FORMULATION OF SELF-COMPACTING CONCRETE USING RAW MATERIALS OF THE NORTH CAUCASUS

Aim. The paper considers the issues associated with the development of formulations of self-compacting concrete.Methods. The basis of the preparation of such concrete is necessary to use effective modern modifiers that improve the rheological properties of the concrete mix and promote enhancement of its physical - mechanical parameters, and fine mineral powders of natural origin. Particular attention is paid to aggregate the results of obtaining graded aggregate obtained by mixing large and small Alagir Chervlensk sand.Results. Cements studied various manufacturers have been allocated the most appropriate of them, it is Portland cement CEM I 42,5N «Chechensemen» and «Novoroscement». Crushed granite was used from diabase rock fractions of 5-20 mm, which was purchased for testing of the RNO-Alaniya. Developed formulations self-compacting concrete, characterized by an intensive set of concrete strength in the early days of its hardening: at the age of 7 days RSZH concrete reaches up to 80% of project strength.Conclusion. The results of the research in this area showed that the raw material potential of North Caucasus Federal District produces selfcompacting concrete class B 25 and B90 and later for monolithic construction, including high-rise

LOW WATER CEMENTS BASED ON ACTIVE MINERAL ADDITIVES OF VARIOUS ORIGINS

We consider the problems associated with the development of high-efficient binders. It was found that the mortars and concretes important indicator is the ratio of binding properties of cements with a so-called ”specific consumption of aggregates. ” It was found that the activity of Portland cement in the past decade has increased slightly and is 50-55 MPa; physical and technical characteristics of high-quality graded fine and coarse aggregates remained unchanged. It substantiates the relevance of the development of new types of cements for high-strength and high-quality concrete with active mineral additives and an effective superplasticizers. It is proved that the use of the obtained cements of low water through the use of active mineral additives of different origin, allows to obtain high-quality concrete with strength class from B60 to B100, reduce the need for water-mortar and concrete mixtures of 25-30% for equal mobility

THE INFLUENCE OF GRANULOMETRY OF VELLA SANDS ON THE PROPERTIES OF REPAIRED MODIFIED COMPOSITIONS

Objectives. Study of the problems associated with the possibility of the effective use of substandard sand dunes of the Shelkovskoye deposit as a mineral additive for the production of fine-ground binders and the enrichment of rock crushing screenings.Method. They are based on the established principles of the theory of hardening repair modified compositions with the integrated use of vibroactivated mineral and polymer components, and in particular, the filled system “Portland cement - sandstone - C-3”, as well as mathematical logic and technology of composite materials. The studies were carried out taking into account current state standards and recommendations.Result. The results of the study of local sand dunes and rock crushing screenings are presented for obtaining enriched aggregates with optimal granulometry and properties. Repair compositions were obtained with the use of polymineral sand sand, which are part of the activated binder as a filler, and which are one of the main components of the enriched aggregate.Conclusion. The optimal formulation of enriched sand was established, with removal of 60% of the fraction 2.5 - 1.25 mm from the crushing screenings and the addition of 40% of the fraction of 0.315 - 0.14 mm of sand sand, which significantly reduces the void content of the aggregate to 38.8% and the water requirement of the aggregate to 6.5%, significantly improving the properties of the repair compositions obtained with their use. It has been proved that the studied sand dunes with a characteristic mineralogical, chemical and particle size distribution are an effective component

HIGH-STRENGTH CONCRETE BASED ON THE USE OF SECONDARY TECHNOGENIC RESOURCES

Objectives. Secondary raw materials comprise a valuable means of offsetting previously realised investment and energy costs; moreover, due to not requiring funds for quarrying and processing of raw materials, their use is typically more cost-effective than the development of primary natural resources. The development of new efficient composites based on secondary resources for high-rise construction is a relevant issue.Methods. The production of high-strength concrete is based on modern technological methods that improve the technical and physical-mechanical properties in the integrated use of technogenic raw materials and effective chemical additives.Results. In this paper, prospects for the use of technogenic raw materials generated by the CHP plant of the city of Grozny in combination with rock crushing waste are described. The natural and technogenic raw material base of the Chechen Republic has been studied and the formulations of ash cements and compositions of high-strength concrete V60 classes for compressive strength with complex use of natural and technogenic raw materials for introduction into the construction of high-rise complexes were obtained.Conclusion. The use of fly ash and Polyplast superplasticiser has a favourable effect on formation processes of the structure and porous space of cement stone with an optimal additive proportion of 1.6%. The complex use of secondary resources made it possible to obtain a waterproof and high-strength composite having significantly better physical and mechanical properties than traditional concrete. The developed formulations of ash binders and concretes based on fine-dispersed ash microspheres and enriched artificial aggregates promoted recycling of secondary raw materials and improvement of the ecological situation in the region

