microsilica

The use of rubber crumb from used tires in concrete as a partial replacement of natural aggregates is an ecologically oriented direction of their utilization. When rubber crumb was added to Portland cement, a decrease in strength was observed. Modification of rubber-containing Portland cement systems with a complex organic and mineral additive makes it possible to compensate for the loss of compressive strength and provide increased impact strength. Samples without rubber show high strength but are characterized by fragility and sudden destruction of the material.

The physico-chemical methods of the research of hydrated cement by mechanoactivated bonding substance with organo-mineral additive (microsilica + C-3) was presented. It was explored the influence of the additive into the kinetics of formation lowly basic calcium hydrosilicate.

The work deals with the modification of mortars by small quantities of nanodispersed material. The effect of amorphous nanosilica on Portland cement hydration and hardening has been investigated. The amorphous nanosilica is compared with the known mineral additive – microsilica.

The work deals with the analysis and evaluation of different methods of pozzolanic activity determination in order to rationally use ash in cement. The most optimum diagnostic method has been suggested. The possibility of increasing fluidal fly ash activity has been established using the synthetic nanosilica.