Synthesis, characterisation and hydration of ternesite

Abstract

Ternesite has recently been shown to exhibit reactivity, especially in the presence of aluminum. In this article, the preparation and hydration of ternesite was studied. The dopants were incorporated during the synthesis of ternesite. The incorporation of dopants affected the synthesis of ternesite and CaF2 was most effective in achieving high phase purity. X-ray diffraction, thermal gravimetric analysis, fourier-transform infrared spectroscopy and scanning electron microscopy were conducted to investigate the hydration of ternesite. The influence of curing temperature and humidity on the hydration of ternesite and ternesite-aluminate blends were also explored. The results demonstrated that the incorporation of ye’elimite resulted in the formation of ettringite and monosulfate while the incorporation of C3A caused the formation of katoite, portlandite and monosulfate. In the presence of aluminates, the hydration kinetics of ternesite was accelerated by increasing curing temperature. Curing with high humidity was advantageous to the hydration of ternesite and ternesite-ye’elimite blend but inhibited the hydration of ternesite-C3A blend.