Internship report 2015

MAKERERE UNIVERSITY
COLLEGE OF ENGINEERING, DESIGN ART &
TECHNOLOGY
DEPARTMENT OF CIVIL ENGINEERING
SCHOOL OF ENGINEERING
SECOND YEAR INDUSTRIAL TRAINING REPORT
(8TH
JUNE TO 8TH
AUGUST 2015)
NAME: KAGANZI KENBERT
REG NUMBER: 13/U/298
DEPT SUPERVISOR: FIELD SUPERVISOR:
NAME: DR. ALBERT RUGUMAYO NAME: ENG. ROBERT K.
KAKIIZA
SIGNATURE:………………… SIGNATURE:…………………

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page i
DECLARATION
I KAGANZI KENBERT declare that this report is personally prepared and compiled by me, and
that the contents contained within this report have not been duplicated or published anywhere or
submitted to any university for any degree program by a student or any other person. I have
personally compiled it based on the experience and training I had with MBW Consults
Company, Nansana-Busunju road rehabilitation project.
NAME: KAGANZI KENBERT
REG NO: 13/U/298
STUDENT NO: 213000715
SIGN ……………………………………….
DATE ………………………………………

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page ii
DEDICATION
I dedicate this report to my parents Mr. Twinomujuni Robert and Mrs. Twinomujuni Molly and
to all my friends and family

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page iii
ACKNOWLEDGEMENTS
First and foremost, I would like to offer my appreciation to UNRA, for providing me with an
opportunity to carry out my industrial training with them.
I would like to thank the management and staff of and MBW consulting limited for the
opportunity they offered me to do undertake training with them, on top of which they tolerated
my mistakes and too many questions.
I would like to thank the resident engineers at the administration project offices for the extremely
hospitable atmosphere and assistance they availed to provide me with a very comfortable and
worthy training experience.
I would like to thank the road Inspector Mr. Godfrey Balyogera for the positive attitude,
unquestionable assistance and guidance he showed towards me, easing my training experience.
I would like to thank the materials engineer Eng. Okot Wilson and Mr. Balenzi Enock as well as
the entire laboratory staff for the guidance and readiness to approach any of my concerns during
my time in the materials laboratory.
I would finally like to thank all the MBW and Spencon staff who offered any assistance in any
way during my internship period.
I would like to thank my internship supervisor Dr. Albert Rugumayo for the assistance,
encouragement and advice he accorded me to ensure the success of my training period and this
report.
I would like to thank my parents for their unconditional willingness to meet all of my needs and
requirements as per the industrial training period, in terms of funding, advice and personal
guidance.
Finally, I would like to thank the Almighty God for the knowledge, wisdom, good health, safety
and ability he granted because without these, the success of this industrial training would not
have been possible.

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page iv
ABSTRACT
A successful industrial training is necessary for the award of a degree of a Bachelor of Science in
Civil engineering. The main aim of the training program was to expose students to a more
practical approach of theoretical concepts learnt at the university
This report depicts the activities carried out during my nine weeks, during the internship period
from 8th
/June to 8th
/August 2015 on the Nansana-Busunju (47.6 km) road rehabilitation project
under UNRA (client). The project was contracted by Spencon Services limited and supervised by
MBW consulting limited with China Wu Yi Ltd as the sub contractor.
This report involves details of all the activities I was involved in during the internship period.
These have been separated into two sections namely; Road conditional surveying and material
testing
Road conditional surveying spanned a period of two weeks of the industrial training from
8th
/June to 19th
/June 2015.
Conditional surveying involved the visual surveying/inspection carried out on the projected road
location, including observation, analysis and recording data pertaining to the conditional status of
features along the existing right of way prior to rehabilitation. This information was analysed to
ascertain how these features would affect the rehabilitation process of the road, changes
suspected and suggested. The features observed included status and design of drainage
structures, carriageway and roadway status, road furniture. The data recorded at every section
was recorded and compiled in a results table from which a report to describe the conditional
status of the road could easily be determined at each chainage as required. This would further
help the design engineer in making any design decisions
Material testing spanned a period of seven weeks of the industrial training from 22nd
/June to
8th
/August 2015.
The material tests carried out during my internship period were predominantly based on the
existing pavement material, to determine the physical and chemical properties in order to
determine how best to utilize the existing material, and otherwise, how to modify it for proper
usage in the pavement reconstruction. We carried out tests both insitu and in the laboratory like
grading, CBR test, relative compaction, DCP insitu test, atterberg/consistency limit tests,
modified proctor test, specific gravity and water absorption determination tests on coarse and
fine aggregates. These tests created an insight on the nature of soils and materials involved in the
rehabilitation process, and the data from each of the tests was analysed appropriately to yield
information that is readily available to assist in the design process of the projected road
I acquired information through practical involvement in site activities, technical assistance from
my field supervisor Eng. Robert K.Kakiiza, department supervisors, site engineers, technicians,
foremen, photography and videography, reading relevant available literature about the project
and activities.

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page v
TABLE OF CONTENTS
DECLARATION .................................................................................................................... i
DEDICATION....................................................................................................................... ii
ACKNOWLEDGEMENTS................................................................................................... iii
ABSTRACT.......................................................................................................................... iv
TABLE OF CONTENTS ........................................................................................................v
LIST OF FIGURES.............................................................................................................. vii
LIST OF TABLES ................................................................................................................ ix
LIST OF GRAPHS ............................................................................................................... ix
ACRONYMS..........................................................................................................................x
CHAPTER One. INTRODUCTION.........................................................................................1
1.0 Background.......................................................................................................................1
1.1 Objectives .........................................................................................................................1
1.2 Project setting....................................................................................................................1
1.2.1 Background of MBW consulting limited.....................................................................2
1.2.2 Sign board ..................................................................................................................2
1.2.3 Project organizational structure...................................................................................3
1.3 Training activities..............................................................................................................5
1.4 Scope ................................................................................................................................5
1.4.1 Conditional road assessments .........................................................................................5
1.4.2 Materials testing .............................................................................................................5
1.5 Report writing ...................................................................................................................6
CHAPTER Two. ROAD CONDITIONAL SURVEYING........................................................7
2.0 Introduction.......................................................................................................................7
2.1 Tools used .........................................................................................................................7
2.2 Right of way......................................................................................................................8
Carriageway width ..............................................................................................................8
Shoulders ..........................................................................................................................12
Road furniture ...................................................................................................................15
2.3 Drainage structures..........................................................................................................16
Side trenches .....................................................................................................................17

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page vi
Culverts.............................................................................................................................18
2.4 Culvert design .................................................................................................................23
Culvert cross-section .........................................................................................................24
Culvert inlet/ outlet............................................................................................................24
Conclusion ........................................................................................................................25
CHAPTER Three. MATERIALS TESTING...........................................................................26
3.1 Introduction.....................................................................................................................26
3.2 Tests on existing base material ........................................................................................26
3.2.1 Sampling of test samples...........................................................................................26
3.2.2 Moisture content test.................................................................................................27
3.2.3 Particle size distribution (wet sieving).......................................................................28
3.2.4 Modified proctor test ................................................................................................34
3.2.5 California bearing ratio test (CBR)............................................................................39
3.2.6 Dynamic cone penetrometer (DCP) test ....................................................................45
3.2.7 Atterberg limit testing...............................................................................................48
3.2.7.1 Liquid limit test (Cone Penetrometer Method) .......................................................48
3.2.7.2 Plastic limit test .....................................................................................................51
3.2.7.3 Linear shrinkage determination test........................................................................53
3.3 Tests on aggregates..........................................................................................................55
3.3.1 Sieve analysis test.....................................................................................................55
3.3.2 Flakiness index test...................................................................................................60
3.3.3 Specific gravity and water absorption test for coarse aggregates................................63
3.3.4 Specific gravity and water absorption test for fine aggregates ...................................66
3.4 Insitu tests .......................................................................................................................69
3.4.1 Field density test by sand replacement method..........................................................69
CHAPTER Four. APPRECIATION, CHALLENGES AND CONCLUSIONS .......................74
4.0 Achievements..................................................................................................................74
4.1 Challenges faced and suggested solutions;.......................................................................74
4.1.1 By the internship trainee ...........................................................................................74
4.1.2 By the contractor ......................................................................................................75
4.3 Conclusion ......................................................................................................................76

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page vii
REFERENCES .........................................................................................................................77
LIST OF FIGURES
Figure 1.1: Sign board.................................................................................................................3
Figure 1.2: Site organizational structure ......................................................................................4
Figure 2.1: Equipment for Road inspection .................................................................................8
Figure 2.2: Carriageway status ..................................................................................................10
Figure 2.7: Shoulder status........................................................................................................14
Figure 2.10: Shoulder status......................................................................................................15
Figure 2.11: Road furniture .......................................................................................................16
Figure 2.12: Drainage trench .....................................................................................................17
Figure 2.13: Cross culverts........................................................................................................18
Figure 2.14: Access culvert .......................................................................................................19
Figure 2.15: Concrete culvert ....................................................................................................20
Figure 2.16: Steel culvert ..........................................................................................................21
Figure 2.17: Culvert shapes.......................................................................................................22
Figure 2.18: Culvert sizes..........................................................................................................22
Figure 2.19: Culvert barrels.......................................................................................................23
Figure 2.20: Culvert cross-section .............................................................................................24
Figure 2.21: Culvert outlet/inlet.................................................................................................25
Figure 3.1: Field base material sampling ...................................................................................27
Figure 3.2: Gradation test equipment.........................................................................................29
Figure 3.3: Sample washing ......................................................................................................30
Figure 3.4: Washed sample .......................................................................................................30
Figure 3.5: Sieve setup..............................................................................................................31
Figure 3.6: Proctor test equipment.............................................................................................35
Figure 3.7: Moisturizing the sample ..........................................................................................36
Figure 3.8: Greasing the mould .................................................................................................36
Figure 3.9: Hand ramming in layers ..........................................................................................37
Figure 3.10: Weighing the mould ..............................................................................................37
Figure 3.11: Removing sample from mould...............................................................................38
Figure 3.12: Removing sample to determine moisture content...................................................38
Figure 3.13: Rifling the sample .................................................................................................41

