Dust fraction of granite crushing screenings as a medium of micro/nanoparticles engaged in structural formation of cement concrete.

The dust fraction of the granite crushing screenings is considered and evaluated as a carrier of microsize and nanosized components engaged in the structure formation of cement stone and concrete. The genesis of the pulverized fraction and the identification of its composition and specific properties are given. The paper also analyzes the nature of mechanical, mechanochemical, physical and chemical activity and the role of the pulverized fraction of screening in the processes of cement hydration and structure formation of cement stone. The microsized component is regarded as a filler in the cement that is a part of the fine-grained concrete mixture. The nanoscale component is analyzed as a silica-containing additive capable to provide nanomodification of the hydrated cement structure. Experimental data and quantitative estimates of the influence of the dust fraction on the hardening dynamics and the strength of fine-grained concrete are presented