Effect of additives SiC on the hydration and the crystallization processes of gypsum

Abstract

The properties of gypsum materials are largely determined by the structure of the matrix. Additives introduced into the gypsum matrix affect the hydration, size, and morphology of the crystals, the state of the interface and overall porosity. As a result, gypsum binders with increased water resistance and strength are possible to make.This work presents one part of the study of the additives’ influence on hydration and crystal formation processes. The adding of micro and nanoadditives SiC accelerates the hydration and crystallization of gypsum and increases the length of crystals. Dispersed additives act as crystallization centers, and due to the increased specific surface area, they introduce excess energy into the crystallizing system. More significant changes are observed with the joint introduction of micro and nanoadditives and plasticizer. The crystal growth rate along all axes is more balanced, the length and thickness of the crystal increase by 3–5 times, and the crystals grow stronger. The results obtained in the study are useful for understanding the concept of the action of micro and nanoadditives, separately and together with a plasticizer on the processes of crystal formation.