vii
TABLE OF CONTENTS
CHAPTER
TITLE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xiv
LIST OF FIGURES
xix
LIST OF ABBREVIATIONS
LIST OF SYMBOLS
LIST OF APPENDICES
1
2
PAGE
xxvi
xxviii
xxxi
INTRODUCTION
1
1.1
Background of Research
1
1.2
Problem Statement
5
1.3
Objectives of Research
6
1.4
Scope of Research
7
1.5
Significance of Research
7
1.6
Thesis Organisation
8
LITERATURE REVIEW
10
2.1
Introduction
10
2.2
Coal Fired Power Plant in Malaysia
13
2.3
Coal Combustion Products
16
2.3.1
Introduction
16
2.3.2
Fly Ash
20
viii
2.3.3
2.4
2.5
2.3.2.1 Class C fly ash
21
2.3.2.2 Class F fly ash
21
Bottom Ash
22
Physical Properties of Coal Ash
23
2.4.1 Appearance and Shape
23
2.4.2 Specific Gravity
26
2.4.3 Particle Size Distribution
28
Mechanical Properties of Coal Ash
32
2.5.1
Compaction Behaviour
32
2.5.2
Permeability (Hydraulic Conductivity)
36
2.5.3
Strength
39
2.5.3.1 Shear Strength Parameter
39
2.5.3.2 California Bearing Ratio
44
2.5.4 Compressibility
2.6
2.7
2.8
Morphological, Mineralogical, Pozzolanic
Activity and leachate Properties
48
2.6.1 Microscopic Examination of Particles
48
2.6.2 Mineral Composition
51
2.6.3 Chemical Analysis
53
2.6.4 Pozzolanic Activity
55
2.6.5 Heavy Metal and Corrosivity of Coal Ash
56
Properties of Coal Ash Mixtures
60
2.7.1 Particle Size Distribution
61
2.7.2 Compaction Characteristics
63
2.7.3 Permeability
65
2.7.4 Strength and Compressibility
66
Utilisation of Coal Ash in Geotechnical
Engineering Work
2.9
2.10
45
67
Environmental Aspects of Coal Ash Usage
in Geotechnical Engineering Work
70
Soft Clay Problems
71
2.10.1 Introduction
71
2.10.2 Bearing Capacity
72
2.10.3 Consolidation Settlement
74
ix
2.11
2.10.4 Properties of Soft Clay
74
Physical Modelling of Embankment
78
2.11.1 Full-Scale Tests of Embankment on Soft Soil
78
2.11.2 Full-Scale Test of Embankment using Fly Ash
as Backfill Materials
2.11.3 Laboratory Physical Model Test
2.12
3
80
82
2.11.3.1 Introduction
82
2.11.3.2 Development of Dimension Model
82
Summary
85
RESEARCH METHODOLOGY
86
3.1
Introduction
86
3.2
Research Activities
87
3.2.1
87
Research Design
3.2.2 Literature Search and Information Collection
89
3.2.3 Sample Collection and Preparation
89
3.2.3.1 Sample Collection
89
3.2.3.2 Preparation of Fly Ash and Bottom Ash
Samples
3.3
91
3.2.3.3 Preparation of FA-BA Mixtures
91
3.2.3.4 Curing of the Samples
93
3.2.4 Equipment Preparation and Calibration
93
Sample Characterisation and Properties Establishment
95
3.3.1 Laboratory Testing Programme
95
3.3.2 Physical Tests
98
3.3.2.1 Specific Gravity
98
3.3.2.2 Sieve Test
99
3.3.2.3 Hydrometer Test
100
3.3.2.4 Atterberg Limit Test
102
3.3.3 Material Characterisation and Geochemistry Tests 103
3.3.3.1 Morphology Characteristics
103
3.3.3.2 Mineralogy Characteristics
104
3.3.3.3 Element Characteristics
105
x
3.3.3.4 Thermal Analysis
106
3.3.3.5 Heavy Metal Study
107
3.3.3.6 pH Test
109
3.3.4 Mechanical Tests
109
3.3.4.1 Direct Shear Test
109
3.3.4.2 California Bearing Ratio
111
3.3.4.3 Permeability Test
112
3.3.4.4 Consolidation Test
115
3.3.4.5 Unconfined Compression Test
