ОЦЕНКА ЭФФЕКТИВНОСТИ МОДИФИКАЦИИ ГЕОПОЛИМЕРНОЙ СИСТЕМЫ МИНЕРАЛЬНЫМИ НАПОЛНИТЕЛЯМИ С ТОЧКИ ЗРЕНИЯ ФОРМИРОВАНИЯ ПРОЧНОСТНЫХ ХАРАКТЕРИСТИК

Abstract

Geopolymers, due to their positive features, can fully compete with traditional Portland cement analogues, and often have other valuable properties that can significantly expand the scope of application of mineral binders for construction purposes. This seems possible due to a wide range of raw materials of different origins, as well as a result of the use of modifying additives of different nature, morphology and, as a consequence, functionality. As part of this work, the effect of some formulation factors was studied: the concentration of the alkaline activator, as well as the type and content of the modifying agent on the strength characteristics of a geopolymer binder based on fly ash. The results of the study made it possible to establish that an increase in the concentration of the alkaline component negatively affects the effect of the modifier. Modification of the geopolymer binder with Portland cement in the NaOH concentration range from 9 to 13% leads to strengthening of the geopolymer system with an increase in its content. With a further increase in the concentration of the alkaline activator, it initiates a softening effect from the introduction of Portland cement. In turn, modification with kaolin and metakaolin leads to a decrease in compressive and bending strength characteristics throughout the entire range of alkali concentrations under consideration. Moreover, the higher the alkalinity of the geopolymer matrix, the more pronounced the softening effect takes place.