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page viii
Figure 3.14: Preparing mould samples for CBR test ..................................................................41
Figure 3.15: Preparing mould samples for soaking ....................................................................42
Figure 3.16: Soaking mould samples.........................................................................................42
Figure 3.17: Draining soaked mould samples ............................................................................43
Figure 3.18: Penetrating mould samples ....................................................................................44
Figure 3.19: Force and penetration dial gauges..........................................................................44
Figure 3.20: Casing for DCP test equipment..............................................................................46
Figure 3.21: Setting up instrument.............................................................................................46
Figure 3.22: Equipment for cone penetrometer test....................................................................49
Figure 3.23: Crashing soil particles ...........................................................................................49
Figure 3.24: Cone penetrometer ................................................................................................50
Figure 3.25: Plastic limit test sample .........................................................................................52
Figure 3.26: Prepared samples for shrinkage test.......................................................................54
Figure 3.27: Linear shrinkage samples out of the oven ..............................................................54
Figure 3.28: Kakiri stone quarry, aggregate sampling................................................................56
Figure 3.29: Sampling aggregates in bags..................................................................................56
Figure 3.30: Sample rifling........................................................................................................57
Figure 3.31: Aggregate sieving..................................................................................................58
Figure 3.32: Hand sieving .........................................................................................................58
Figure 3.33: Flakiness index gauge............................................................................................61
Figure 3.34: Non flaky aggregates retained on gauge.................................................................62
Figure 3.35: Sieving soaked aggregates through a 4.75mm sieve...............................................64
Figure 3.36: Drying aggregates with towels...............................................................................64
Figure 3.37: Weighing aggregates wholly immersed in water....................................................65
Figure 3.38: Drying aggregates with hair dryer..........................................................................67
Figure 3.39: Aggregates slump intact, wetter than SSD state .....................................................67
Figure 3.40: Aggregates slump just failed, SSD condition present .............................................68
Figure 3.41: Excavating and sampling sand for field density test ...............................................70
Figure 3.42: Drying washed sand ..............................................................................................71
Figure 3.43: Determining density of sand with sand pouring cylinder........................................71
Figure 3.44: Trial section to be tested for density ......................................................................72
Figure 3.45: Excavating hole for testing ....................................................................................72
Figure 3.46: Sand replacement in excavated hole ......................................................................73

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page ix
LIST OF TABLES
Table 2.1: Carriageway conditional status ...................................................................................9
Table 2.2: Shoulders' conditional status.....................................................................................13
Table 2.3: Drainage structures...................................................................................................17
Table 2.4: Concrete culverts; Pros and cons...............................................................................20
Table 2.5: Steel culverts; Pros and cons.....................................................................................21
Table 3.1: Sieve analysis CH 23+500........................................................................................33
Table 3.2: DCP test results; raw data.........................................................................................47
Table 3.3: Sieve analysis Kakiri stone quarry sample ................................................................59
LIST OF GRAPHS
Graph 3.1: Gradation analysis ...................................................................................................32
Graph 3.2: Sieve analysis chart..................................................................................................34
Graph 3.3: Proctor curve ...........................................................................................................39
Graph 3.4: Sieve analysis curves ...............................................................................................60

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page x
ACRONYMS
1. PVC ---- Polyvinyl Chloride
2. HDPE ---- High Density Poly-Ethylene
3. CBR ---- California Bearing Ratio
4. DCP ---- Dynamic Cone Penetrometer
5. UNRA ---- Uganda National Roads Authority
6. CH ---- Chainage
7. P.I ---- Plasticity Index
8. P.L ---- Plastic Limit
9. L.L ---- Liquid Limit
10. S.L ---- Shrinkage Limit
11. CRR ---- Crushed Run Rock
12. F.I ---- Flakiness Index
13. LHS ---- Left hand Side
14. RHS ---- Right Hand Side
15. MDD ---- Maximum Dry Density
16. OMC ---- Optimum Moisture Content
17. SSD ---- Saturated Surface Dry
18. ASTM ---- American Society for Testing and Materials
19. BS ---- British Standards
20. IS ---- International Standards

KAGANZI KENBERT 2ND YEAR INTERNSHIP REPORT Page 1
CHAPTER One. INTRODUCTION
This report includes a technical account of the activities I participated in during my nine week
long industrial training. The information in this report is based on my personal observations,
experience during participation in site activities, consultation and the theoretical background
obtained from the lecture rooms.
1.0 Background
Industrial training is an important part of training to students especially the engineering student
since it prepares the student for real work in the field.
This course introduces students to various technological skills in industries and provides on-the-
job training and exposure. It’s through this kind of training that the student is exposed to the real
application of the theoretical knowledge from the classroom to the field.
1.1 Objectives
 Expose students to practical aspects of engineering and construction activities
 Provide an opportunity to students to relate the knowledge obtained during lectures to
actual field operations
 Create an understanding of the roles played by different project personnel during project
execution
 Enable students learn how to work in a team (casual workers, technicians, engineers, etc).
 Teach students different engineering ethics necessary for career building
 Enhance problem solving capacity of the students using available appropriate technology
and surrounding condition
 Enable students to have a hands-on with tools and equipment not readily available in the
University laboratories and are of great importance in the engineering field
 Enable students appreciate various challenges faced in the field and critical areas
necessitating further research studies.
1.2 Project setting
The project ongoing is “The Rehabilitation of National roads (6 Lots); Lot 4: Nansana-
Busunju Road; Procurement Reference No: UNRA/WORKS/2013-14/00025/01/04”
The contract agreement was made on the 6th
January 2015 from a bid made on 16th
May 2014
between the Uganda National Roads Authority and M/S Spencon Services Limited (Main
contractor) and China Wu Yi (Sub contractor) with an assigned duration of 20 months.

1.2.1 Background of MBW consulting limited
MBW Consulting limited is a leading engineering and infrastructure development consultancy
firm with over 50 years of experience in, planning, design and implementation of Civil
engineering projects in Uganda with expertise in; transportation, water supply system design and
sanitation engineering, structural and civil works, materials and geotechnical investigations.
Location
MBW Consulting Limited Head offices
Plot 107, Kiira Road
Kamwokya
Kampala P.O Box 84 Uganda
Other projects handled and supervised by MBW consult:
1. Upgrading works for 6 road links (Soweto, Salaama, Kimera, Kalerwe, Ttula, Kawempe-
Mpererwe and Bukoto-Kisaasi)from gravel to bitumen standard
2. Lubigi channel drainage improvement
Details about the project are indicated technically with the use of a designed sign board and
structure below
1.2.2 Sign board
The sign board is a structure installed at a given project site for public convenience to provide
information about the project. Refer to figure 1.1 below;

Figure 1.1: Sign board
1.2.3 Project organizational structure
This describes the structure and organization of the departments involved in the work on site, the
individuals’ in charge and the assistants present. The organizational structure at our site can be
seen in figure 1.2.below;

Figure 1.2: Site organizational structure

1.3 Training activities
I carried out my training on Rehabilitation of selected national roads 6-Lots Nansana-Busunju
(47.6km) project from 8th
/June to 8th
/August 2015. Wherein I was involved in two major
departments;
 Road conditional survey 8th
/June – 19th
/June 2015
 Materials laboratory testing 22nd
/June – 8th
/August 2015
My main site supervisor was Eng. Kakiiza Robert Kagaba (Deputy resident Engineer/
Measurement Engineer), also assisted by Mr. Balyogera Godfrey (Road Inspector).
The project was just in its initial stages that involved predominantly design and planning
strategies, with the main work station at the site offices and in the laboratory both located at CH
17+200 offset 25m R.H.S in Kakiri.
1.4 Scope
My internship training involved two major activities, conditional road assessment and materials
testing.
1.4.1 Conditional road assessments
This department was headed by the road inspector Eng. Balyogera Godfrey.
It involved analyzing the status of the existing road to undergo rehabilitation.
Major concern lay on the status of road features like the status of the existing carriageway,
roadway width, side drains, cut and fill sections, road furniture and the trading centers along the
entire length of the road.
This assessment was done to obtain statistics on the condition of these features mentioned, and
decide if they are still operational or have failed.
On ascertaining these facts, suggestions about the probable reasons of failure would be required.
A suitable remedy for the existing failed sections would then be suggested.
This would involve whether failed systems required either repair, or complete replacement. This
was majorly done to minimize costs of fixing failed systems along the road.
Areas along the road that were lacking certain essential features were also suggested in a final
report in order to facilitate efficient design of the road to be put up.
1.4.2 Materials testing
This department was headed by the materials engineer Eng. Okot Wilson and supervised by the
materials technician Mr. Balenzi Enock.
Tests in this department were mainly done on the existing pavement material and on sample of
material to be used in the construction of projected road features such as pavement layers, and
other road structures like concrete structures, and other road features.

Tests done were done in accordance to suitable specifications and the results analysed, and
scrutinized in order to ascertain whether the materials meet the required standards as per the
specifications.
Decisions were then made on whether the materials tested fit the design specifications of the
anticipated road, or if some modification was required.
1.5 Report writing
On carrying out these activities, I have written a detailed report involving all the technical
activities done and what I was able to learn within this period.
This report contains my personal assessment of the observations I made during the training, as
well as some additional conception and ideologies supplemented by the department trainers,
supervisors and any other officials that were in position to offer any help.

