THE ROLE OF CALCITE IN DECORATIVE SLAG-ALKALI CEMENTS

Abstract

The results of studies of the influence of a carbonate additive in a significant amount (³ 24%) on the physical-mechanical, technological and operational properties of slag-alkaline decorative cements and mortars based on them are presented. A positive effect of the addition of calcium carbonate in the optimal amount on the processes of structure formation of decorative slag-alkali cement stone was established, which was expressed in deepening and accelerating the processes of hydration, reducing the migration and mass transfer of sodium ions to the surface of mortars and concretes and their deeper chemical binding, homogeneity of the microstructure. The addition of finely dispersed calcite in the optimal amount helps to increase strength, density, frost resistance, and reduce shrinkage. Potentially, this can have a positive effect on corrosion resistance, impermeability. It has been established that the water-holding capacity of slag-alkaline decorative mortars freshly prepared in laboratory conditions is 95…97%. The introduction of CMC additive increases this indicator to the level of 96...98.6% with the improvement of the rheological properties of the solution. In addition, the presence of a water-retaining additive potentially reduces the risk of efflorescence and cracking.