116
3.5
Analysis of Data
3.6
Determination of Settlement of FA-BA Mixtures as
118
Soft Clay Replacement
118
3.6.1 Laboratory Physical Model
118
3.6.1.1 Introduction
118
3.6.1.2 Model Size and Design
119
3.6.2 Size of Test Box Model
3.6.2.1 Considering Soft Clay, ɸ = 34.030
121
122
3.6.2.2 Considering the Strongest FA-BA
Mixtures, ɸ = 36.850
123
3.6.3 Fabrication of Model Test Box
124
3.6.4 Loading Frame for Soft Soil Preparation
125
3.6.5
Load Testing Assembly for Settlement
127
3.6.6 Testing Programme for Model Tests
129
3.6.7 Preparation of Sample
130
3.6.7.1 Soft Clay Preparation
130
3.6.7.2 Preparation of Full FA-BA Mixture Layer 132
3.6.7.3 Preparation of Partially Replaced Soft Clay
with FA-BA Mixtures Layer
134
3.6.8 Settlement Test & Monitoring
134
3.6.9 Anaysis of Settlement Test Results
135
xi
4
PHYSICAL, MORPHOLOGICAL, MINERALOGY
AND MECHANICAL CHARACTERISTICS
OF FA-BA MIXTURES
136
4.1
Introduction
136
4.2
Physical Characteristics
137
4.2.1 Specific Gravity
137
4.2.1.1 FA-BA Mixtures
137
4.2.1.2 Kaolin
139
4.2.2 Particle Size Distribution
139
4.3
Morphology Characteristics
141
4.4
Mineralogy Characteristics
153
4.5
Mechanical Characteristics
155
4.5.1 Compaction
155
4.5.2 Permeability
159
4.5.3 Strength Behaviour
163
4.5.3.1 Unconfined Compression Strength
163
4.5.3.2 Direct Shear of FA-BA Mixtures
168
4.5.3.3 Direct Shear of Kaolin
175
4.5.3.4 Undrained Strength of Kaolin
176
4.5.3.5 California Bearing Ratio
178
4.5.4 Compressibility of FA-BA Mixtures
5
181
CHEMICAL, POZZOLANIC ACTIVITY, CORROSIVITY
AND HEAVY METAL CHARACTERISTICS
OF FA-BA MIXTURES
189
5.1
Introduction
189
5.2
Chemical Characteristic
189
5.3
Thermal Gravimetri Analysis
196
5.4
pH Characteristics
199
5.5
Heavy Metal Content
201
xii
6
SETTLEMENT OF SOFT CLAY REPLACED BY
FULLY AND PARTIALLY FA-BA MIXTURES
204
6.1
Introduction
204
6.2
Properties of Compacted Soft Clay and FA-BA Mixtures 205
6.3
Settlement Results of Model Tests
206
6.3.1 Full Replacement
207
6.3.1.1 Time-Settlement Behaviour
207
6.3.1.2 Effect of FA Content
210
6.3.2 Partial Replacement
7
214
6.3.2.1 Time-Settlement Behaviour
214
6.3.2.2 Effect of Replacement Height Ratio
217
DESIGN CHARTS FOR APPLICATION OF COAL ASH
MIXTURES AS ALTERNATIVE MATERIALS IN
GEOTECHNICAL ENGINEERING WORKS
221
7.1
Introduction
221
7.2
Recommendations for the Selection of Design Parameters 222
7.2.1
7.3
Environmental Aspects
223
7.2.2 Design Aspects
224
7.2.3 Construction Aspects
225
Proposed Design Chart for FA-BA Mixtures as
Replacement Materials
7.3.1
225
Unconfined Compressive Strength versus Fly Ash
Content Charts
226
7.3.2 Settlement Chart for FA-BA Mixtures in
Full Soil Replacement
232
7.3.3 Settlement Chart for Partially Replaced Soft Clay
8
by FA-BA Mixtures
234
CONCLUSION AND RECOMMENDATIONS
236
8.1
Introduction
236
8.2
Conclusion
237
8.3
Contribution of Research
239
xiii
8.4
8.3.1 Ground Improvement
239
8.3.2 Sustainability
239
8.3.3 Economy
240
8.3.4 Originality
240
Recommendations for Future Research
241
REFERENCES
Appendices A-N
242
248-350
xiv
LIST OF TABLES
TABLE NO.
