Determination of the degree of hydration of Portland cement using three different approaches: Scanning electron microscopy (SEM-BSE) and Thermogravimetric analysis (TGA)

Abstract

Cement paste hydration is a complex physical-chemical process. The aim of this paper is to use three approaches to determine the degree of hydration: portlandite quantification, scanning electron microscopy and bound water quantification. In order to investigate the physical-chemical and mechanical properties, as well as the hydrates generated. Portland cement was synthesized and characterized in the laboratory. At all hydration durations, the portlandite quantification method and SEM-BSE image analysis show similar results. The method of SEM images analysis requires time to gather and process images, but is unaffected by the type of hydrates produced. The bound water quantification method gives a lower degree of hydration than two other methods at all hydration times. To test the reliability of these procedures, the compressive strength was calculated based on the degree of hydration. The results indicate that the portlandite quantification method and SEM-BSE image analysis are more accurate than the bound water quantification approach in terms of reproducing the experimental results.