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

Abstract

Sample preparation is a critical step in the microstructural analysis of a sulfated cement paste because the sulfate attack’s products such as ettringite, gypsum, etc. are highly vulnerable under pore solution extraction. Hence, carelessness at this step can easily lead to misleading conclusions concerning the aftermaths of the sulfate attack. Considering this issue, the presented research tended to identify the optimum sample preparation method which causes the least interference in the phase composition and porosity analyses of the sulfated cementitious materials. To do so, sulfated cement pastes were dried and prepared via various approaches, and the effects of each of such approaches were assessed on the micro-analyses results. Powder X-ray diffraction, thermogravimetry, Fourier transform infrared spectroscopy and mercury intrusion porosimetry were the employed micro-analysis techniques. The solvent exchange approach via cold isopropanol was identified as the optimum preparation technique for the sulfated cement pastes.