STRUCTURE AND PROPERTIES OF CONNECTING ALKALINE ACTIVATION USING CEMENT DUST

Objectives In the process of firing Portland cement clinker in electrostatic precipitators, in rotary kilns, a large amount of harmful substances, both clinker and aspiration, accumulates, therefore rational use of these products leads to certain shares of a full-fledged river resource, which are derived from industrial cement. It should be noted that the reuse of dust electrostatic precipitators is impossible.Method The basis for obtaining durable and more resource-efficient composites is based on modern technological methods that contribute to the improvement of technical and physicomechanical properties, with the integrated application of technogenic raw materials and liquid sodium binder.Result The basis for obtaining durable and more resource-efficient composites is based on modern technological methods that contribute to the improvement of technical and physicomechanical properties, with the integrated application of technogenic raw materials and liquid sodium binder.Conclusion The developed clinker-free binder formulations using the cement industry wastes and sodium-based sludge glass will make it possible to produce less expensive, durable, and durable composites that will partially replace traditional concrete with expensive portland cement

OBTAINING CLINKERLESS CEMENTS THROUGH THE SYNTHESIS OF BASIC SOLUTIONS OF SODIUM SILICATE FROM SILICA-CONTAINING ROCKS

Objectives The creation of clinkerless cements that do not require high-temperature processing and significant natural resources, at the same time as exhibiting good technical parameters, seems to be an important research task. Cements of alkaline instillation, in which alkaline metals play an active role, are capable of interacting with minerals of aluminosilicate nature forming strong and insoluble compounds.Methods Concrete composites from binding substances activated by alkaline were developed on the basis of Russian and foreign experience of using cinder slag composites in construction.Results In this work, energy-dispersion microanalysis of the developed clinkerless compositions based on alkaline silicate sodium solutions from silica-containing rocks was carried out.Conclusion Formulations of clinkerless cements based on high-dispersal powders of different natures mixed by the alkaline solution obtained using the wet technique at temperatures of up to 95 °C and atmospheric pressure are proposed. This technology will expand the use of alkaline cements, thus leading to the development of concrete having desired properties

THEORETICAL BASIS OF COMPATIBILITY OF COMPLETELY-FILLED MULTICOMPONENT BINDING SYSTEMS

Abstract. Aim. An important direction in contemporary concrete science is aimed at the development of multicomponent systems using mineral powder fillers in a finely dispersed state to create strong and durable building composites. One of the most significant factors affecting the properties of multicomponent systems is the compatibility of its components. Efforts on the part of leading scientific institutes are aimed at replacing expensive and energy-intensive Portland cement with composite concrete products produced using mixed binders. In this context, the development of modern effective composites based on clinkerless alkaline binders becomes an urgent problem. Methods. Studies into the compatibility of multicomponent cementing systems are based on a contemporary technological approach that contributes to the production of strong and durable cement stone, without the use of traditional Portland cement. Results. Electron probe studies and X-ray phase analysis of concrete produced using a clinker-free alkaline activation binder showed that the studied multicomponent system contains a hydro-aluminosilicate zeolite phase of variable composition, as well as indicating the presence of calcite, quartz, albite feldspar, mica, zeolites and potassium feldspar. Conclusion. The results of the studies confirm the compatibility of all components of the multicomponent system comprised of mineral powder, alkaline coater and surfactant. The proposed technological method can be used to produce strong and durable building composites with clinker-free technology avoiding the use of expensive and energy-intensive Portland cement. Acknowledgments. The work was performed as part of research on the implementation of scientific project No. 05.607.21.0320. “Development of technology for new building composites on clinker-free alkaline binders using substandard natural and secondary raw materials” which received support from the federal target program “Research and Development in Priority Directions for the Development of the Russian Science and Technology Complex for 2014-2020.” Unique identifier for the agreement RFMTFI60719X0320