2.1
TITLE
PAGE
Total energy supply and coal consumption in some
countries in 2003 (Fujitomi and Matsui, 2005)
11
2.2
Generation mix by fuel kind (Energy Commission Malaysia, 2005) 12
2.3
List of Coal-Fired Power Stations in Malaysia up to year 2010
(Jaffar, 2009)
2.4
14
Coal demand estimations for year 2010 to 2030 (based on Year
2005) (Ghazali, 2007)
15
2.5
Worldwide FA production (Geertsema, 2007)
19
2.6
Chemical content of class C pulverised fly ash
(ASTM C 618, 2004)
21
2.7
Chemical content of PFA class F (ASTM C 618, 2004)
22
2.8
Specific gravity and chemical composition of FA and BA
2.9
from the Wabash River Plant, USA (Kim et al., 2005a)
27
Typical specific gravity for different origins of Fly Ash
28
(Muhardi et al. 2010)
2.10
Permeability of Indian FA (Pandian, 2004)
36
2.11
Permeability of Indiana FA (Kim, 2003)
37
2.12
Permeability of the Wabash River Plant ash mixtures
(Kim et al., 2005a)
37
2.13
Hydraulic conductivity of typical soils (Terzaghi et al. 1996)
38
2.14
Results of direct shear tests on Indiana Bottom Ashes
(Huang, 1990)
2.15
Results of peak friction angle of Indiana FA from direct shear test
(Kim, 2003)
2.16
40
41
Results of cohesion of Indiana FA from direct shear test
(Kim, 2003)
41
xv
2.17
Results of strength parameters under different test
conditions of FA from India (Pandian, 2004)
2.18
Peak shear strength parameters taken from direct shear tests
for different age specimens (Tri Utomo, 1996)
2.19
42
Residual strength parameters taken from direct shear test on
FA at different age specimens (Tri Utomo, 1996)
2.20
42
43
Peak and residual strength parameters taken from consolidated
drained triaxial on FA at different age specimens
(Tri Utomo, 1996)
2.21
43
CBR values according to Road Note 29
(TRRL Laboratory Report 1132)
44
2.22
Results of compression index for Indian FA (Pandian, 2004)
46
2.23
Results of coefficient of volume change, mv (cm2/kg)
for Indian FA (Pandian, 2004)
2.24
Results of coefficient of consolidation, Cv (10-3/kg)
for Indian FA (Pandian, 2004)
2.25
47
Results of compression index at different placement
conditions for Indian FA (Pandian, 2004)
2.26
47
48
Mineralogy of the coal fly ash from the AE
power plant (Suphi, 2005)
52
2.27
Mineral content in Candiota coal (Marcal et al., 2004)
52
2.28
Typical range of analysis from UK fly ash (Reed, 2005)
54
2.29
Chemical analysis of coal ash (Huang, 1990)
55
2.30
Indiana Administrative Code restricted wasted site type
criteria Indiana Administrative Code, 329 IAC 2-9-3 (IAC 1993)
58
2.31
Compaction properties of ash mixtures (Kim, 2003)
64
2.32
Permeability of Wabash River Plant ash mixtures
(Kim et al., 2005a)
2.33
Uses of Coal Combustion Products in Highway Applications
(GAI and USIFCAU, 1993)
2.34
67
Utilization of coal ash and quantities used in each area during
2001 in the USA in thousand tons (Kim, 2003)
2.35
65
68
Utilization of Fly ash and quantities used in Europe for each area
in 1999 (Meij and Berg, 2001)
69
xvi
2.36
Utilization of Fly ash and quantities used in each area in 1997
in UK (Sear, 2001)
2.37
Comparison of index properties of clay in different places
(Jamal et al., 1997)
2.38
75
Classification properties of clay soil from
West Coast of Peninsular Malaysia
2.39
69
76
Typical value of compression index of different type
of soil (GEO5 user‟s guide, 2010)
77
2.40
Properties of kaolin used by previous researchers
78
2.41
Comparison of Delaware and Pennsylvania full scale FA
