Вплив механічної активації мінеральних складових на властивості полегшених складів цементних сухих сумішей для підлог

Abstract

The technology of manufacturing and use of dry building mixtures (DBM) requires a high fineness of grinding components. High requirements for the economy of material resources and the need for a wide range of cement solutions require the study of methods that will allow to obtain a dry mixture with a given set of high performance characteristics while reducing the cost of cement binder and expensive chemical functional additives. The share of the mineral component (astringent, filler) in the formulation of DBM is usually 95%. Therefore, mechanical activation is one of the effective ways of modifying and optimizing the properties of multi-component dry mortars, especially for the formation of solutions of porous structure. In addition, in the production of dry building mixtures, most mineral fillers require additional grinding to a certain granulometry. Unlike organic, mineral powders, after mechanical activation, can actively change granulometry, develop the surface of grains, obtain a certain activity, electric charge of the surface, change the shape of particles and the force of grafting between them, abrasiveness, etc. The effect of mechanical activation of mineral components on the properties of lightweight compositions of cement dry building mixtures has been investigated. It was established that the mechanical additional grinding of carbonate fillers to the required granulometry allows to obtain an active filler for the lightweight DBM. It was found that the addition of fly ash of thermal power plants at the stage of mechanical activation of a given filler and subsequent joint grinding with cement increase the strength of hardened solutions with porous structure. The introduction of high-plastic clay and quartz sand together with surface-active and foamforming additives into a dry mixture at the stage of mechanical activation can improve the rheology and plastic strength of the prepared porous solution. Theoretical and experimental studies resulted in obtaining the compositions of the lightweight mineral dry building mixtures on the basis of Portland cement and conventional dense fillers (quartz sand, limestone, clay, fly ash) with high rheological activity, the strength up to 15 MPa, and improved thermal and acoustic characteristics. This determines the possibility of using these mixtures for the elements of floors in civil buildings.