The effects of sample preparation on the pore structure and phase composition of the sulfated cement pastes

•Even under mild temperatures, the oven and vacuum drying approaches partially decomposed the sulfate-induced ettringite and gypsum of the cement pastes.•Ethanol disturbed the thermal stability of the sulfate-induced ettringite and gypsum of the cement pastes.•Solvent exchange via cold isopropanol was the optimum approach to prepare the sulfated cement pastes for the micro-analysis.•A preliminary leaching step was suggested before conducing the MIP measurement of the sulfated cement pastes.