embankment (after Yoon et al., 2009, Golden and
DiGioia, 2003 and Ki, 2003)
81
3.1
List of major equipments
94
3.2
Laboratory tests and standard/method used
97
3.3
Laboratory testing programme for FA-BA mixtures
98
3.4
Laboratory model settlement programme
130
4.1
The value of specific gravity of coal ash mixtures
137
4.2
The comparison of specific gravity and iron oxide
of FA-BA mixtures
4.3
139
Basic grain size indices and the classification of
FA-BA mixtures from Unified Soil Classification
System (USCS)
141
4.4
Summary of mineral composition of coal ash mixtures
155
4.5
Standard proctor compaction test results for coal ash mixtures
156
4.6
Coefficient of permeability, k of various mixtures
at different curing periods
159
4.7
Unconfined compression strength of FA-BA mixtures at
various curing period
4.8
Normal stress and peak stress obtained from direct shear
tests on FA-BA mixtures at various curing periods
4.9
170
Shear strength parameters from direct shear test for
FA-BA mixtures at various curing periods
4.10
164
Shear strength of FA-BA mixtures at normal stress
171
xvii
of 50 kN/m2 at various curing periods
174
4.11
Direct shear test result of soft kaolin
176
4.12
Undrained shear strength results from vane
shear tests on reconstituted soft kaolin
177
4.13
Variation of CBR values with FA content and curing periods
178
4.14
Shear strength of FA-BA mixtures at various
normal stress (28 day curing period)
4.15
Summary result on compressibility characteristics
of FA-BA mixtures
5.1
191
Chemical content of Tanjung Bin fly ash and bottom ash
at pure condition (14 day)
5.6
191
Chemical content of Tanjung Bin fly ash and bottom ash
at pure condition (0 day)
5.5
190
Chemical content of ash at pure condition (28 days)
curing time
5.4
190
Chemical content of ash at pure condition (14 days)
curing time
5.3
183
Chemical content of ash at pure condition (0 days)
curing time
5.2
180
192
Chemical content of Tanjung Bin fly ash and bottom ash
at pure condition (28 day)
192
5.7
Mass loss of Ca(OH)2 (at 5000C to 600)0C) for ash mixtures
197
5.8
pH value of FA-BA mixtures
199
5.9
AAS test results at 0 day curing period
202
5.10
AAS test result at 14 day curing period
202
5.11
AAS test result at 28 day curing period
202
6.1
Properties of reconstituted soft clay (kaolin)
205
6.2
Properties of compacted FA-BA mixtures
206
6.3
Settlement of soft clay layer and the layer of FA-BA
mixtures at 3, 7, 14, and 28 days after loading
6.4
Settlement at day 28 of soft clay layer and
the layer of FA-BA mixtures
6.5
208
209
Values of constant A, B and C from
Equation 6.1, obtained from Fig. 6.2
211
xviii
6.6
Regression equations of A, B and C with
coefficient of determination, R2
6.7
212
Settlement of partially replaced soft clay with 50%FA–50%BA
mixtures at 3,7,14 and 28 day of loading
216
6.8
Settlement at day 28 of soft clay layer and the layer of FA-BA217
6.9
Values of constants c and m from Equation 6.3
6.10
Regression equation of c and m with coefficient
218
of determination, R2
219
7.1
Values of constant c and m from Equations 7.1 and 7.2
227
7.2
Regression equations of c and m with coefficient
of determination, R2
229
xix
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
Location of coal fired power plants in
Peninsular Malaysia (Mahmud, 2008)
2.1
2
Energy input in power stations for (a) Year 1998 and (b) Year
2005 (Ghazali, 2007)
12
2.2
Coal-fired power stations in Malaysia (Jaffar, 2009)
