Belay Zeleke Dilnesa - Eawag-Empa Library

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CHAPTER 4 FE-CONTAINING HYDRATES IN HYDRATED CEMENT intensities of the spectra, thus indicating similar symmetry. Similarly, no siginificant difference were observed between C3FSH4 and C3(A,F)SH4. In this study, Fe-containing phases were identifyed in hydrated cement based on EXAFS spectra due to the capability of the technique to identify poorly crystalline phases and those with low Fe concentrations. The EXAFS spectra of possible stable Fe-containing phases like the clinkers (C4AF and C2F), Fe(OH)3, C4FcH12, C6Fs3H32, C3(A,F)SH4, C3FSH4 and Fe-hydrotalcite were used as a reference compounds. Other possible Fe- containing phases like Al/Fe-solid solution AFm, AFt and hydrogarnet were not considered as the feature of the spectra are nearly identical with those of the pure Fe- containing AFm, AFt and hydrogarnet phases. Also C4FsH12 was not used as reference as the features are nearly identical with those of C4FcH12. Fig. 76 Fe K-edge XANES spectra of Fe-containing hydrates. The broken lines indicate the position of related spectral features. 159
CHAPTER 4 FE-CONTAINING HYDRATES IN HYDRATED CEMENT Fig. 77 k 3 -weigthed experimental bulk-EXAFS spectra of Fe-containing phases used as reference compounds. The broken lines indicate the position of related spectral features. 4.1.3.2. Identification of Fe-containing hydrates The EXAFS spectra of hydrated OPC and HS were collected at the Fe K-edge (7112 eV). Fig. 78 and Fig. 79 show the EXAFS spectra of hydrated OPC after different hydration times aged at 20 and 50 °C. The features of the spectra change as the hydration process progresses with time thus indicating the formation of different Fe-containing phase during hydration. The unhydrated cement spectra only contain the ferrite clinker (C2(A,F)). The spectra of OPC hydrated for 4 and 8 hours are similar which indicates that the same Fe-containing phases present in similar amounts contributed to the composed spectra. A small difference was observed between the unhydrated cement spectra and hydrated spectra (4 and 8 hours) at k ~ 6-7 Å. However, for OPC hydrated at 50° C, the difference is more significant at 16 hours hydration. Note that in all cases the spectral 160
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Fe-containing hydrates and their fa
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The measured composition of the liq
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ZUSAMMENFASSUNG Thermodynamische Mo
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konnten die Fe-haltigen Hydrate im
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I owe to thank all the laboratory t
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Table 19 Compositions of Al/Fe-mono
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LIST OF FIGURES Fig. 1 Calculated v
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Fig. 34 Calculated solubility produ
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Fig. 62 Calculated solubility produ
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Table of Contents TABLE OF CONTENTS
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TABLE OF CONTENTS 3. SYNTHETIC FE
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TABLE OF CONTENTS 3.5.4. Solid solu
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1 INTRODUCTION CHAPTER 1 INTRODUCTI
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CHAPTER 1 INTRODUCTION be formed. T
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cm 3 /100 g cement 85 80 75 70 65 6
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CHAPTER 1 INTRODUCTION 1.4 Characte
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CHAPTER 1 INTRODUCTION Fig. 4 Sampl
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CHAPTER 1 INTRODUCTION Identificat
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CHAPTER 2 MATERIALS AND METHODS han
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3CaOAl2O3 + 6H2O → 3CaOAl2O36H2O
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CHAPTER 2 MATERIALS AND METHODS Tab
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CHAPTER 2 MATERIALS AND METHODS 2.2
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CHAPTER 2 MATERIALS AND METHODS fil
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CHAPTER 2 MATERIALS AND METHODS at
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CHAPTER 2 MATERIALS AND METHODS the
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CHAPTER 2 MATERIALS AND METHODS 0 t
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CHAPTER 2 MATERIALS AND METHODS Tab
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CHAPTER 2 MATERIALS AND METHODS 2.3
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CHAPTER 2 MATERIALS AND METHODS The
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CHAPTER 3 SYNTHETIC FE-CONTAINING H
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a). b). CHAPTER 3 SYNTHETIC FE-CONT
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o layer thickness (A) 8.0 7.8 7.6 C
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Phase log KSo CHAPTER 3 SYNTHETIC F
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volume [cm 3 ] 700 600 500 400 300
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Intensity [arb. units] Fe-Fr CHAPTE
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Page 134 and 135: CHAPTER 3 SYNTHETIC FE-CONTAINING H
Page 172 and 173: CHAPTER 4 FE-CONTAINING HYDRATES IN
Page 182 and 183: (Al+Fe)/Ca (Al+Fe)/Ca 0.8 0.6 0.4 0
Page 188 and 189: k 3 (k) CHAPTER 4 FE-CONTAINING HYD
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Page 202 and 203: Early reaction CHAPTER 4 FE-CONTAIN
Page 204 and 205: weight loss in % differentiated rel
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Page 210 and 211: Speciation of iron(III) in hydrated
Page 212 and 213: 5. GENERAL CONCLUSION AND OUTLOOK
Page 214 and 215: Techniques XRD X-ray diffraction TG
Page 216 and 217: APPENDIX APPENDIX Appendix A: Addit
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Page 222 and 223: REFERENCES REFRENCES [1] H.F.W. Tay
Page 224 and 225: REFRENCES [29] M. Vespa, R. Dähn,
Page 226 and 227: REFRENCES [54] M. Balonis, B. Lothe
Page 228 and 229: REFRENCES [81] H.F.W. Taylor, Cryst
Page 230 and 231: REFRENCES [107] K. Kyritsis, N. Mel
Page 232 and 233: REFRENCES [134] M. Wilke, F. Farges
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CURRCULUM VITAE Curriculum Vitae Na
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