CHAPTER Two. ROAD CONDITIONAL SURVEYING
2.0 Introduction
Conditional surveying spanned a period of two weeks of the industrial training from 8th
/June to
19th
/June 2015.
Conditional surveying involved the visual surveying/inspection carried out on the projected road
location, including observation, analysis and recording data pertaining to the conditional status of
features along the existing right of road way.
This information was analysed to ascertain how these features would affect the rehabilitation
process of the road, changes suspected and suggested.
The features observed included status and design of drainage structures, carriageway and
roadway status, road furniture.
The data recorded at every section was recorded and compiled in a results table from which a
report to describe the conditional status of the road could easily be determined at each chainage
as required. This would further help the design engineer in making any design decisions.
2.1 Tools used
 Cameras
 Colored flags to control traffic shown in Figure 2.1C
 Reflector jackets in Figure 2.1B
 Wheel tape in Figure 2.1D, steel tape
Some of the tools applied can be seen in Figure 2.1 below

Figure 2.1: Equipment for Road inspection
2.2 Right of way
This refers to the width of land available for road. It is made up of the carriageway, shoulders,
road side structures and reservation allowance for future maintenance or expansion purposes.
Carriageway width
This refers to the width of the road including auxiliary lanes devoted to the use of vehicles.
Pavement failure
Pavement structural failure means the pavement has failed in a way that it is no longer able to
transmit wheel loading through the road fabric without causing further rapid deterioration of the
road pavement.
In this part dealing with assessing serviceability status, we looked out for the failed sections of
the carriageway, mode of failure and suggested probable reasons of failure, as well as solutions
to ensure durability on rehabilitation.
A B
C D

Table 2.1: Carriageway conditional status
CHAINAGE
FROM
TO
CONDITIONAL
STATUS
PROBABLE
CAUSE
SUGGESTED
REMEDY
CH 0+000
CH 1+200
 Slight alligator cracking
 Fatigue cracks in Figure
2.2B
 Potholes in Figure 2.2C
 Pavement settlement
Refer to figure 2.2 below
 Continuous pavement
vehicular loading and
unloading due to
constant heavy traffic
 Weak base
 Pavement replacement
from base.
 Stronger base design in
rehabilitation
 Adopting better base
stabilization techniques
CH 1+200
CH 6+000
 Many potholes and
patches present,
compromising road
aesthetics
 Rutting of pavement
 Pavement failure due to
a weak base
 Fatigue due to cyclic
loading
 Base repair with modified
stronger material
 Proper placement of asphalt
design specification
 Proper maintenance of
finished road
CH 6+000
CH 34+000
 Extreme pavement
failure
 Many Potholes
 Exposed base in Figure
2.4 C, D
 Pavement blowout in
some areas
 Extreme pavement
deformation in some
sections
 Poor drainage in some
sections in Figure 2.4 A,
B
 Heavy trucks’
predominant use
 Poor sub-base material
and construction
techniques
 Re-design and
reconstruction of pavement
and sub-grade stabilization
 Installation of weigh bridge
along the reconstructed
road
 Installation of efficient
drainage systems
CH 34+000
CH 48+185
 Carriage way was intact,
no significant failure in
this section
Refer to figure 2.5 and 2.6
below
 Presence of a strong
stone(CRR) base
 Only requires an overlay/
surface dressing, nominal
thickness 25 mm

Figure 2.2: Carriageway status

Shoulders
Shoulders refer to lane-like extensions installed on either side of the carriageway constructed
usually independent of the carriageway.
Shoulders are available for the purposes to:
 Support and protect the carriageway from damage, by taking up any initial failure starting
from the outer sides of the road width.
 Provide space for a vehicle to stop or park off the carriageway when necessity arises.
 Act as driveway for cyclists.
 Walkway for pedestrians in cases where no sidewalks have been availed for pedestrian
use.
 Move water away from roadway before it can infiltrate road’s sub-base.
Shoulder inspection
Here we observed the status of the existing shoulders, mode of failure and remedy to enable
construction of a high class road.

Table 2.2: Shoulders' conditional status
CHAINAGE
FROM
TO
CONDITIONAL
STATUS
PROBABLE
CAUSE
SUGGESTED
REMEDY
CH 0+000
CH 6+000
 Shoulder-carriageway
bond was intact
 Shoulders were intact
 Failure/breaking had
started for shoulders on
RHS
 Uniform base for
carriageway and
shoulder
 Absence of drainage
systems on the RHS
 Installation of drainage
systems on RHS to prevent
shoulder erosion
CH 6+000
CH 34+000
 Shoulders broken starting
at shoulder-carriageway
intersection
 Shoulders were broken
from ends, some totally
broken and disappeared in
some sections exposing
carriageway
 Shoulders some sections
were buried in silt deposits
and vegetation
 Absence of demarcation to
indicate shoulder start
Refer to figure 2.8 and 2.9
below
 Variation in
underlying base
material between
carriageway and
shoulder
 Weak base material
underlying shoulders
 Poor drainage systems
in some sections
 Use of strong underlying
base material for shoulders
to improve their durability
 Periodic maintenance to
prolong shoulder
operational duration
CH 34+000
CH 48+185
 Most sections shoulders
intact
 Absence of demarcation to
mark shoulder start
 Steep shoulder end run off
which is dangerous and
mechanically problematic
for motorists and cyclists
 Strong uniform stone
base underlying
shoulders
 Absence of proper
drainage runoff
systems
 Painting end of lane to
avoid motorists overly
unsettling shoulder users
 Proper drainage systems to
drive water off shoulders
without eroding ends
should be applied

Figure 2.7: Shoulder status

Road furniture
Road furniture refers to structures such as road signs, street lights placed along the road for the
benefit of the public.

Figure 2.11: Road furniture
During our inspection, most road symbols had failed, by either peeling of their posts or broken
and required replacement. Also, some locations were identified lacking and required furniture,
such as for humps in trading centers. Refer to the figure 2.11 above.
2.3 Drainage structures
Drainage structures on a highway are designed to ensure that precipitation is removed from the
pavement as soon as possible. It includes bridges, culverts, mitre drains (offshoots), side trenches
and all other systems designed to drain water from the pavement.
Along our highway, we observed a number of both operational and many non functional culverts
box and pipe culverts. There were no bridges originally constructed along the road.
The main difference between a bridge and a culvert is the size.
The differences between a bridge and culvert are shown in table 2.3 below:

Table 2.3: Drainage structures
BRIDGE CULVERT
 Cross-sectional size/ width of greater than
20ft
 Size less than20ft
 In most cases doesn’t have a floor, i.e. the
two piers/ abutments are not joined at the
bottom by a surface.
In some cases, Gabion mattresses are used
as a floor to avoid erosion
 Is lined with proper floor designed of
specific material depending on its function,
shape and size
 Is designed to allow easy passage of traffic
or community across obstacles like rivers,
valleys
 Made for passage of water from upstream
of run off towards the downstream either
crossing below a pavement or as side
drains (access)
Side trenches
These are structures excavated to a specified depth existing at the end of the shoulders to drain
runoff from the carriageway
Concern here was laid on the size of the trench, its current functionality and the nature of
material lining in the drain, whether stone pitched or concrete lined.
Trenches are lined to prevent erosion/ scouring of natural trench bed which is common in
unlined trenches. Lining material is usually chosen to be of high frictional resistance to retard
runoff and mitigate the adverse effects of runoff such as erosion, destruction of plants and
property, flooding.
An example of a trench damaged by scouring is shown in the figure 2.12 below
Figure 2.12: Drainage trench

Culverts
A culvert is a structure hydraulically designed to convey water runoff under a highway, railroad,
access road or any other embankment
Culverts are categorised following a number of criteria ranging from size, type, material, shape,
number of spans, bedding.
Type
Cross culvert
Cross culverts cross from one side of the roadway to another and carry water beneath the road.
Some of the existing road culverts are shown in figure 2.13 below.
Figure 2.13: Cross culverts
They can be valley or relief cross drains.
Valley cross-drain
This crosses from one end of the road to another at right angles to the centerline.
Relief cross-drain
This crosses from one end of the road to another, but is laid at an angle (45° usually) to the road
centerline.
Access culvert
Access culverts exist on one side of the road to drain water beneath roadway offset pathways or
for drainage purposes of society. Example of an existing access culvert is in the figure 2.14
below.

Figure 2.14: Access culvert
Material
Culverts are generally constructed out of concrete, steel (smooth/corrugated), aluminium or
plastic (PVC, HDPE).
Pipe material used in a project depends on as durability, structural strength, roughness, bedding
condition, abrasion and corrosion resistance, water tightness, cost, span, discharge, topography,
soil chemistry or climate.
Only the concrete and steel culverts were in use as observed during our inspection.
Concrete culvert
This is made of reinforced concrete material. It can be constructed and laid insitu, or precast in a
concrete manufacturing company, then transported to site for installation.
It was the most common type of culvert along the entire road for drainage due to the relatively
low cost of concrete. An example of an existing concrete culvert can be seen in figure 2.15
below.

Figure 2.15: Concrete culvert
Table 2.4: Concrete culverts; Pros and cons
Advantages Disadvantages
 Relatively cheap
 Are strong and durable
 Less durable under corrosive conditions
 Bulky and difficult during installation
Corrugated steel
This is made out of a single piece of galvanized steel corrugated into folds to provide a greater
strength to weight ratio compared to a smooth pipe.
It was less popular than the concrete culvert. An example of a corrugated metal culvert is shown
in the figure 2.16 below.

Figure 2.16: Steel culvert
Table 2.5: Steel culverts; Pros and cons
Advantages Disadvantages
 Quick installation and light weight
 Strong and can withstand heavy traffic
loading in shallow cover conditions
 Easy to do maintenance
 Expensive
 Prone to rusting and corrosion
Shape
There are a variety of culvert shapes that can be used depending on the drainage design in terms
quantity, speed, and resistance to flow. The culvert shapes present during our inspection were
 Box culvert in Figure 2.17A
 Circular culvert in Figure 2.17B
Figure 2.17 below shows an example of the different culvert shapes observed during the
inspection.

