

20

30

40

50

60

70

80

90

100

0.10 1.00 10.00 100.00

Percentagepassing(%)

Sieve size (mm)

Gradation Curve

230LENGTH 460LENGTH

690LENGTH


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AASHTO the soil sample classified

By using the parcentage passing No.2mm,

No.425micr and No. 75micr sieve test and liquid limit

of 35% and plastic index of 18% the soil classified as

group A-7-5 which is clayey soil. General rating the

soil is poor for construction of sub grade it is cause

failure if it is use for construction of gravel road.


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B: CALIFORNIA BEARING RATIO (CBR) TEST ANALYSIS

For test performed for analyzing the data of

California bearing ratio (CBR) show that the

material sample were predominantly silt,

grave and sand with little mechanical interlockand comparatively low strength of California

bearing ratio (CBR) less than 25%, despite

having maximum dry densities and optimummoisture contents of 15-18%.


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CALIFORNIA BEARING RATIO(CBR)ANALYSIS

Test Hole

No.

MDD(Kg/m) OMC% 95%MDD CBR AT

95%MDD

SWELL%

1 1880 15.2 1786 14 0.11

2 1829 16.2 1738 13 0.12

3 1700 18 1615 9 0.14


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DRY DENSITY AND CBR STRENGTH

1. The dry densities of the samples taken are

comparatively high, ranging from 1700 to 1829

(Kg/m). Optimum moisture contents (OMC) as one

would expect are correspondingly low.

2. Laboratory CBR values (4 day soaked) were also low

in these areas (ranging from 9 to 14%)

3. The minimum CBR Strength recommended for a base

course is 80%

5 0 CONCLUSION AND RECOMMENDATION


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5.0 CONCLUSION AND RECOMMENDATION

5.1 At Kamal Industrial Estate road the base course

layer spreading and sustaining layer of the pavement

has inadequate less and the California bearing ratio

(CBR) strength is low.

5.2 This situation is aggravated by insufficient gradients

of camber this cause poor drainage design, this allow

water to pond with consequent wetting of road

material.5.3 Therefore this obviously a mojar undertaking and

for the moment I would recommend that the whole

gravel road be rehabilitated for construction

maintenance.


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CONCLUSION AND RECOMMENDATION

5.4 I would proposal to excavate the side drain minimumdepth 0.6m to 1m from the ground level to avoid water make

variation table near to the sub base, base and wearing course

.However having said that to rehabilitate of gravel road will

not improve the drainage characteristic as it gives littleopportunity to increase surface gradients.

5.5 The testing carried out under study indicate that the gravel

sub base or base course would provide suitable and cheaper

alternative to replacing the existing base with 150mm leanmix with cement. the minimum MDD of 2200kg/m at OMC of

8.9% shall be applied in all rehabilitation.

REFERENCES


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REFERENCES

Justo.C.G., K. K. (2011). High way Engineering.

S.P, V. c. (1984). High way and soil Engineering.

Standard publisher Delhi.

Whitlo. (2001). basic soil mechanics (4th Edition

ed.). Vazirani: person education ltd publisher.

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