| Summary: | The primary objective of this thesis was the study of the synthesis conditions, crystallization and the resultant parageneses of technically important, crystalline compounds in the system CaO-SiO_2-H_2O. Herewith we have set a foundation for the systematic development and/or recycling of building materials based on C-S-H-phases. For the first time the Rietveld method as an analytical tool was systematically applied to such materials. A suitable refinement strategy was developed, whereby possible sources of errors and specific problems were discussed. The successful application of the Rietveld method requires precise knowledge of the crystal structures of all C-S-H-phases. For this purpose, the structural systematics in the C-S-H system have been critically reviewed and updated. Additionally all C-S-H minerals have been sorted according the degree of polymerization of their silicate anion structure. In this study both natural and synthetic calcium silicate hydrates were investigated. In the comparative structural study we have used such methods as XRD, DTA, IR and Raman spectroscopy, electron microprobe (EPMA), ESEM, TEM, AFM and quantitative phase analyses with the Rietveld method. Among the natural C-S-H-phases studied here were complex multiphase samples from Greenland (''mixed layering'' of reyerite and gyrolite), Fuka (Japan, fine intergrowth of foshagite and calcite) and from the Urals (14Aa-, 11Aa-tobermorite, clinotobermorite und diopside). Despite many investigations there are phases among the C-S-H-minerals whose structures are still poorly known or not well understood. In this study the structures of 10Aa-tobermorite, Z-phase, xonotlite and foshagite have been in particular investigated further. To summarize, a parallel between natural and technical C-S-H phases was made in this work. For this purpose, natural calcium silicate hydrates, synthetic C-S-H phases in pure systems, hydrated and subsequently hydrothermally treated clinker minerals and hardened cement pastes have been examined. The results obtained regarding synthesis conditions, parageneses, thermal behavior and the influence of the carbonation contribute generally to a better understanding of the complicated phase relationships in cement systems. (orig.) 277 refs. Available from TIB Hannover: ZA 5141(6877) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische Informationsbibliothek SIGLE DE Germany
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