Figure 2.17: Culvert shapes
Size
The culvert size is determined by the projected dynamics of stream flow, and how flow changes
with seasons. Culverts are sized to handle peak flow, installed in a manner that will protect the
culvert’s strength over time.
The most popular circular culvert sizes were 600mmØ (Figure 2.18 C, D) and 900mØ (Figure
2.18 B) circular culverts.
Figure 2.18 below shows some of the different culvert sizes functioning along the existing road.
Figure 2.18: Culvert sizes

Number of barrels
Barrel as used in culvert discipline refers to the number of culvert pieces installed on one drain
location.
Culverts can either be of single span or multiple spans. Multiple span culverts are adopted to
avoid the high cost, transport and installation inconveniences caused by an alternative single
large width culvert.
The different existing barrel spans can be seen in figure 2.19 below.
Figure 2.19: Culvert barrels
Bedding
Bedding of a culvert refers to the thick concrete layer underlying a culvert. It’s mainly to protect
the culvert from corrosive action of elements seeping from soil layers below.
The material to be used in the bedding depends on the culvert type.
For the visible beddings, we observed concrete beddings had been used for the culverts.
2.4 Culvert design
Culvert installation involves excavation, bedding placement, culvert placement, back filling and
finishing. Finishing involves construction of outlet and inlet structures such as head wall, wing
wall, and apron.
These end structures are made out of masonry, or concrete.

Culvert cross-section
Figure 2.20 below can show how to determine the design parameters of the cross-section of a
culvert
Figure 2.20: Culvert cross-section
Calculating design parameters
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝐸𝑥𝑐𝑎𝑣𝑎𝑡𝑖𝑜𝑛 = 𝐷𝑒𝑝𝑡𝑕 𝑜𝑓 𝑒𝑥𝑐𝑎𝑣𝑎𝑡𝑖𝑜𝑛 × 𝑊𝑖𝑑𝑡𝑕 × 𝐿𝑒𝑛𝑔𝑡𝑕 𝑜𝑓 𝑐𝑢𝑙𝑣𝑒𝑟𝑡
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝐵𝑒𝑑𝑑𝑖𝑛𝑔 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙 = 𝐷𝑒𝑝𝑡𝑕 𝑜𝑓 𝑏𝑒𝑑𝑑𝑖𝑛𝑔 × 𝑊𝑖𝑑𝑡𝑕 × 𝐿𝑒𝑛𝑔𝑡𝑕 𝑜𝑓 𝐶𝑢𝑙𝑣𝑒𝑟𝑡
𝑋𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑏𝑎𝑐𝑘𝑓𝑖𝑙𝑙 = 𝑋𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑒𝑥𝑐𝑎𝑣𝑎𝑡𝑖𝑜𝑛 − 𝐴𝑟𝑒𝑎 𝑜𝑓 𝑐𝑢𝑙𝑣𝑒𝑟𝑡
𝐴𝑟𝑒𝑎 𝑜𝑓 𝑐𝑢𝑙𝑣𝑒𝑟𝑡 =
𝜋𝐷2
4
𝑤𝑕𝑒𝑟𝑒 𝐷 − 𝐷𝑖𝑎𝑚𝑒𝑡𝑒𝑟 𝑜𝑓 𝑐𝑢𝑙𝑣𝑒𝑟𝑡
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑏𝑎𝑐𝑘𝑓𝑖𝑙𝑙 = 𝑋𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑏𝑎𝑐𝑘𝑓𝑖𝑙𝑙 × 𝐿𝑒𝑛𝑔𝑡𝑕 𝑜𝑓 𝐶𝑢𝑙𝑣𝑒𝑟𝑡
Culvert inlet/ outlet
Figure 2.21 below shows how to determine the design parameters of the culvert outlet

Figure 2.21: Culvert outlet/inlet
Calculating design parameters
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝐻𝑒𝑎𝑑 𝑊𝑎𝑙𝑙 = 𝐴 × 𝐵 − 𝐴𝑟𝑒𝑎 𝑜𝑓 𝐶𝑢𝑙𝑣𝑒𝑟𝑡 × 𝐻𝑒𝑎𝑑 𝑊𝑎𝑙𝑙 𝑇𝑕𝑖𝑐𝑘𝑛𝑒𝑠𝑠
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑊𝑖𝑛𝑔 𝑊𝑎𝑙𝑙 =
𝐶 + 𝐷
2
× 𝐸 × 𝑊𝑖𝑛𝑔 𝑊𝑎𝑙𝑙 𝑇𝑕𝑖𝑐𝑘𝑛𝑒𝑠𝑠
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝐴𝑝𝑟𝑜𝑛 =
𝐹 + 𝐺
2
× 𝐻 × 𝐴𝑝𝑟𝑜𝑛 𝑇𝑕𝑖𝑐𝑘𝑛𝑒𝑠𝑠
Conclusion
The design criteria form the basis of selection of the final design configuration. The design
involves determining different aspects of the culvert like size, shape, materials from which the
engineer makes constructive decisions.
Design of a culvert was mainly based on hydraulic efficiency, serviceability, structural stability,
economics, environmental considerations, traffic safety, and land use requirements.

CHAPTER Three. MATERIALS TESTING
3.1 Introduction
Material testing spanned a period of 7 weeks of the industrial training from 22nd
/June to
8th
/August
The material tests carried out during my internship period were predominantly based on the
existing pavement material, to determine the physical and chemical properties in order to
determine how best to utilize the existing material, and otherwise, how to modify it for proper
usage in the pavement reconstruction.
We carried out tests both insitu and in the laboratory like: grading, CBR test, relative
compaction, DCP insitu test, atterberg/consistency limit tests, modified proctor test, specific
gravity and water absorption determination tests on coarse and fine aggregates.
These tests created an insight on the nature of soils and materials involved in the rehabilitation
process, and the data from each of the tests was analysed appropriately to yield information that
is readily available to assist in the design process of the projected road.
3.2 Tests on existing base material
3.2.1 Sampling of test samples
Samples to undergo laboratory testing were obtained from the existing base layers of the existing
road pavement, collected at 1km intervals in order to obtain a uniform analysis of results along
the entire length of the road.
The sampling process involved:
 Stripping off of the surfacing layer
 Excavation of pavement layer to a depth of up to 100mm over an area of about 1m2
.
 The material excavated was then transferred to a sampling bag with the use of a shovel,
the sample labeled with the sample number, chainage, location, and material type.
 Transportation of the material to the laboratory.
Figure 3.1 below shows how an existing base material sample can be collected for testing.

Figure 3.1: Field base material sampling
3.2.2 Moisture content test
Objective
The main objective is to determine the amount of water present in a soil sample as expressed as a
percentage of the mass of dry soil.
Principle
The moisture content of a soil sample is assumed to be the amount of water within the pore space
between the grains which is removable by a standard laboratory procedure of oven drying at a
temperature of 105-110ºC.
References
BS 1377: Part 2: 1990
Equipment
 Drying oven
 Weighing balance (4.5kgs, 0.1g accuracy)
 Metal container
Test procedure
The container was cleaned and dried, and then weighed on the balance to the nearest 0.1g (M1)
A representative sample was placed on the container and the container immediately weighed
(M2)

The container was then placed in the oven to dry at 105ºC for 24hours
The container was then weighed after drying and mass recorded (M3)
Analysis of results
Moisture content was then calculated from the formula:
𝑀𝑜𝑖𝑠𝑡𝑢𝑟𝑒 𝐶𝑜𝑛𝑡𝑒𝑛𝑡 =
𝑀2 − 𝑀3
𝑀3 − 𝑀1
Where M1- Mass of container alone
M2- Mass of container and wet soil
M3- Mass of container and dry soil
3.2.3 Particle size distribution (wet sieving)
Objective
Particle size distribution analysis is carried out especially on coarse soils to present the relative
portions of different sizes of particles, from which it is possible to classify the soil as consisting
of predominantly gravel, sand, silt or clay.
Principle
This procedure involves preparation of the sample by wet sieving to remove silt sized particles,
followed by dry sieving of the remaining coarse material.
References
BS 1377: Part 2: 1990
Equipments
 Test sieves 75mm, 50, 37.5, 28, 20, 14, 10, 5, 2, 1.18, 0.475, 0.3, 0.075mm.
 Lid and receiver pan
 Weighing balance (30kgs, 1g accuracy)
 Riffle boxes
 Oven
 Metal trays
 Sieve brushes
 Water source
Some of the equipment used can be seen in figure 3.2 below.

Figure 3.2: Gradation test equipment
Sample preparation
The test sample obtained from the field was air-dried for 12 hours.
The sample was then quartered through rifle boxes to obtain a representative sample which was
weighed and placed on large metal tray.
Water was then added to the sample on the tray and the sample soaked for 12 hours to eliminate
any agglomeration by fine particles.
The soaked sample was then washed thoroughly through a 75µm sieve to remove the silt
material. A 2mm sieve is placed above the 75µm sieve to act as a guard sieve.
Caution was taken not to lose any material overflowing the sieves.
Refer to figure 3.3

Figure 3.3: Sample washing through 0.075mm sieve
All the material retained on the 75µm was transferred to a tray and placed in the oven to dry for
24 hours at 105ºC.
Refer to figure 3.4 for a thoroughly washed sample ready for oven drying.
Figure 3.4: Washed sample
Test procedure
The sample was taken out of the oven and left to cool for some time.
The sieves were then stacked up in order of decreasing aperture size going down, and the
receiver placed at the bottom.
Refer to figure 3.5 below.

Figure 3.5: Sieve setup
The sample was then weighed and poured onto the top sieve and the lid placed on top.
The sieve set up was then agitated vigorously, and the mass retained on each sieve weighed and
recorded.
A sieve brush was used to ensure all material retained on sieves was removed for weighing.
Analysis of results
The results obtained were used to draw a graph of cumulative percentage mass passing against
sieve-aperture size.
The graph was then analysed to determine the gradation of the sample under test as follows:
Refer to graph 3.1.

