About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Phase Transformations in Ceramics: Science and Applications
|
| Presentation Title |
The Potential of Solid-State NMR Investigations for Characterizing Phase Transformations in Calcium Aluminate Cements During the Hydration Process |
| Author(s) |
Nicole Bonk, Ali Masoudi Alavi, Peter Quirmbach |
| On-Site Speaker (Planned) |
Nicole Bonk |
| Abstract Scope |
The hydration of calcium aluminate cements (CAC) is a complex process where various formed hydrate phases afterwards decisively determine the material's mechanical properties of refractories. Focus is the systematical investigation of time-dependence during hydration, characterizing the formation and transformation of hydrate phases in commercial refractory cements. The innovative approach is the first-time implementation of semi-quantitative solid-state NMR (ss-NMR) in CAC systems. To decidedly capture characteristic hydration phases, the reaction course is monitored using thermal analysis (TGA/DSC) to identify points for stopping hydration. Subsequent characterization combines powder X-ray diffraction (PXRD), Rietveld refinement, and particularly ss-NMR. ss-NMR enables the semi-quantification of hydrated and non-hydrated constituents as well as precise phase identification through spectral deconvolution. A significant advantage is the detection of X-ray amorphous phases, which cannot be identified only by PXRD measurements. This study demonstrates the potential of ss-NMR for an in-depth scientific understanding, for purposeful material optimization of "engineered" refractories. |