Physico-chemical research of the processes of hydration of cements

Abstract

The activating effect of phosphoanhydrite on cement hydration is strongly supported by the results obtained from various physico-chemical analyses, including IR spectroscopy, X-ray phase analysis, and differential thermal analysis. IR spectroscopy revealed significant differences in the hydration products of cement with and without phosphoanhydrite. The presence of phosphoanhydrite led to distinct absorption bands in the IR spectra, indicating a higher concentration of Portland cement hydrate compounds and calcium the activated cement. This observation suggests that hydrosilicates in phosphoanhydrite plays a vital role in promoting the formation of these hydration products, leading to enhanced cement activation.X-ray phase analysis further confirmed the activating effect of phosphoanhydrite. The diffraction patterns of the hydrated cements showed a remarkable increase in the analytical lines corresponding to Ca(OH)2 when phosphoanhydrite was present. This indicates a higher content of this phase in the activated cement, reinforcing the notion that phosphoanhydrite contributes to the accelerated hydration process.Differential thermal analysis provided additional evidence of the activating effect of phosphoanhydrite. The DTA curves exhibited higher hydration levels for the cement activated with phosphoanhydrite compared to the control cement. This was indicated by an increased percentage of bound water and a greater mass loss at 140°C, demonstrating the more extensive hydration of the activated cement.Taken these physico-chemical analyses consistently demonstrate the activating effect of phosphoanhydrite on cement hydration. The unique properties of phosphoanhydrite facilitate the formation of hydration products, such as Portland cement hydrate compounds and calcium hydrosilicates, leading to an accelerated and more efficient hydration process.