Graph 3.1: Gradation analysis
Source: Martin Rodgers 1988. Highway Engineering. Blackwell Science

Table 3.1: Sieve analysis CH 23+500
LOCATION: CH 23+500 LHS
MATERIAL: EXISTING BASE
WET MASS: 4703g
DRY MASS: 4115g
MOISTURE CONTENT: 14.29%
SIEVE
SIZE
(mm)
MASS
RETAINED
(g)
CUMULATIVE
MASS
RETAINED (g)
CUMULATIVE
MASS PASSING
(g)
PERCENTAGE
PASSING (%)
75 0 0 4113 100.00
50 0 0 4113 100.00
37.5 198 198 3915 95.19
28 316 514 3599 87.50
20 731 1245 2868 69.73
14 890 2135 1978 48.09
10 916 3051 1062 25.82
5 415 3466 647 15.73
2 396 3862 251 6.10
1.18 110 3972 141 3.43
0.475 75 4047 66 1.60
0.3 31 4078 35 0.85
0.075 27 4105 8 0.19
Pan 8 4113 0 0.00
TOTAL 4113

Graph 3.2: Sieve analysis chart
3.2.4 Modified proctor test
Objective
The objective was to obtain relationships between compacted dry density and soil moisture
content. This test was done to provide a guide for specifications on field compaction.
Principle
The dry density that can be achieved for a soil depends on the degree of compaction applied and
the moisture content.
The moisture content which gives the highest dry density is called the optimum moisture content
for that type of compaction.
References
BS 1377: Part 4: 1990
Equipment
 Cylindrical compaction mould internal diameter 105mm, height 115mm, and volume
1000cm3
 Base plate and mould extension collar
 Metal rammer 4.5kgs weight, with drop of 450mm
0.00
20.00
40.00
60.00
80.00
100.00
120.00
0.01 0.1 1 10
PrcentageFiner(%)
Sieve size 'log' (mm)
GRADATION CHART
CH 23+500 LHS

 Straight edge
 Measuring cylinder
 20mm test sieves
 Rifle boxes
 Weighing balance 30kg, accuracy 1g
 Metal pans, and large trays
 Distilled water
 Scoop
 Apparatus for moisture content determination
Some of the equipment used for the test can be seen in figure 3.6.
Figure 3.6: Proctor test equipment
Sample preparation
The air dried material from the field was sieved through a 20mm test sieve and the material
passing quartered using rifle boxes
5 representative samples were then prepared each about 3kg
Each sample was mixed with different amounts of water to give a suitable range of moisture
contents, using a measuring cylinder. Refer to figure 3.7.

Figure 3.7: Moisturizing the sample
Each of the 5 portions were then placed in airtight containers and allowed to cure for about
2hours.
Test procedure
The mould with the base plate attached was weighed to the nearest 1g, the extension collar
attached and then placed on a concrete floor.
The inner surface of the mould was greased with a thin layer of oil to prevent soil from sticking
to the sides. Refer to figure 3.8 for an example of a mould being greased.
Figure 3.8: Greasing the mould
A quantity of moist soil was placed in the mould up to about 1/3 of the mould’s height.
The rammer was then raised to the top of the guide, the handle released and left to drop freely
onto the sample. Figure 3.9 shows a sample being compacted in layers.

Figure 3.9: Hand ramming in layers
The process was repeated in a different position on the sample, and then again systematically
covering the entire surface of the sample. This was done until a total of 62 blows was achieved
The rammer was then removed and the next layer of soil filled in the mould. The above process
was repeated four times more by applying 62 blows of the rammer to each layer. The mould was
filled with surface not more than 6mm proud of the upper edge of the mould
With all the 5 layers compacted, the extension collar was removed; excess soil struck off and
surface levelled using a straight edge. Any coarse particles removed in the leveling process were
replaced by finer material from the sample well pressed in.
The mould containing the soil, with the base plate still attached were weighed
Refer to figure 3.10.
Figure 3.10: Weighing the mould
The compacted sample from the mould was then removed and a representative sample taken off
for determination of moisture content. Refer to figure 3.11 and 3.12 below.

Figure 3.11: Removing sample from mould
Figure 3.12: Removing sample to determine moisture content
The remaining portion of the sample was discarded
The entire process was carried out for all five portions of the sample
Analysis of results
1. Bulk density is calculated from the following formula;
𝐵𝑢𝑙𝑘 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 𝜌 =
𝑀2−𝑀1
𝑉
× 1000 (𝑘𝑔/𝑚3
)
Where M1- Mass of mould and base plate (g)
M2- Mass of mould, base plate and compacted soil (g)
V- Volume of the mould (cm3
)
2. The dry density was then calculated from the formula;
𝐷𝑟𝑦 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 𝜌 𝑑 =
100𝜌
100 + 𝑤
Where w is the Moisture Content of the soil (in %)
𝜌 is the bulk density (in kg/m3
)
3. A graph of dry densities was then plotted against corresponding moisture contents. A
curve of best fit was then drawn from which the maximum dry density and optimum
moisture content values were read off. Refer to graph 3.3 below.
4.

Graph 3.3: Proctor curve
Conclusion
The values obtained from the tests are used to ascertain the optimum moisture content, which is
the required amount of water applied to soils to be compacted in the base layer to achieve
maximum density, strength and bearing capacity.
3.2.5 California bearing ratio test (CBR)
Objective
The strength of the subgrade is the main factor in determining the required thickness of flexible
pavements for roads. Strength of pavement layers is expressed in terms of the California Bearing
Ratio value.
Thus it is a predominant requirement in the design for pavement materials of natural gravel.

Principle
The CBR value is the resistance to a penetration of 2.5mm of a standard cylindrical plunger of
50mm diameter, expressed as a percentage of the known resistance of the plunger to 2.5mm in
penetration in crushed aggregate.
References
BS 1377: Part 4: 1990
Equipment
 Test sieve 20mm
 Rifle boxes
 Measuring cylinder
 Metal trays
 Air tight polythene
 Soaking tank
 Cylindrical metal mould, with detachable perforated and solid base plate, removable
extension
 Swell plate, surcharge discs, tripod to support dial gauge
 Steel rod
 Grease/ oil
 Straight edge
 Balance (30kg, 1g accuracy)
 Apparatus for moisture content
 Filter papers 150mm diameter
 CBR compression machine
 Stop watch/ timer
Sample preparation
Air dried field material passing a 20mm sieve was quartered with rifle boxes to eliminate sample
segregation
Figure 3.13 below shows an example of a sample being rifled.

Figure 3.13: Rifling the sample
The sample was then brought to the required moisture content, chosen to represent the design
conditions for which results are required, most preferably the earlier attained optimum moisture
content. The sample was then thoroughly mixed and sealed in an airtight container for overnight
to ensure proper and uniform water saturation
The wet samples kept overnight were then divided into three portions each 6kg and each covered
with an airtight polythene to prevent moisture loss
The mould assembly was set up on a solid base, inner surfaces oiled and a sample added and
compacted;
Sample 1 each layer compacted with 62 blows of the 4.5kg rammer in 5 layers
Sample 2 was compacted with 30 blows of the 4.5kg rammer within 5 layers
Sample 3 was compacted with 62 blows of 2.5kg rammer within 3 layers
Refer to figure 3.14 for compacted mould samples ready for soaking.
Figure 3.14: Preparing mould samples for CBR test
The tops were then levelled off with a straight edge and the weights recorded.

Soaking
The base plates were then replaced with perforated base plates with filter papers on both ends of
compacted soil. The collar was also screwed, packing joints with jelly to obtain a watertight
joint.
They were then placed in the empty soaking tank, perforated swell plate added, and annular
surcharge discs fitted together around the stem on the perforated plate
Dial gauge was mounted on top the extension collar, kept in place with the tripod, and reading
adjusted to zero to measure the swell
Figure 3.15 shows an example of soaked mould samples.
Figure 3.15: Preparing mould samples for soaking
Soaking tank was then filled with water to just below the top of the mould extension collar and
the timer started just when the water has covered the base plate.
Figure 3.16: Soaking mould samples
Readings of the dial gauge were recorded daily for the next four days
The dial gauge was then taken off its support, mould assembly removed from soaking tank
The surcharge discs, perforated plate were removed and sample allowed to drain for 15minutes
Refer to figure 3.17 below.

Figure 3.17: Draining soaked mould samples
The extension collar was then removed and the perforated base plate refitted with the solid base
plate
The sample was trimmed level with the end of mould if it had swollen
Penetration test procedure
Mould with base plate was placed centrally on lower platen of testing machine with top surface
of sample exposed
Surcharge discs up 5kg weight were placed on top of sample
The cylindrical plunger was fitted into place on surface of sample
A seating force of 50N was applied to plunger, and the loading ring reading reset to zero
The dial gauge was also secured in position and its initial reading set to zero
The machine was turned on and plunger allowed to penetrate sample at a uniform rate of
1mm/min
Figure 3.18 below shows an example of sample penetration.