14
2.3
Tanjung Bin Coal-Fired Power Plant, Johor
(Muhardi et al., 2010)
2.4
16
Schematic diagram of a coal fired power station
(Meij and Berg, 2001)
17
2.5
Schematic diagram of coal ash generation (FHWA, 2002)
18
2.6
Production of coal ash in the USA (Kim, 2003)
19
2.7
Fly ash and bottom ash collected from coal-fired power plant
(Muhardi, 2010)
2.8
20
Fly Ash particles at 2000x magnification (American Coal Ash
Association, 2003)
23
2.9
Particle shape of the bottom ash (Chen et al., 2008)
24
2.10
Coal ashes as by-products of coal burning
(a) Fly ash (b) Bottom ash (Kim et al., 2005a)
24
2.11
Typical gradation ranges of coal ash (Kim, 2003)
29
2.12
Grain size distributions of bottom ash and fly ash (Lee, 2008)
30
2.13
Grain distributions for each FA, BA and coal ash
mixtures (Kim et al., 2005b)
31
2.14
Compaction curves of ash mixtures (Kim et al., 2005b)
32
2.15
Typical compaction curves for Western Pennsylvania bituminous
FA (Kim, 2003)
2.16
Typical compaction curves for Western United States lignite and
33
xx
sub bituminous FA (Kim, 2003)
2.17
Dry density and water content relation for Indian fly ash and soils
(Pandian, 2004)
2.18
45
SEM photographs of fly ash and bottom ash
(Ctvrtnickova et al., 2010)
2.21
38
CBR value with different proportions of fly ash with different
kinds of soil (Sahu, 2001)
2.20
35
Hydraulic conductivity versus FA content from Wabash
River Plant (Kim et. al., 2005b)
2.19
34
49
Scanning electron microscope (SEM) photomicrographs of
bottom ash (a) pure specimen and (b) 28 days compacted
specimen (Lee, 2008)
2.22
Particle size distributions of the Wabash River Plant fly ash,
bottom ash, and fly-bottom ash mixtures (Yoon, 2005)
2.23
63
Compaction curves of fly ash and bottom ash mixtures from
the A.B.Brown Plant (Kim, 2005)
2.26
62
Compaction curves of fly ash and bottom ash mixtures from
the Wabash River Plant (Kim, 2003)
2.25
62
Particle size distributions of the A.B.Brown Plant fly ash,
bottom ash, and fly-bottom ash mixtures (Yoon, 2005)
2.24
50
64
Hydraulic conductivity againt FA content of FA-BA
mixtures of coal ash from from Wabash River Plant
(Kim et al., 2005b)
2.27
Failure modes of shallow foundation (redrawn
after Vesic (1973) by Das, 2004)
2.28
66
72
Failure mechanism from general shear failure of
shallow foundation (Sutjiono and Najoan, 2005)
83
3.1
Flowchart of research activities
88
3.2
Tanjung Bin coal-fired power station Pontian, Johor
90
3.3
Supplied kaolin in bags, stored at a dry place in the laboratory
90
3.4
Apparatus for standard proctor compaction test
92
3.5
Curing of FA-BA mixtures sample
93
3.6
Portable data logger type UCAM-70A
95
3.7
Pycnometer test apparatus
99
xxi
3.8
Sieve tests apparatus
100
3.9
Hydrometer test apparatus
101
3.10
ZEISS SUPRA 35-VP scanning electron microscope
103
3.11
X-ray diffractometer of type Siemens Diffraktometer D5000
105
3.12
X-ray fluorescence of type Bruker AXS Model S4 Pioneer
chemical element of sample
106
3.13
TGA/SDTA 851 Model (METTLER TOLEDO)
107
3.14
TRACE AI1300-AAS model
108
3.15
pH meter test equipment
109
3.16
Direct shear test equipment
111
3.17
California bearing ratio (CBR) test equipment
112
3.18
Falling head permeability equipment
113
3.19
Schematic diagram of constant head permeability test
115
3.20
Oedometer consolidation test equipment
116
3.21
Unconfined compression test apparatus
117
3.22
Schematic diagram of laboratory settlement model test
119
