Phase composition of belite cements of increased hydraulic activity

Building Materials

The work is devoted to resource-saving technology development of belite cements. To solve the problem of slow hardening of belite cements, the influence of clinker phases on hydration and structure formation of binders has been studied. Composition and structure of substances were analyzed using X-ray, differential thermal methods and microscopy. Dependence of belite cements’ design strength with a saturation rate of SR = 0.73–0.80 on the content and properties of C3S alite was determined. Increase in C3S activating ability during formation of alite, based on natural silicates structures was revealed. It was found that the combination of C2S belite and calcium silicoaluminate C6A4MS in cement stimulates hydration and hardening processes. Intensive formation of stable hexagonal hydroaluminates and hydrogelenite provides a high rate of structure formation. Advantages of co-hydration of C2S with C3S and C6A4MS were realized in the mixed cement obtained from belite and aluminate clinkers. Studies of clinkers based on skarn-magnetite ore dressing waste indicate the preference of technogenic raw materials for improving belite cements technology.