Figure 3.18: Penetrating mould samples
Readings on the force gauge were recorded at intervals of 0.25mm penetration up to 7.5mm
penetration
Figure 3.19: Force and penetration dial gauges
The plunger was then raised, the surface levelled by filling the depression left the plunger with
some soil
The base plate was then removed from lower end of the mould, fitted onto the top end and the
mould was inverted
The penetration test was repeated for this end and the recordings taken
A sample was then taken to obtain the moisture content

The penetration test was performed on all the three samples
Analysis of results
Results were analysed in excel by drawing a penetration curve of the force value against
penetration which brings out a normally upward convex curve.
Penetrations of 2.5mm and 5.0mm are used for calculating the CBR value, force values were
read off the on the force value axis on the curve
𝐶𝐵𝑅 𝑣𝑎𝑙𝑢𝑒 = 𝑃1 ×
100
13.2
% 𝑤𝑕𝑒𝑟𝑒 𝑃1 𝑖𝑠 𝑝𝑙𝑢𝑛𝑔𝑒𝑟 𝑓𝑜𝑟𝑐𝑒 𝑘𝑁 𝑎𝑡 2.5𝑚𝑚 𝑝𝑒𝑛𝑒𝑡𝑟𝑎𝑡𝑖𝑜𝑛
𝐶𝐵𝑅 𝑣𝑎𝑙𝑢𝑒 = 𝑃2 ×
100
20.0
% 𝑤𝑕𝑒𝑟𝑒 𝑃2 𝑖𝑠 𝑝𝑙𝑢𝑛𝑔𝑒𝑟 𝑓𝑜𝑟𝑐𝑒 𝑘𝑁 𝑎𝑡 5.0𝑚𝑚 𝑝𝑒𝑛𝑒𝑡𝑟𝑎𝑡𝑖𝑜𝑛
The higher of these two values was taken as the CBR value.
The results obtained for the other end of the sample are analysed with the same steps as done
with the calculation procedure above.
Conclusion
The higher the CBR rating, the harder the pavement layer, thus the greater the bearing capacity
of the road
High quality CRR has a CBR of over 80. The standard material for this test is crushed California
limestone which has a value of 100.
3.2.6 Dynamic cone penetrometer (DCP) test
Objective
To determine the mechanical properties of existing pavement layers for use in structural
pavement design and to provide a measure of a material’s insitu resistance to penetration.
Principle
The underlying principle of the DCP is that the rate of penetration of the cone, when driven by a
standard force, is inversely proportional to the strength of the material for example in the CBR
test. Where the pavement layers have different strengths, the boundaries between the layers can
be identified and the thickness of the layers determined
Reference
BS 5930:1999
Equipment
 DCP machine
Bottom rod, top rod (hammer shaft), falling hammer (8kgs falling through 575mm),
meter rule, 60° cone.
Refer to figure 3.20 for DCP apparatus.
 Road safety wear and equipment for traffic control

Figure 3.20: Casing for DCP test equipment
Test procedure
The DCP machine was assembled appropriately with the cone firmly screwed to the bottom rod
with a spanner, and clamp ring was fastened using alley keys, the meter rule placed in position
and set up at the position where test was required
Refer to figure 3.21 below to show how DCP machine is set-up
Figure 3.21: Setting up instrument

The initial meter rule reading was recorded, the weight lifted till it touches the handle, and left to
fall freely along the hammer shaft onto the coupling to make the first blow
The depth achieved after a number of blows as read off the meter rule was recorded
10 or 5 blows were normally satisfactory for good quality strong layers
1 or 2 blows were appropriate on meeting fairly weaker subbase and subgrade layers
Analysis of results
DCP results were analysed using the UK DCP version 3.1 software. Raw data was entered into
the program and analysis done; this program was chosen because it automatically generates the
thickness of layers with uniform strength. A change in gradient indicates a point of change from
one layer to another. The graphs were used to ascertain the depth of layers with uniform
strengths by noting uniformity in gradient
Table 3.2: DCP test results; raw data
PROJECT NAME: NANSANA BUSUNJU 47.6KM
LOCATION: CH 25+300 RHS Offset 2m
TEST: DCP
CLIENT: UNRA
TESTING DATE: 25/06/2015
NO. OF
BLOWS
TOTAL
BLOWS
READING
(mm)
ABSOLUTE
DEPTH
(mm)
PENETRATION
RATE
(mm/blow)
0 0 45 0 0.00
20 20 78 33 1.65
20 40 152 74 3.70
20 60 243 91 4.55
20 80 392 149 7.45
20 100 565 173 8.65
10 110 663 98 9.80
10 120 745 82 8.20
10 130 828 83 8.30
10 140 910 82 8.20
5 145 945 35 7.00
Conclusion
From the test results, the larger the penetration rate (mm), the weaker the pavement layer present
in that region
A sudden change in the penetration rate value signifies arrival of the cone into a new layer in the
pavement
CBR values were evaluated using DCP results using the expression

log10 𝐶𝐵𝑅 = 2.48 − 1.057log10(𝑆𝑡𝑟𝑒𝑛𝑔𝑡𝑕)
3.2.7 Atterberg limit testing
3.2.7.1 Liquid limit test (Cone Penetrometer Method)
Objective
The liquid limit refers to the established moisture content at which soil passes from the liquid
state to the plastic state. It provides a means of identifying and classifying fine grained soils
especially when the plastic limit is also known.
Principle
The cone penetrometer was preferred to the Casegrande method as it is a static test depending on
soil shear strength, thus is considered more precise and accurate.
It was used to determine the liquid limit of a sample passing a 425µm test sieve based on
measurement of penetration into soil by a standardized cone.
References
BS 1377: Part 2: 1990
Equipment
 Test sieve 425µm
 Mallet hammer
 Airtight container/ polythene
 Flat glass plate
 Palette knives
 Stainless steel cone, 35mm long, angle 30º
 Cylindrical metal cup 55mm diameter, 40mm deep
 Damp cloth
 Apparatus to determine moisture content
 Wash bottle containing distilled water
 Straight edge
 Stopwatch
Refer to figure 3.22 below for some of the equipment required in the liquid limit testing.

Figure 3.22: Equipment for cone penetrometer test
Sample preparation
An air dried sample was sieved through a 425µm test sieve, a mallet hammer used to break up
the agglomerated particles, and the material retained was discarded
Figure 3.23: Crashing soil particles
Material was weighed and transferred to a glass plate, enough for both plastic limit and shrinkage
limit tests in addition, water added and mixed thoroughly with two palette knives until a
homogeneous paste was obtained
The paste was then placed in an airtight container and allowed to stand for 16-24 hours to enable
water permeate through the soil

Test procedure
The prepared sample was placed on the glass plate and remixed thoroughly, more distilled water
added where necessary to have the first reading about 15mm
A portion of the mixed soil was pushed into the cup using a palette knife taking care not to trap
air; the cup was also gently tapped against a firm surface to further eliminate air. Any excess soil
was levelled off with a straight edge
The penetration cone was locked in position of the cone just touching the soil surface, confirmed
by a slight movement of the cup (Refer to figure 3.24). The dial gauge initial reading was
recorded
Figure 3.24: Cone penetrometer
The cone was then released for about 5 seconds, and then locked in position. The reading on the
dial gauge was read off. The difference between the initial and final readings being the cone
penetration
The cone was lifted out and cleaned carefully
The soil in the cup was then transferred back to the glass plate after taking off some material to
determine the moisture content. The cup was then washed and dried
The test was repeated three more times, with further water increments such that penetration
values lie within a range 15mm-25mm
Analysis of results
The moisture content of each specimen was calculated from;
𝑀𝑜𝑖𝑠𝑡𝑢𝑟𝑒 𝑐𝑜𝑛𝑡𝑒𝑛𝑡 =
𝑀2 − 𝑀3
𝑀3 − 𝑀1
× 100 %
Where M1 is the mass of the container

M2 is the mass of the container and wet soil
M3 is the mass of the container and dry soil
The liquid limit of the soil sample was the moisture content corresponding to a cone penetration
of 20mm as interpolated from a graph of moisture content against cone penetration.
3.2.7.2 Plastic limit test
Objective
The plastic limit refers to the moisture content at which soil becomes too dry to be plastic.
It was to be used together with the liquid limit to determine the plasticity index, which would be
used to classify cohesive soils
The plasticity index is the range of moisture contents for which a soil is plastic, with the finer the
soil signifying a greater plasticity index
Principle
This method works following the principle that a soil sample at its plastic limit totally crumbles/
shears when rolled to a thickness of 3mm.
References
BS 1377: Part 2: 1990
Equipment
 Two glass plates, one for mixing and another for rolling threads
 Two palette knives
 Apparatus for moisture content determination
 Clean water
 A metal rod, 100mm long, 3mm diameter
Sample preparation
The plastic limit determination test was performed as a continuation of the liquid limit test, and
its test material was conveniently prepared as part of the liquid limit test
Test procedure
About 40g of soil paste was placed on the glass plate and was allowed to dry partially until it was
plastic enough to be shaped into a ball (Refer to figure 3.25).

Figure 3.25: Plastic limit test sample
The ball was moulded between the fingers and rolled between the palms of the hands until the
heat of the hands dried the soil sufficiently for slight cracks to appear on its surface
The sample was divided into sub samples to carry out separate determination on each portion
The soil was moulded between the fingers to equalize the distribution of moisture. A thread was
then formed between the first finger and the thumb of each hand
The soil thread was then rolled between the fingers and the surface of the glass plate, using
enough pressure to reduce the diameter of the thread to about 3mm, in forward and backward
movements of the hand
The rod was used to check the thickness of the rolled sample
The soil was then picked up, moulded between the fingers to dry it further, rolled into a thread
and rolled out again as specified above
The procedure was repeated until the thread sheared both longitudinally and transversely when
rolled to about 3mm diameter. This first crumbling point was the plastic limit of the sample
The crumbled pieces of soil were then transferred to a suitable container of known weight and
taken off for moisture content determination
The procedure above was then repeated for the other sub samples in order to make separate
determinations
Analysis of results
The moisture content of both samples were calculated, and if the results differed by more than
0.5%, the whole test was repeated.
Otherwise, the average of the two moisture contents was taken as the plastic limit rounded off to
the nearest whole number
Determination of the plasticity index
The plasticity index (P.I) defined as the difference between the liquid limit (WL) and the plastic
limit (WP) is calculated from the equation below:

𝑃. 𝐼 = 𝐿𝑖𝑞𝑢𝑖𝑑 𝑙𝑖𝑚𝑖𝑡 𝑊𝐿 − 𝑝𝑙𝑎𝑠𝑡𝑖𝑐 𝑙𝑖𝑚𝑖𝑡 𝑊𝑃 𝑇𝑜 𝑡𝑕𝑒 𝑛𝑒𝑎𝑟𝑒𝑠𝑡 𝑤𝑕𝑜𝑙𝑒 𝑛𝑢𝑚𝑏𝑒𝑟
Conclusion
Highly plastic soils of a higher P.I tend to contain high silt and clay contents
Those with a lower P.I are medium plastic soils with low clay and silt contents
Soils with a P.I of zero tend to have no silt or clay contents, and are purely coarse soils
3.2.7.3 Linear shrinkage determination test
Objective
This is to obtain a linear shrinkage value to determine the amount of shrinkage/ deformation/
settlement likely to be experienced by a clayey material.
The shrinkage limit refers to the moisture content where further loss of moisture won’t result in
any more volume reduction
The value obtained is also relevant to the converse condition of expansion due to wetting
Principle
The shrinkage limit test works under the principle that water retaining soil type undergoes
significant decrease in size when the water contained within dries up. The level of shrinkage can
be measured relative to a standard half cylindrical shrinkage mould 140mm long with 40mm
diameter
References
BS 1377: Part 2: 1990
Required equipment
 A glass plate
 Palette knives
 Oven that can maintain temperature 105-110ºC
 Clean water
 Linear shrinkage brass mould 140mm long, 40mm diameter
 Grease/ oil/ petroleum jelly
 Steel rule with accuracy 0.5mm
Sample preparation
This test was performed as a continuance of the liquid limit, and plastic limit tests, and the
material for the test was therefore prepared as part of the liquid limit test
Test procedure
The mould was thoroughly cleaned and a thin layer of grease was applied to its inner surfaces to
prevent soil from adhering to the mould

