Mechanochemical Activation of the C-S-H binder Celitement

The hydraulic binder Celitement is produced by a mechanochemical activation of an X-ray amorphous CSH phase. This process step not only chemically activates the material, but also reduces its specific surface area. Thus, both strength and workability of Celitement based systems can be controlled. In this paper the effect of the duration of the activation milling on chemical and microstructural changes of Celitement is focused. Therefore ATR-FTIR Spectroscopy, Thermogravimetry, Heatflow Calorimetry, Scanning Electron Microscopy and BET (N₂) specific surface area measurements are used aside classical experiments on the flow spread and compressive strength of Celitement based mortars. As a result, it is shown that micro structural changes and chemical activation occur already at the beginning of the activation milling and significantly influence the practical performance of mortars.