3.23
Sectional view of the test models series for (a) Double layer
(b) Single layer (FA-BA mixtures) (c) Single layer (soft clay)
121
3.24
Details of loading plate and model test box
125
3.25
Schematic diagram of loading frame for preparation of
homogeneous soft kaolin clay soil
126
3.26
Schematic diagram of loading frame for consolidation tests
128
3.27
Details of load connection frame
128
3.28
Dimension of loading plate model (strip footing)
129
3.29
Location of vane shear tests on the reconstituted soft clay soils
131
3.30
Preparation of homogeneous soft clay by consolidation process
132
3.31
Mixing of FA-BA mixtures in concrete mixer machine
133
3.32
Completed compacted FA-BA mixture in test box model
133
3.33
Settlement test on prepared soft clay model
135
4.1
Specific gravity at different FA composition
138
4.2
Grain size distribution of coal ash mixtures
140
4.3
SEM micrograph of coal ash mixtures particles (0 day)
(Magnification ×1000), (a) 0%FA; (b) 30%FA;
(c) 50%FA; (d) 70%FA; (e) 90%FA; (f) 100%FA
144
xxii
4.4
SEM micrograph of coal ash mixtures particles (14 days)
(Magnification ×1000), (a) 0%FA; (b) 30%FA; (c) 50%FA;
(d) 70%FA; (e) 90%FA; (f) 100%FA
4.5
145
SEM micrograph of coal ash mixtures particles (28 days)
(Magnification ×1000), (a) 0%FA; (b) 30%FA; (c) 50%FA;
(d) 70%FA; (e) 90%FA; (f) 100%FA
4.6
SEM micrograph of coal ash mixtures particles (0%FA)
(Magnification ×1000), (a) 0 day; (b) 14 day; (c) 28 day
4.7
151
SEM micrograph of coal ash mixtures particles (100%FA)
(Magnification ×1000), (a) 0 day; (b) 14 day; (c) 28 day
4.12
150
SEM micrograph of coal ash mixtures particles (90%FA)
(Magnification ×1000), (a) 0 day; (b) 14 day; (c) 28 day
4.11
149
SEM micrograph of coal ash mixtures particles (70%FA)
(Magnification ×1000), (a) 0 day; (b) 14 day; (c) 28 day
4.10
148
SEM micrograph of coal ash mixtures particles (50%FA)
(Magnification ×1000), (a) 0 day; (b) 14 day; (c) 28 day
4.9
147
SEM micrograph of coal ash mixtures particles (30%FA)
(Magnification ×1000), (a) 0 day; (b) 14 day; (c) 28 day
4.8
146
152
Crystalline compounds at 50% FA-BA mixtures from XRD
Difractograms
154
4.13
Dry unit weight at various coal ash mixtures
157
4.14
Optimum moisture content at various coal ash mixtures
157
4.15
Coefficient of permeability coal ash mixtures
at various curing periods
4.16
Coefficient of permeability coal ash mixtures at various
fly ash composition
4.17
164
Variation of unconfined compressive strength of FA-BA
mixtures with curing periods for different fly ash content
4.19
161
Variation of compressive strength of FA-BA mixtures with
FA contents for different curing periods
4.18
160
165
Bar chart on increased in unconfined compressive strength
at different intervals of curing periods for various fly ash
content in FA-BA mixtures
4.20
Shear stress versus horizontal displacement from direct shear
166
xxiii
tests for 50%FA-50%BA mixtures at different normal stress
169
4.21
Peak friction angle of coal ash mixtures at various FA content
172
4.22
Cohesion intercept of coal ash mixtures at various FA content
173
4.23
Peak friction angle of coal ash mixtures at various curing time
173
4.24
Cohesion intercept of coal ash mixtures at various curing time
174
4.25
Shear strength of coal ash mixtures at various FA content
175
4.26
Shear strength of coal ash mixtures at various curing time
175
4.27
Variation of CBR values with curing periods at different
FA content