A sample of the soil paste was then placed in the mould such that it slightly exceeds the sides of
the mould
The mould was then tapped gently against a firm surface to eliminate any air pockets in the
mixture
The soil was then levelled along the mould top using a palette knife and all the soil adhering to
the rim of the mould wiped off using a damp cloth
Figure 3.26 shows an example of some shrinkage moulds ready for oven drying.
Figure 3.26: Prepared samples for shrinkage test
The mould was then placed in open air for the paste to dry slowly for 1 day until the soil had
shrunk away from the walls of the mould
The mould was then oven dried for 24 hours at 105ºC
The mould, with the oven dried sample was then taken out of the oven, cooled and the mean
length of the soil bar by pressing against one end of the mould (Refer to figure 3.27).
Figure 3.27: Linear shrinkage samples out of the oven
The distance between the opposite side of the mould and the soil bar was then measured and
recorded

Analysis of results
The linear shrinkage of the soil was calculated as a percentage of the original specimen from the
equation
𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝐿𝑖𝑛𝑒𝑎𝑟 𝑆𝑕𝑟𝑖𝑛𝑘𝑎𝑔𝑒 = 1 −
𝐿 𝐷
𝐿1
× 100 {𝑇𝑜 𝑡𝑕𝑒 𝑛𝑒𝑎𝑟𝑒𝑠𝑡 𝑤𝑕𝑜𝑙𝑒 𝑝𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒}
Where LD is the length of the oven dried specimen (in mm)
L1 is the original length of the specimen (140mm)
3.3 Tests on aggregates
3.3.1 Sieve analysis test
Objective
The main objective was to determine the particle size distribution of the aggregates to be used in
the reconstruction and modification of the pavement base layer, determined by sieving
Main principle
The aggregates to be used were observed to contain other finer particles likely to cause
agglomeration, thus the samples were washed and dried before sieving
References
BS 812: Part 103.1: 1985
Required equipment
 Test sieves aperture sizes: 75mm, 63mm, 50mm, 37.5mm, 28mm, 20mm, 14mm, 10mm,
6.3mm, 5mm, 2.36mm, 1.18mm, 600µm, 425µm, 300µm, 150µm, 75µm
 Lid and receiver
 Balance 30kgs, accuracy 1g
 Riffle boxes
 Drying oven capable of maintaining 105ºC
 Metal trays
 Sieve brushes
Aggregate sampling
Aggregate samples were obtained from Kakiri stone quarry (Refer to figure 3.28), crushed from
huge rocks/ boulders to respective smaller sizes

Figure 3.28: Kakiri stone quarry, aggregate sampling
We obtained our samples in sampling bags, ensuring uniform and proper sampling by shoveling
at several different spots on the stone pile all over the surface (Refer to figure 3.29).
Figure 3.29: Sampling aggregates in bags
Sample preparation
The sample of aggregates obtained from Kakiri stone quarry was air dried
The sample was then quartered in rifle boxes (Refer to figure 3.30) to ensure uniform particle
size distribution, placed in the oven to dry for 12 hours at 105ºC and then allowed to cool in
preparation for dry sieving

Figure 3.30: Sample rifling
Test procedure
The oven dried sample was then weighed (M1) and washed over a 75µm sieve, with a fitted
guard 2.36mm sieve.
Washing was done carefully not to lose any material retained on the test sieve until the water
passing the 75µm sieve was clear
The residues retained were then transferred from the sieve to a metal tray, and the excess free
water removed by careful decantation through the 75µm sieve.
The obtained residues were placed in the oven to dry at 105ºC for 24 hours
The oven dried material was then allowed to cool, and weighed (M2)
The mass of the fine material passing the 75µm sieve could be calculated from;
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙 𝑝𝑎𝑠𝑠𝑖𝑛𝑔 75𝜇𝑚 𝑠𝑖𝑒𝑣𝑒 = 𝑀1 − 𝑀2
The sieves were then assembled in descending aperture size order going to the bottom, and the
oven dried sample was placed on the top sieve and covered with a lid
The sieve set up was then agitated vigorously by hand for a sufficient time to separate the sample
into the different size fractions
Refer to figure 3.31 below for an example of sieve sample agitation.

Figure 3.31: Aggregate sieving
Separation was completed by briefly hand shaking each sieve individually
A tray was used as an intermediate by shaking some sieves over it until no more material passes,
in case the sieves were blinded by overloading to minimize errors. An example of this is shown
in figure 3.32 below.
Figure 3.32: Hand sieving
The material retained on each sieve was then weighed and recorded
The sieve brushes were used to clean out all the material retained on the sieve mesh
Analysis of results
The mass retained on ach sieve was represented as a percentage of the original dry mass (M1).

For the mass passing the finest 75µm sieve, the mass was added to that passing during washing
(M1-M2)
The results obtained were used to construct a gradation curve from which the gradation
properties of the aggregates were determined
The graph was plotted on a semi-logarithmic scale
Table 3.3: Sieve analysis Kakiri stone quarry sample
LOCATION: KAKIRISTONEQUARRY
MATERIAL:CRR(CRUSHEDRUNROCK)
SIEVE
SIZES
(mm)
MASS
RETAINED
(g)
PERCENTAGE
MASS
RETAINED %
CUMULATIVE
PERCENTAGE
MASS
RETAINED %
CUMULATIVE
PRECENTAGE
MASS PASSING
%
20 0 0.00 0.00 100.00
14 0 0.00 0.00 100.00
10 0 0.00 0.00 100.00
5 80 12.01 12.01 87.99
2.36 66 9.91 21.92 78.08
1.18 62 9.31 31.23 68.77
0.6 44 6.61 37.84 62.16
0.425 28 4.20 42.04 57.96
0.3 52 7.81 49.85 50.15
0.212 144 21.62 71.47 28.53
0.15 108 16.22 87.69 12.31
0.075 82 12.31 100.00 0.00
Total 666 100.00

Graph 3.4: Sieve analysis curves
Conclusion
The upper limit symbolizes finer aggregates while the lower limit symbolizes the coarser
aggregates
From the nature of the gradation curve obtained, as compared to the limits dictated by the B.S,
our aggregates obtained from a pile at the Kakiri stone quarry were observed to be well graded
3.3.2 Flakiness index test
Objective
The flakiness test is used to classify aggregates to determine whether they fit the specific
requirements for pavement design
For the base course, the presence of flaky aggregates is considered undesirable as they may cause
inherent weaknesses with possibility of breaking down under heavy loads
Aggregates are considered flaky when they have a thickness of less than 60% of their mean sieve
size
The objective of this test was to determine the flakiness index of the coarse aggregates

Principle
The flakiness index of an aggregate sample is found by separating the flaky particles and
expressing their mass as a percentage of the mass of the sample.
This test is only applicable to material passing a 63mm sieve and retained on a 6.3mm sieve
References
BS 812: Section 105.1: 1989
Required equipment
 Rifle boxes
 Drying oven
 Test sieves (63mm, 50mm, 37.5mm, 28mm, 20mm, 14mm, 10mm, 6.3mm)
 Metal trays
 Metal thickness gauges (Refer to figure 3.33 below)
Figure 3.33: Flakiness index gauge
Sample preparation
The flakiness index test was a continuation of the sieve analysis test, and the material used was
obtained from the material retained on the test sieves in the gradation test
In cases when the flakiness index test was carried out separately, sieve analysis was first carried
out on an oven dried sample, the material retained on the 63mm, and passing the 6.3mm sieve
discarded
Test procedure
The individual size fractions retained on the sieves were stored on trays with their sizes marked
on the trays
The sum of the masses of the fractions on the trays was calculated (M1), and the individual
percentage retained on each of the various sizes was calculated.
Fractions whose mass was less than 5% of the total mass was discarded, and the remaining mass
recorded (M2)

The fractions were then gauged through a thickness gauge, the gauge sizes selected appropriate
to the size-fraction under test, and each particle of that size-fraction was gauged individually by
hand, exemplified in figure 3.34 below.
Figure 3.34: Non flaky aggregates retained on gauge
The particles passing each of the gauges were then combined and weighed (M3)
Analysis of results
The value of the flakiness index was calculated from the expression:
𝐹𝑙𝑎𝑘𝑖𝑛𝑒𝑠𝑠 𝐼𝑛𝑑𝑒𝑥, 𝐹𝐼 =
𝑀3
𝑀2
× 100 (𝑖𝑛 %)
Where M2 is the total mass of fractioned particles considered for the gauge test
M3 is the total mass of particles passing the gauges
Conclusion
Flaky aggregates are undesirable for a base course as they may cause undesirable inherent
weaknesses with possibility of breaking down under heavy loads
It is recommended that aggregates used for road construction should have a flakiness index
below 35%

