Low-temperature synthesis of binder with belite content

Abstract

Sol-gel methods or hydrothermal treatment in combination with low-temperature burning are used for low-temperature syntheses of hydraulically active dicalcium silicate. The paper describes a two-stage preparation process without the use of an autoclave. In the first phase, the precursors of hydraulically active phases are prepared. In the second phase, burning up to 1000 °C takes place to form a C2S-based binder. Unlike commonly used procedures of the sol-gel method, solid raw materials and water are used. The main raw materials are quicklime and a source of SiO2 and then various activators. X-ray diffraction analysis and electron microscopy methods were used for the research. The resulting binders are similar to hydraulic lime, they achieve low initial strengths, the long-term strengths are satisfactory. It is suitable for the preparation of mortars and plaster mixtures.