Possibilities of using metakaolin to reduce the cement stone shrinkage

The analysis of literature on the topic of research was performed. The main causes of cement stone and concrete shrinkage were identified. It was found that the shrinkage is caused, first of all, by the combined action of capillary forces and forces appearing when water is removed from the layers formed between the crystals of the cement stone newgrowths. The effective method for reducing the cement stone and concrete shrinkage was considered. The desired effect was achieved through the introduction of modifying additives, including sulfate ions and aluminates, which allow to form various modifications of calcium hydrosulfoaluminate. The main hypothesis was formulated about the effect of metakaolin on the shrinkage deformation of cement stone and concrete, according to which the addition of a combination of the additive with superplasticizer and gypsum would theoretically contribute to the reduction of the shrinkage deformations.