3.3.3 Specific gravity and water absorption test for coarse aggregates
Introduction
The specific gravity of an aggregate is considered to be a measure of strength or quality of the
material.
Water absorption gives an idea about the strength of an aggregate. Aggregates having more
water absorption are more porous in nature and are generally considered unsuitable unless they
are found to have acceptable results based on strength, impact, and hardness.
This method is used to determine the dry density of aggregates retrieved on a 4.75mm sieve that
can be used for various mix characteristics and in mix design
Objective
To determine the specific gravity and water absorption of aggregates using a perforated basket
Principle
The dry, bulk and apparent density of aggregates retained on a 4.75mm sieve are calculated from
the loss in mass of saturated surface dry aggregates when submerged in water
The water absorption is determined by calculating the mass of water absorbed after a 24 hour
immersion in percentage of the oven dried material
Definitions
1. Density: This is the mass per unit volume of a material at a given temperature
2. Bulk density: This is the mass per unit volume (including permeable and impermeable
voids) of a material at a given temperature
3. Apparent density: This is the mass per unit volume (excluding permeable voids, but
including impermeable voids) of a material at a give temperature
References
ASTM C127-88’’
Required equipment
 Thermometer
 Balance
 Wire basket 4.75mm aperture
 Water bath on specific gravity lever machine
 Oven
 Distilled water
 Dry towels
 Metal trays
 Hook

Sample preparation
The aggregate sample from the quarry was sieved through a 4.75mm sieve and the mass retained
was prepared for the test (Refer to figure 3.35)
Figure 3.35: Sieving soaked aggregates through a 4.75mm sieve
Test procedure
The sample was washed thoroughly to remove dust and any fine particles sticking to the
aggregate surfaces
The sample was then soaked in clean water in a container for 24 hours
Determination of saturated surface dry condition
After soaking the sample, the free water was drained off and the sample transferred to dry
absorbent towels (Refer to figure 3.36).
Figure 3.36: Drying aggregates with towels
The sample was rolled in the cloths until all visible water was absorbed, with the aggregate
surfaces still appearing damp
Here when the saturated surface dry was reached, the weight of the sample was determined, and
sample transferred to a wire basket previously tared in water (Refer to figure 3.37).

Figure 3.37: Weighing aggregates wholly immersed in water
The basket with the sample was weighed in water at 25ºC, taking care that no air was trapped
Determination of dry weight
The water was poured off without losing any material
The material was dried in the oven at 105ºC for 24 hours and record the mass of the oven dried
sample
Analysis of results
The bulk and apparent density were calculated (in g/cm3) and the water absorption (in %) using
the following equation
𝐵𝑢𝑙𝑘 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 =
𝑊1
𝑊2 − 𝑊3
(𝑔/𝑐𝑚3
)
𝐴𝑝𝑝𝑎𝑟𝑒𝑛𝑡 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 =
𝑊1
𝑊1 − 𝑊3
(𝑔/𝑐𝑚3
)
𝑊𝑎𝑡𝑒𝑟 𝑎𝑏𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 =
𝑊2−𝑊1
𝑊1
(%)
Where W1 is the weight of the oven dried sample in air (g)
W2 is the weight of the saturated surface dry sample in air (g)
W3 is the mass of the saturated sample in water at 25ºC (g)
Conclusion
The absorption value of an aggregate indicates its porosity, and ability to absorb water and
binder asphalt material. Thus a high absorption value is undesirable in road construction as it
indicates a non-durable and binder wasting aggregate

3.3.4 Specific gravity and water absorption test for fine aggregates
Objective
The objective of this test is to determine the density of aggregates passing the 4.75mm sieve. The
density of aggregates is used for various calculations of mix characteristics and in mix design.
This method is also used to determine the water absorption of the aggregates
Principle
A material sample in saturated surface dry (SSD) state is weighed into a calibrated pycnometer
with known volume. The pycnometer is then filled with distilled water and entrapped air is
removed.
The pycnometer is then tempered to 25ºC and weighed. This data is used to calculate the bulk,
apparent densities and water absorption of the aggregates
References
ASTM C128-88 and ASTM D854
Required equipment
 Pycnometer
 Thermometer accuracy 0.1ºC
 Electronic dryer
 Balance 8kgs, accuracy 0.1g
 Water bath
 Heating oven able to maintain temperature 105-110ºC
 Distilled water
 Metal mould in form of a frustum, 40mm top diameter, 90mm bottom diameter, 75mm
height with metal thickness 0.8mm
 Metal tamper with flat circular tamping face 25mm diameter
Sample preparation
The material was sieved on a 4.75mm sieve to obtain samples
The sample was soaked in a container with water at 25ºC for 24 hours
Test procedure
Determining the SSD condition
After soaking the sample, the excess water was decanted off without losing any material and the
material was spread onto a metal tray.
The sample was exposed to a moving current hot air, using a dryer. The sample was stirred
frequently to ensure uniform drying (Refer to figure 3.38), until the material approached a free-
flowing condition

Figure 3.38: Drying aggregates with hair dryer
The conical mould was placed on a flat surface with the smaller opening facing upwards. It was
filled loosely to overflowing with the partially dried material.
The surface was tamped lightly 25 times with the tamping rod, each drop starting about 5mm
above the surface and no additional material was added during or after the tamping
The mould was lifted vertically.
If the material retained its shape (Refer to figure 3.39 below), it meant that free water was still
present.
Figure 3.39: Aggregates slump intact, wetter than SSD state
The material was then dried further and the cone test repeated until the material slump collapses
slightly on removal of the mould (Refer to figure 3.40).
This indicated that the SSD condition had been reached.

Figure 3.40: Aggregates slump just failed, SSD condition present
If material had slumped on first trial, there was probable drying beyond SSD state, thus a few ml
of water would be added to the sample, and permitted to stand in a covered container for 30
minutes
The wetting and drying and testing process was continued until the SSD state was reached
Filling of pycnometer and removal of entrapped air
The material was transferred to a pycnometer, and the mass of pycnometer and sample obtained
The pycnometer was then filled with distilled water until about 2/3 full. It was then agitated to
eliminate air bubbles
The pycnometer was then carefully filled with distilled water and plugged
The water level in the pycnometer was levelled with a pipette to the fitting line on the glass top.
The pycnometer was then dried on the outside and weighed with its contents
The material was then transferred to a container, excess water poured off carefully not to lose
any material, and the material dried in an oven at 105ºC for 24 hours
The material was then taken out of the oven, allowed to cool and then weighed
Analysis of results
The bulk density, apparent density and water absorption were calculated from the following
expressions:
𝐵𝑢𝑙𝑘 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝜌𝑏 =
𝐴
𝐷 − (𝐶 − 𝐵)
(𝑔/𝑐𝑚3
)
𝐴𝑝𝑝𝑎𝑟𝑒𝑛𝑡 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝜌 𝑎 =
𝐴
𝐷 − (𝐶 − 𝐴 − 𝐸)
(𝑔/𝑐𝑚3
)
𝑊𝑎𝑡𝑒𝑟 𝑎𝑏𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 =
𝐵 − 𝐸 − 𝐴
𝐴
× 100%
Where A = Mass of oven dry sample (g)
B = Mass of SSD sample + pycnometer (g)

C = Mass of saturated sample + pycnometer filled with water (g)
D = Volume of pycnometer (cm3
)
E = Mass of clean dry pycnometer (g)
3.4 Insitu tests
3.4.1 Field density test by sand replacement method
Introduction
The dry density of compacted soil or pavement material is a common measure of the amount of
the compaction achieved. Knowing the field density and field moisture content, the dry density is
calculated.
It is one of the several methods to determine field density, as well as core cutter method, sand
replacement, rubber balloon, heavy oil method, etc.
The sand replacement procedure was carried out on a trial pavement section along CH 24+000 to
25+000 of 200mm with one round of compaction that had been constructed to determine the
density and compaction rate achieved.
Objective
To determine the field density of compacted base layer by sand replacement method
References
IS: 2720- PART-28
Principle
The basic principle is to measure the insitu volume of a hole from which the material was
excavated from the weight of sand with known density filling the hole. The insitu density of the
material is given by the weight of the excavated material divided by the insitu volume
Required equipment
 Sand pouring cylinder
Large capacity 16.5litres, 200mm diameter, 610mm length
Medium: Capacity 150mm diameter, length 450mm
 Leveling, excavating and scooping tools; Hand tools like scraper, hammer and chisel
 Metal trays, some intact and with holes in middle 150mm diameter
 Sand
 Test sieves; 600mm and 300mm and 75µm aperture
 Air tight bags
 Glass plate

Test procedure
Sand calibration
Sand was obtained from Kikubampanga, a village at CH 30+800, offset 8kms RHS of the road,
from an excavated piece of land rich in sand material and then taken to the laboratory in
sampling bags.
Excavation and sampling can be exemplified in the figure 3.41 below.
Figure 3.41: Excavating and sampling sand for field density test
It was washed on a 75µm sieve to eliminate silt sized particles, then spread out on a clean surface
to sundry for 36 hours (Refer to figure 3.42).

Figure 3.42: Drying washed sand
The sand was then sieved through a setup of 600mm and 300mm sieves, and material retained on
the 300mm sieve was transferred to a metal pan and the rest discarded
A mass of 16kgs of sand was poured into the sand pouring cylinder with a cone of known
capacity placed on a glass plate, and the shutter opened
Sand calibration is exemplified in figure 3.3 below.
Figure 3.43: Determining density of sand with sand pouring cylinder
The shutter was then opened, sand left to pour into the cone of known volume and the remaining
sand in the cylinder was weighed
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑠𝑎𝑛𝑑 𝑖𝑛 𝑐𝑜𝑛𝑒 = 𝑀𝑎𝑠𝑠 𝑝𝑜𝑢𝑟𝑒𝑑 − 𝑀𝑎𝑠𝑠 𝑙𝑒𝑓𝑡 𝑖𝑛 𝑡𝑕𝑒 𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 𝑎𝑓𝑡𝑒𝑟 𝑝𝑜𝑢𝑟𝑖𝑛𝑔
𝐷𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑠𝑎𝑛𝑑 =
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑠𝑎𝑛𝑑 𝑖𝑛 𝑐𝑜𝑛𝑒
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑡𝑕𝑒 𝑐𝑜𝑛𝑒
The procedure was repeated using different sized sand pouring cylinders, and the average density
from the different tests was determined

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