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CHAPTER 4 FE-CONTAINING HYDRATES IN HYDRATED CEMENT 4.1.2. Characterization of hydrated cement using standard analytical techniques The hydration of two different cements, OPC and HS, was studied to determine the Fe speciation at various stages of the hydration process. Both cements contained roughly 5 wt.% Al2O3 while their Fe2O3 content differed widely. The cement OPC had a Fe2O3 content of 3 wt.%, while the HS contained about 7 wt.%. The progress of hydration and appearance/disappearance of the main cement phases can easily be followed using standard analytical techniques like XRD, TGA and SEM. During the hydration the peaks of the reactive clinkers phases C3S and C3A diminished fast, while C2(A,F) and C2S peaks persisted over longer periods of time (Fig. 67). Fig. 67 XRD patterns of OPC (+) and HS (*) cements hydrated at 20 °C. 149
CHAPTER 4 FE-CONTAINING HYDRATES IN HYDRATED CEMENT Gypsum and anhydrite were consumed within the first day. The main hydrates formed during hydration were C-S-H and portlandite. In addition, the formation of AFt and AFm (monosulfate in the case of OPC and monocarbonate for the calcite containing HS) was observed. The formation of ettringite and AFm phases was observed within 1 day (Fig. 67 and Fig. 68). The weight loss in the TGA-DTG curve between 100°C and 240 °C indicates the presence of ettringite, C-S-H and AFm phases (Fig. 68). weight loss in % differentiated relative weight 100 90 80 70 -0.1 -0.2 gypsum Ettringite AFm phases C-S-H portlandite 100 200 300 400 500 600 700 800 Temperature (°C) carbonate Fig. 68 TGA-DTG curves of OPC (+) and HS (*) cements hydrated at 20 °C. unhyd+ 1 day+ 28 days+ 150 days+ 3 years+ 3 years* Temperature had a significant influence on the hydration process (Fig. 69 and Fig. 70). While C-S-H and portlandite were still the main phases formed in both OPC and HS after hydration for 1 year at 50 °C ettringite was not detected, but AFm phase was detected in both the OPC and HS at 2θ ~ 11.30° (Fig. 69). The AFm phase peak was in between the 150
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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 124 and 125: CHAPTER 3 SYNTHETIC FE-CONTAINING H
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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
Page 200 and 201: differentiated relative weight Weig
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
Page 218 and 219: Intensity (arb. Units) P Fe 2O 3 R
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Page 222 and 223: REFERENCES REFRENCES [1] H.F.W. Tay
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REFRENCES [29] M. Vespa, R. Dähn,
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REFRENCES [54] M. Balonis, B. Lothe
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REFRENCES [81] H.F.W. Taylor, Cryst
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REFRENCES [107] K. Kyritsis, N. Mel
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REFRENCES [134] M. Wilke, F. Farges
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CURRCULUM VITAE Curriculum Vitae Na
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