On the experience of using metakaolin as a structuring additive in cement composites

This article presents the study of the metakaolin influence on the physical and chemical characteristics of cement compositions. The metamorphism of hydration products in the structure of cement stone modified with this additive is described. The optimal concentration of the additive is established which provides the maximum increase in the strength of cement concrete both at the early stages of hardening and at the design age. The methods of IR spectroscopy, differential thermal analysis, X-ray microanalysis, and the study of the microstructure were used to study the properties of the obtained material. It was found that the use of metakaolin as a structuring additive enhances the hydration of cement due to the absorption of calcium hydroxide and the formation of a new phase in the form of calcium aluminosilicate hydrates, which leads to an increase in strength of the modified cement stone.