Title Page
Abstract
Contents
CHAPTER I. INTRODUCTION 19
1.1. BACKGROUND 19
1.2. SCOPE-ORGANIZATION 23
CHAPTER II. KOREAN RESIDUAL SOIL: HWANGTOH-DEFINITION AND ITS CURRENT STATE - 25
2.1. INTRODUCTION 25
2.2. DEFINITAION OF KOREAN RESIDUAL SOIL: HWANGTOH 27
2.2.1. Residual Soil 27
2.2.2. What is Hwangtoh: General Aspect 29
2.2.3. Geotechnical Properties of Hwangtoh 31
2.3. BENEFITS AND APPLICATIONS OF HWANGTOH 33
2.3.1. Historical Usages 33
2.3.2. Advantages of Hwangtoh: Theoretical Aspects 34
2.3.3. Recent Applications of Hwangtoh 40
2.3.4. Challemges and Limitations of Hwangtoh 42
2.4. SUMMARY AND CONCLUSIONS 43
CHAPTER III. GEOTECHNICAL BEHAVIOR OF BETA-1,3/1,6-GLUCAN TREATED KOREAN RESIDUAL SOIL 45
3.1. INTRODUCTION 45
3.2. MATERIALS AND EXPREIMENTAL METHODS 49
3.2.1. Beta-1,3/1,6-Glucan 49
3.2.2. Beta-1,3/1,6-Glucan Solution Prevaration 50
3.2.3. Hwangtoh: Korean Residual Soil 50
3.2.4. Tensile Strenfgth and Intervarticle Behavior of Beta-1,3/1,6-Glucan 55
3.2.5. Mixing and Curing: Cubic Curimg Test 56
3.2.6. Initial Properties of Beta-1,3/1,6-Glucan-Hwangtoh Mixutres 59
3.2.7. Time Dependent Behavior of Beta-1.3/1,6-Glucan-Hwangtoh Mixtures 62
3.3. RESULTS AND DISCUSSIONS 67
3.3.1. Tensile Strenfgth and Micro Structure of Beta-1,3/1,6-Glucan 67
3.3.2. Tensile Strength of Beta-1,3/1,6-Glucan-Filter Paper Composites 70
3.3.3. Consistency of Hwangtoh and Beta-1,3/1,6-Glucan Mixture 72
3.3.4. Compressibility behavior of Hwangtoh treated by Beta-1, 3/1. 6-Glucan 75
3.3.5. Strength behavior of-Hwangtoh treated by Beta-1,3/1,6-Glucan 93
3.3.6. Beta-1,3/1,6-Glucan Effect on Soil Density. 101
3.3.7. Strength function of Beta-1,3/1,6-Glucan: Microscale Explanation 103
3.3.8. Economic Efficiency of Engineered Hwangtoh using Beta-1,3/1,6-Glucan 107
3.4. SUMMARY AND CONCLUSIONS 110
3.4.1. Summary 110
3.4.2. Conclusions 112
CHAPTER IV. IMPROVEMENT OF KOREAN RESIDUAL SOIL USING BIOPOLYMER MATERIALS: ADDITIONAL STUDY 115
4.1. INTRODUCTION 115
4.2. BIOPOLYMER MATERIALS 118
4.2.1. Xanthan Gum 118
4.2.2. Chitosan 119
4.2.3. Gellan Gum 120
4.3. EXPERIMENTAL METHODS 124
4.3.1. Biopolymer-Hwangtoh Miximg 124
4.3.2. Cubic Curing and Compressive Test 128
4.3.3. Durability Testing (ASTM D 559-03) 128
4.4. RESULTS AND DISCUSSIONS 131
4.4.1. Compressive Strength of Hwangtoh-Biopolymer Mixtures 131
4.4.2. Shrinkage and Dry density of Hwangtoh-Biopolymer Mixtures 134
4.4.3. SEM Image of Hwangtoh-Biopolymer Mixtures 141
4.4.4. Durability of Hwangtoh-Biopolymer Mixtures 147
4.4.5. Environmental and Economic Efficiencies of Biopolymers 151
4.5. SUMMARY AND CONCLUSIONS 155
4.5.1. Summary of Hwangtoh-Biopolymer Mixtures 155
4.5.2. Conclusions 157
CHAPTER V. PRACTICAL APPLICATIONS 159
5.1. INTRODUCTION 159
5.2. PROTOTYPE: ECO-FRIENDLY INTERIOR MATERIAL 161
5.2.1. Materials 161
5.2.2. Manufacture 161
5.2.3. Curing Performance 165
5.2.4. Quality Testing (Flexural Test: ASTM D1635-00) 167
5.2.5. Verification 171
5.2.6. Economic Analysis 174
5.3. POSSIBLE APPLICATIONS 175
5.3.1. Bioclogging 175
5.3.2. Carbon Dioxide Storage 176
5.3.3. Pavement: Earthzyme 177
5.4. CONCLUSIONS 178
CHAPTER VI. CONCLUSIONS AND RECOMMENDATIONS 179
6.1. CONCLUSIONS 179
6.2. RECOMMENDATIONS AND FUTURE RESEARCH 183
REFERENCES 185
요약문 209
CURRICULUM VITAE 215
Table 2.1. Geotechnical Properties of Hwangtoh (Ha-dong, Korea). 32
Table 2.2. XRF (X-Ray Fluorescence) result of Hwangtoh (Ha-dong, Korea). 32
Table 2.3. Energetic index of construction materials 37
Table 2.4. Carbon dioxide emission of construction materials 38
Table 3.1. Typical beta-glucan materials. 51
Table 3.2. Medical applications of beta-glucan. 52
Table 3.3. Solutions used for compaction test. 54
Table 3.4. Testing setup of compressibility test of β-1,3/1,6-glucan-Hwangtoh mixtures. 65
Table 3.5. Tensile strength properties and results of β-l,3/1,6-glucan-filter paper composites. 71
Table 3.6. Experimental results of the compressibility and elastic wave variation of β-1,3/1,6-glucan treated Hwangtoh. 81
Table 3.7. Economic and environmental analysis of OPC and β-1,3/1,6-glucan treated Hwangtoh. 109
Table 4.1. Mixing conditions of Biopolymer-Hwangtoh mixtures. 127
Table 4.2. Economic and environmental analysis of OPC and β-1,3/1,6-glucan treated Hwangtoh. 153
