Abstract
A system for in situ time-resolved X-ray diffraction (XRD) under hydrothermal condition has been developed using an originally designed autoclave cell in combination with high-energy X-rays from a synchrotron radiation and a photon-counting pixel array detector. The autoclave cell has welded beryllium X-ray windows. Thus, there are practically no interference signals from the window materials, and it is possible to obtain high-quality XRD patterns with very stable cell temperature and pressure. The system was applied to the formation process of autoclaved lightweight concrete (ALC). Evolutions of both crystalline and non-crystalline phases, structural and composition changes of those phases during the hydrothermal reaction were successfully observed.
