For the solvent exchange, the cement pastes are crushed and ground to fine powder. The
prepared powders are centrifuged three times for 20 minutes with a solvent to remove the
excess water and to stop the hydration. At the end of every cycle, the solvent is removed and
replaced by fresh one. Immediately after the last cycle, the samples are dried at 40°C for 24
hours under vacuum with a pump with an ultimate vacuum of 10mbar. Three types of organic
solvents are used: pure ethanol, pure methanol and three cycles of pure ethanol followed by
one cycle of pure ether to remove the ethanol.