СТРУКТУРООБРАЗОВАНИЕ ПОРТЛАНДЦЕМЕНТА, МОДИФИЦИРОВАННОГО ОТХОДАМИ МЕТАЛЛУРГИЧЕСКОГО ПРОИЗВОДСТВА

This paper presents the results of a comprehensive study of the effect of a filler based on burnt moulding waste (BMW) and a superplasticiser on the phase composition and structure formation of cement stone at early (1 day) and late (28 days) stages of hardening. X-ray phase analysis (XPA) has established that BFA has a powerful accelerating effect on the hydration of clinker minerals in the first day, which is explained by the adsorption of calcium ions on their surface, while the superplasticiser, on the contrary, slows down this process. A synergistic effect of the combined use of additives has been demonstrated, which negates the retarding effect of the superplasticiser and leads to the intensive formation of hydrate phases at an early stage. By day 28, a significant decrease in the content of portlandite (Ca(OH)2) and an increase in the proportion of amorphous calcium hydrosilicate (C-S-H) by 22% are observed in the modified cement stone, which indicates the occurrence of an active pozzolanic reaction. The data obtained confirm that complex modification allows effective control of the hydration kinetics and the formation of a dense, highly structured cement stone matrix, which is a key factor in improving its strength and performance characteristics.