Table 4.3. Characteristics summary of biopolymer treated Hwangtoh. 156
Table 5.1. Standard criteria of interior boards (KS F3504 2007). 163
Table 5.2. Sample properties before and after curing. 166
Table 5.3. Flexural test results. 169
Figure 2.1. Diagrammatic representation of soil formation processes 28
Figure 2.2. Structure of 1: 1 layer of Si-tetrahedral and Al-octahedral sheets 30
Figure 2.3. Honey-comb structure of Hwangtoh 30
Figure 3.1. Molecular structures of typical beta-glucans. 53
Figure 3.2. Schematic view of the cubic curing device. 57
Figure 3.3. Specimen mixing and compacting equipments. 58
Figure 3.4. Specimen molding. 58
Figure 3.5. Cone penetrometer test device. 63
Figure 3.6. Schematic diagram of wave based compressibility testing device. 64
Figure 3.7. Example of compressive strength testing on cubic cured samples 66
Figure 3.8. SEM imagaes. 69
Figure 3.9. Liquid limit behavior of β-1,3/1,6-glucan treated Hwangtoh. 74
Figure 3.10. Elastic wave velocities with time and load step increment 77
Figure 3.11. Elastic wave velocities with time and load step increment 78
Figure 3.12. Elastic wave velocities with time and load step increment 79
Figure 3.13. Vertical shear wave velocity variations, with the increase of applied vertical effective stress. The results show that the α factor increases as the concentration of β-1,3/1,6-glucan increases. 82
Figure 3.14. Void ratio variations with time and load step increment. 85
Figure 3.15. e-log σ relationship of β-1,3/1,6-glucan affected Hwangtoh. The results indicate the independency between compressibility and presence of β-1,3/1,6-glucan. 87
Figure 3.16. Void ratio and shear wave velocity relationship of β-1,3/1,6-glucan treated Hwangtoh. 89
Figure 3.17. Void ratio and compressive wave velocity relationship of β-1,3/1,6-glucan treated Hwangtoh. 91
Figure 3.18. Schematic diagram of the inter-particle behavior between β-1,3/1,6-glucan and Hwangtoh particles, under axial and shear strain. 92
Figure 3.19. Compressive strength and stiffness (Young's modulus, E) variation of β-1,3/1,6-glucan-Hwangtoh mixtures according to curing temperature and time. 96
Figure 3.20. Compressive strength against dry density. 99
Figure 3.21. Strengthening results using β-1,3/1,6-glucan, compared to 10% cement mixed Hwangtoh. 100
Figure 3.22. Compaction test results of β -1,3/1,6-glucan treated Hwangtoh. 102
Figure 3.23. SEM images of the strengthening mechanism of β-1,3/1,6-glucan. 105
Figure 3.24. Adsorption and strengthening phenomena induced by β-1,3/1,6-glucan polymers. 106
Figure 3.25. Summary. Flow chart of the studies performed in this chapter. 111
Figure 4.1. Research procedure of Chapter 4. 117
Figure 4.2. Structure of Xanthan gum. 122
Figure 4.3. Molecular structure of Chitosan. 123
Figure 4.4. Structure of Gellan gum. 123
Figure 4.5. Strength and stiffness behavior of biopolymer treated Hwangtoh. 137
Figure 4.6. Drying shrinkage behavior of biopolymer treated Hwngtoh. 138
Figure 4.7. Normalized volumetric strains with initial water content, which indicates the shrinkage tendency of soil affected by different type of biopolymers. 139
Figure 4.8. Compressive strength (hallow points) and dry density (bold points) variation of biopolymers (Xanthan gum, Gellan gum, Chitosan, and Beta-glucan) treated Hwangtoh. 140
Figure 4.9. SEM image ofXanthan gum-Hwangtoh mixed sample. 142
Figure 4.10. SEM image of Chitosan-Hwangtoh mixture. 144
Figure 4.11. SEM image of Gellan gum-Hwangtoh mixture. 146
Figure 4.12. Durability of biopolymer treated Hwangtoh. 149
Figure 4.13. Example of the durability test (1st and 2nd cycle of wetting and drying).(이미지참조) 150
Figure 4.14. Expected economic efficiency of biopolymers related to the growth of global carbon emission trade. 154
Figure 5.1. Photographs of prototype samples before and after curing. 164
Figure 5.2. Flexural test results. 168
Figure 5.3. Flexural strength distribution and Korean industrial standard. 170
Figure 5.4. Natural and gypsum mixed Hwangtoh boards. 172
Figure 5.5. Flexural strength values of KS F3504 standard, natural Hwangtoh, β-1,3/1,6-glucan-Hwangtoh, and gypsum-Hwangtoh boards. 173