ABSTRACT

Sugarcane as an agricultural product is a readily available source of food for its sugar

content. However, Sugarcane Bagasse Ash (SCBA) is the bi- product formed at sugar

industries from the burning of sugarcane after the sugar content has been extracted.

Sugarcane Bagasse Ash (SCBA) is a fibrous waste product containing mainly aluminum and

silica, calcium ions to produce calcium aluminate hydrate (CAH) and calcium silicate

hydrate (CSH) shown in the pozzolanic reaction below.

Ca2+ + 2(OH)- + Al2O3 (clay alumina > CAH

Ca2+ + 2(OH)- + SiO3 (clay silica)) > CSH

Over the years, sugarcane has posed adverse hazardous environmental impacts due to the

poor disposal methods. From research, sugarcane bagasse ash (SCBA) has been found to

improve the stability and overall suitability of any type of soil for engineering (construction)

purposes amongst other uses.

During my project, 1%, 2%, and 3% sugarcane bagasse ash (SCBA) was mixed with

equivalent proportions by weight of dry laterite soil.

Results:

a. The liquid limit (LL) increased from 35% to 46% and gradually decreased to 41%

with increase in sugarcane bagasse ash (SCBA) content.

b. The plastic limit (PL) increased from 22.5% to 28.3% and gradually increased to

32.9%.

c. The plastic index (PI) increased from 12.5% to 17.7% and gradually decreased to

8.1 with increase in sugarcane bagasse ash (SCBA) content.

d. The shear strength increased gradually I.e. C= 17KN/m2 @ 20o showing a relatively

increased cohesion as angle reduced.

e. Moisture content remained relatively same between (17.5 - 19.2) % as dry density

reduced from 1.738g/cm3 to 1.702g/cm3

The California Bearing Ratio (CBR) values increased gradually from 20.11% to 26.06%.

Addition of increased SCBA content is however necessary to attain minimum CBR standard

of 30%. (BS 1990).

KEYWORDS: Sugarcane, Sugarcane Bagasse, Sugarcane Bagasse Ash (SCBA),

Agricultural Waste, Stabilization, Treatment, Atterberg Limits ((Plastic (PL) & Liquid (LL)

Limits) & Plastic Index (PI)), Shear Stress, California Bearing Ratio (CBR), Compaction,

Fine-Grained Soil, Particle Size Distribution.

vi

TABLE OF CONTENTS

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

CERTIFICATION ..........................................................................................................................ii

DEDICATION...............................................................................................................................iii

ACKNOWLEDGEMENT ............................................................................................................iv

ABSTRACT....................................................................................................................................v

LIST OF FIGURES.......................................................................................................................ix

LIST OF TABLES.........................................................................................................................xi

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

INTRODUCTION ..........................................................................................................................1

1.1 BACKGROUND OF STUDY....................................................................................1

1.1.1 Soil Stabilization..........................................................................................................1

1.1.2 Laterite Soil..................................................................................................................1

1.1.3 Sugarcane, Bagasse & Sugarcane Bagasse Ash (SCBA)..........................................1

1.2 RESEARCH PROBLEMS..........................................................................................2

1.3 JUSTIFICATION FOR RESEARCH ........................................................................2

1.4 AIM AND OBJECTIVES OF RESEARCH..............................................................2

1.4.1 Aim of Research ..........................................................................................................2

1.4.2 Objectives of Research................................................................................................2

1.5 PROBLEM STATEMENT .........................................................................................3

1.6 RESEARCH METHODOLOGY ...............................................................................3

1.7 SCOPE OF STUDY ....................................................................................................3

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

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

2.1 LOCATION OF STUDY............................................................................................4

2.1.1 Material Sourcing ........................................................................................................4

2.2 SOIL .............................................................................................................................5

2.2.1 Soil Formation .............................................................................................................5

2.2.2 Soil Weathering ...........................................................................................................5

2.2.3 Factors affecting Soil Weathering ..............................................................................6

2.2.4 Soil Features and Composition ...................................................................................6

2.3 SUGARCANE BAGASSE ASH (SCBA).................................................................6

2.3.1 Introduction..................................................................................................................6

2.3.2 Composition of Sugarcane Bagasse Ash (SCBA).....................................................7

vii

2.3.3 Formation of Sugarcane Bagasse Ash (SCBA) .........................................................7

2.3.4 Case Studies (Wubshet, 2013)....................................................................................8

2.4 SOIL STABILIZATION...........................................................................................10

2.4.1 Methods of Soil Stabilization ...................................................................................10

2.4.2 Effects of a Well Compacted Soil ............................................................................11

2.4.3 Processes in Compaction Efforts..............................................................................11

2.4.4 SCBA Stabilization of a Fine-Grained Lateritic Soil..............................................11

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

MATERIALS & ANALYSIS TECHNIQUES.......................................................................14

3.1 INTRODUCTION.....................................................................................................14

3.2 MATERIALS.............................................................................................................14

3.3 ANALYSIS TECHNIQUES.....................................................................................14

3.3.1 Sample Preparation....................................................................................................15

3.4 PRELIMINARY SOIL LABORATORY TESTS...................................................15

3.4.1 Atterberg Limits Experiment ....................................................................................15

3.4.1.1 The Liquid Limit Experiment (LL) ..........................................................................16

3.4.1.2 The Plastic Limit Test (PL).......................................................................................16

3.4.2 Compaction Experiment on Soil...............................................................................18

3.4.3 Factors Affecting Soil Compaction ..........................................................................19

3.4.4 Factors Affecting Degree of Soil Compaction ........................................................19

3.4.2.1 Standard Proctor Compaction Test...........................................................................20

3.4.3 California Bearing Ratio (CBR) Experiment...........................................................22

A. Apparatus...................................................................................................................23

B. Test Procedure ...........................................................................................................23

3.4.4 Direct Shear Strength Experiment............................................................................24

A. Apparatus...................................................................................................................25

B. Procedure....................................................................................................................26

CHAPTER FOUR ........................................................................................................................27

RESULTS AND DISCUSSION..............................................................................................27

4.1 ATTERBERG LIMITS (LL, PL & PI) ....................................................................27

4.1.1 Liquid Limit (LL)......................................................................................................31

4.1.2 Plastic Limit (PL) ......................................................................................................31

4.1.3 Plastic Index (PI) .......................................................................................................32

4.2 DIRECT SHEAR STRESS.......................................................................................33

4.3 COMPACTION TEST..............................................................................................37

viii

4.4 CALIFORNIA BEARING RATIO (CBR)..............................................................43

CHAPTER FIVE ..........................................................................................................................48

CONCLUSION AND RECOMMENDATION......................................................................48

5.1 CONCLUSION..........................................................................................................48

5.2 RECOMMENDATION ............................................................................................48

REFERENCES .............................................................................................................................49