4.28
Variations of CBR values with FA contents at different
curing periods
4.29
5.5
193
Effect of curing periods on the SiO2 composition at
different FA-BA mixtures
5.4
193
Effect of curing period on the Al2O3 composition at
different FA-BA mixtures
5.3
187
CaO content at various fly ash compositions at difference
curing period
5.2
185
Variation of compression index and swelling index
with curing time
5.1
184
Changes of coefficient of volume compressibility
with curing periods
4.35
184
Coefficient of consolidation versus pressure at different phase in
consolidation test for 70%FA mixture at 28 day curing period
4.34
182
Relationship between coefficient of consolidation with FA
contents and the variation with curing periods for all mixtures
4.33
182
A typical e-log  graph for 70%FA mixture at
28 day curing period
4.32
181
A typical settlement versus square root time curve at 70%FA,
28 day curing period
4.31
179
Shear strength of FA-BA mixtures at various percentages
of FA at 28 day curing periods
4.30
179
194
SiO2 content at various fly ash compositions at different
curing period
194
Percentage of Chemical Content at 50% fly ash
195
xxiv
5.6
Mass loss of Ca(OH)2 for FA-BA mixtures at various
curing periods
5.7
197
Effect of FA compositions on mass loss of Ca(OH)2 at
0, 14 and 28 day curing periods
198
5.8
pH value of FA-BA mixtures at different curing period
199
5.9
Arsenic value of FA-BA mixtures at different curing period
202
5.10
Cadmium value of FA-BA mixtures at different curing period
202
6.1
Time-settlement relationship of soft clay layer and layer
of FA-BA mixtures at various FA compositions
6.2
208
Relationship between settlement of layers of FA-BA mixtures
and FA content at various loading time
211
6.3
Correlation between constant A and time
211
6.4
Correlation between constant B and time
212
6.5
Correlation between constant C and time
212
6.6
Correlation of settlement with FA content at various
loading time
6.7
Time-settlement relationship of footing on 50%FA-50%BA
mixtures at various replacement height ratio
6.8
213
215
Effect of partial replacement of soft clay on the settlement with
layer of 50%FA-50%BA mixtures at various loading time
218
6.9
Correlations of constants c and m with time of loading
219
6.10
Correlation of settlement with height replacement ratio
at various loading time
7.1
Relationship between unconfined compressive strength and
FA content at various loading time for FA>50%
7.2
229
Correlation of unconfined compressive strength with
FA content at various loading time for FA > 50%
7.6
228
Correlation of constant m with loading time at (a) FA> 50%
and (b) FA< 50%
7.5
227
Correlation of constant c with loading time at (a) FA> 50%
and (b) FA< 50%
7.4
227
Relationship between unconfined compressive strength and
FA content at various loading time for FA<50%
7.3
220
Correlation of unconfined compressive strength with
231
xxv
FA content at various loading time for FA < 50%
7.7
Design charts (UCT-Ash Mixtures) of unconfined
compressive strength for FA-BA mixtures
7.8
232
Design chart (Settlement-FRAM) of settlement for
FA-BA mixtures in full Soil replacement
7.9
231
233
Design charts (Settlement-PR50FA) of settlement for
50%FA-50%BA mixtures in partial replacement of
soil with Su = 20 kPa and vertical stress = 216 kPa
234
xxvi
LIST OF ABBREVIATIONS
AAS
-
Atomic absorption spectroscopy
ACAA
-
American Coal Ash Association
ASTM
-
American Society of Testing Material
