TABLE OF CONTENTS

DECLARATION......................................................................................................i

APPROVAL...........................................................................................................ii

ACKNOWLDGEMENTS.......................................................................................... iii

ABSTRACT..........................................................................................................iv

LIST OF FIGURES............................................................................................... vii

LIST OF TABLES ............................................................................................... viii

LIST OF ACRYONMS/ABBREVIATION ....................................................................ix

CHAPTER ONE ...............................................................................................1

1.1 INTRODUCTION............................................................................................ 1

1.1.1 Background................................................................................................ 1

1.2 Problem Statement........................................................................................ 2

1.3 Objectives of the study .................................................................................. 2

1.3.1 Main objective ............................................................................................ 2

1.3.2 Specific Objectives ...................................................................................... 2

1.4 Scope........................................................................................................... 3

1.5 Justification................................................................................................... 3

CHAPTER TWO ..............................................................................................4

LITERATURE REVIEW....................................................................................4

2.0 Introduction.................................................................................................. 4

2.1 Strength ....................................................................................................... 4

2.2 Moisture content ........................................................................................... 4

2.3 Shrinkage/swelling......................................................................................... 4

2.4 Shrinkage/swelling......................................................................................... 5

2.5 The role of sub-grade .................................................................................... 6

2.6 Soil stabilization ............................................................................................ 8

2.6.1 Types of stabilization .................................................................................. 9

2.7 Previous studies on soil stabilization using other means than cement and lime. .11

vi

CHAPTER THREE .........................................................................................14

METHODOLOGY...........................................................................................14

3.0 Introduction.................................................................................................14

3.1 Materials......................................................................................................14

3.1.1 Soil...........................................................................................................14

3.1.2 Coffee husk ash.........................................................................................14

3.2 Tests that were carried out ...........................................................................15

CHAPTER FOUR ...........................................................................................16

RESULT ANALYSIS AND DISCUSSION.........................................................16

4.0 Introduction.................................................................................................16

4.1 Result analysis .............................................................................................16

4.1.1 Particle size distribution..............................................................................16

4.2.2: Plasticity index .........................................................................................18

4.2.3 Maximum Dry Density ................................................................................18

4:2.4 California Bearing Ratio..............................................................................19

CHAPTER FIVE.............................................................................................20

CONCULSIONS AND RECOMMENDATIONS .................................................20

5.1 CONCLUSIONS .............................................................................................20

5.2 RECOMMENDATIONS....................................................................................20

REFERENCES .....................................................................................................21

APPENDICES .....................................................................................................24

APPENDIX I: PHOTOS TAKEN..............................................................................24

APPENDIX II: LAB TESTS....................................................................................25