IMPROVING THE PHYSICO-MECHANICAL PROPERTIES OF MODIFIED CONCRETE BASED ON THE USE OF CHEMICALLY ACTIVATED MICRO-SILICA WITH MICRO-REINFORCING FIBER

The purpose of this work is to study the behavior of activated microsilica in an alkaline environment and the effect of fibers (fibers) on the physical and mechanical characteristics of concrete. The method of microsilica activation in an alkaline medium and stabilization of fine particles by superplasticizer is proposed. For the comparative analysis of the results, in the developed compositions of concrete mixtures were introduced micro-fiber in the form of basalt and polypropylene fiber with consumption from 0.5 to 1% by volume. Testing of specimen prisms of the studied concrete mixtures was carried out with the recommended intensity of loading, fixation and processing of the results. It is established that the samples-prisms of heavy concrete with basalt fiber (BF 0.75%) withstand the maximum load and have a conventional stress intensity factor higher by - 25.91%, bending stress - 25.89% in comparison with the control composition. In relation to samples with polypropylene fibre (PP 0.75%) by 10.85% and 10.87% respectively. The received results of researches of the modified concrete on the basis of application of chemically activated microsilica with microarming fibers possessing the improved physical and mechanical properties and operational indicators, allow recommending it for building of products and designs in heavy conditions of operation.

activated silica fume, microreinforcing fiber, organomineral additive, modified concrete, crack resistance, deformation characteristics, performance indicators