BA
-
Bottom ash
BS
-
British standard
CCP
-
Coal combustion product
CD
-
Consolidated drained
CU
-
Consolidated undrained
FA
-
Fly ash
FA-BA
-
Fly ash – bottom ash
FBA
-
Furnace bottom ash
FEA
-
Finite element analysis
FGD
-
Flue gas desulfurization
HSM
-
Hardening soil model
JKR
-
Public works department
LEM
-
Linear elastic model
MCCM
-
Modified cam clay model
MCM
-
Mohr coulomb model
OMC
-
Optimum moisture content
PFA
-
Pulverised fuel ash
SEM
-
Scanning electron microscopy
SG
-
Specific gravity
SSM
-
Soft soil model
UCS
-
Unconfined compressive strength
UK
-
United Kingdom
ULS
-
Ultimate limit state
USA
-
United States of America
USCS
-
Unified soil classification system
UTHM
-
Universiti Teknologi Tun Hussein Onn
UTM
-
Universiti Teknologi Malaysia
TGA
-
Thermal gravimetric analysis
xxvii
XRD
-
X-Ray diffraction
XRF
-
X-Ray fluorescence

xxviii
LIST OF SYMBOLS
B
-
Width of foundation
c
-
Cohesion of soil
Cc
-
Compression index
cincrement
-
Cohesion increment
cpeak
-
Peak cohesion
cd peak
-
Peak cohesion for consolidated drained
c‟peak
-
Peak cohesion for consolidated undrained
cresidual
-
Residual cohesion
cd residual
-
Residual cohesion for consolidated drained
c‟residual
-
Residual cohesion for consolidated undrained
Cs
-
Swelling index
cu
-
Undrained shear strength
CU
-
Coefficient of uniformity
cv
-
Coefficient of consolidation
D
-
Depth factor
Df
-
Depth of foundation
DH
-
Depth to firm stratum
D10
-
Effective size
D30
-
Diameter finer than 30 %
D60
-
Diameter finer than 60 %
E
-
Young's stiffness
Eincrement
-
Stiffness increment
Em
-
Young's stiffness of aluminum alloy
Eoed
-
Oedometer stiffness
Ep
-
Young's stiffness of concrete
Eur
-
Unloading stiffness
E50
-
Secant stiffness
F
-
Factor of safety
xxix
g
-
Gravity, 9.81 m/s2
G0
-
Elastic shear modulus
Gref
-
Shear modulus
Gs
-
Specific gravity
H
-
Height of embankment
h
-
Thickness of soil layer
Hs
-
Depth of failure
Ip
-
Plasticity index
kx
-
Horizontal permeability
ky
-
Vertical permeability
Ls
-
Linear shrinkage
mv
-
Coefficient of volume change
N
-
Scale factor
Ns
-
Stability coefficient
t
-
Test time
w
-
Natural water content
wL
-
Liquid limit
wopt
-
Optimum moisture content
wp
-
Plastic limit

-
Slope angle
εa
-
Axial strain

-
Internal friction angle
 peak
-
Peak friction angle
d peak
-
Peak friction angle for consolidated drained
‟peak
-
Peak friction angle for consolidated undrained
 residual
-
Residual friction angle
d residual
-
Residual friction angle for consolidated drained
‟residual
-
Residual friction angle for consolidated undrained

-
Unit weight of soil
d
-
Dry unit weight of soil
dmin
-
Minimum dry unit weight of soil
dmax
-
Maximum dry unit weight of soil
sat
-
Saturated unit weight of soil
xxx
unsat
-
Unsaturated unit weight of soil
ν
-
Poisson ratio
n
-
Normal stress
1
-
Major principle stress
3
-
Minor principle stress

- Shear stress
ψ
-
Angle of dilatancy
xxxi
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
A
Instrumentation calibration
248
B
Hydrometer analysis
251
C
Dry sieving test data
257
D
Specific gravity data
260
E
X- ray diffraction analysis
263
F
Compaction test analysis
272
G
Direct shear test analysis
277
H
Permeability test
283
I
Unconfined compression test
289
J
California bearing ratio test
301
K
One-dimensional consolidation test
304
L
Thermal gravimetric analysis
329
M
Laboratory physical model test results
338
N
Standard error analysis
350