Critical investigation of TGA sample preparation for composite cements

Thermogravimetric analysis (TGA) is a frequently used technique to investigate the phase assemblages of hydrated cements. However the obtained results are sensitive to the sample preparation. A commonly used technique for stopping hydration is solvent exchange during which the free water is replaced by solvents which are then removed by evaporation. One of the most crucial steps in the sample preparation is the drying. Drying hydrated cement samples can cause carbonation and decomposition of hydration phases. Different solvent exchange and drying methods were tested in order to minimize carbonation and decomposition of hydration phases.