Влияние метакаолина на формирование структуры и свойства композиционного гипсового вяжущего

Abstract

Metakaolin is a promising component for targeted modification of gypsum binder structure. This study used G-5 building gypsum from raw materials of the Ustyurt deposits and metakaolin from kaolins of the Khojakul deposit in the Republic of Karakalpakstan. The optimal mineral composition comprised 78% G-5 gypsum, 16% metakaolin and 6% Ca(OH)₂. An organic modifier complex (Melflux, HEMC, CMC) was also added. Structure development was assessed by compressive strength, average density and softening coefficient at different hardening ages. Between 3 and 28 days, compressive strength increased from 15 to 34 MPa, average density from 1260 to 1330 kg/m³, and the softening coefficient from 0.75 to 0.92. Introducing the modifying additive complex was accompanied by a decrease in porosity from 14% to 9%. The results show that structure control by combining an active mineral additive with organic modifiers can be used to obtain composite gypsum materials with improved performance characteristics.