Nanotechnologies in Construction: A Scientific Internet-Journal

11-17

Authors: Suleimenov Zh.T., Sagyndykov A.A., Moldamuratov Zh.N., Bayaliyeva G.M., Alimbayeva Zh.B.

Introduction. One of the promising ways to get high-strength ceramics is the method of semi-dry pressing of the "coarsely dispersed component – finely ground binder" formula. This method suggests using crushed industrial waste as the core, and finely ground nanostructured fusible clay as the binder material. Methods and materials. In the research, bentonite clay of the Darbazinsky deposit of the Turkestan region was used as plastic material, and dense crystallized phosphorus slag which is a waste of phosphorus production was used as a non-plastic coarse material. The study of the prescription factors’ influence on the basic physical and mechanical properties of ceramic wall materials was carried out by the simplex method characterized as lattice planning of experiments. The nanostructure of the phosphorus slag and bentonite clay formula was studied by the electron microscopic analysis method. Results. The binder content in the amount of 25% guarantees the density of the packages, while the sintering effect becomes sufficient and the strength of the samples is 27.1 MPa. If the amount of binder increases from 25% to 40%, the sintering effect continues to grow and the strength of the samples reaches 54.3 MPa. Discussion. The results show that the most active sintering effect and the dense structures forming in coarse-grained formulas with high-calcium phosphorus slag occur at 40–60% binder content. The presence of flux around slag grains in an amount of less than 30% contributes to obtaining less dense samples, with a binder content of 40%, a density increase is observed, which corresponds to the mixed ceramic structures modeling. Conclusion. To get high-strength ceramic bricks, the content of coarsely dispersed components in the form of phosphorus slag with a fraction of less than 1.25 mm should amount to 60–70%, finely ground phosphorus slag should be 5–10%, and bentonite clay is to be 20–30%. Optimum technological indicators are: calcination temperature 1050–1100oC, pressing pressure 20–25 MPa, press powder moisture content 7–8%.

33-42

Authors: Belozerov V.V., Voroshilov I.V., Oleinikov S.N., Belozerov Vl.V.

Introduction. Currently, one can witness a boom of renewable energy in foreign countries: zones with earth, coastal and even offshore wind power plants are emerging, and the roofs of houses, hotels, schools and hospitals are being "dressed" by solar batteries and by panels to generate electricity and water. At the same time, despite the fact that these installations are unreliable and rare sources, many experts and politicians begin to mistakenly consider them as the basic ones. All that poses a scientific and technical problem of determining the place of nature-like technologies in the structure of life support systems of the population. Methods, models and tools. The paper analyzes the engineering systems of multi-apartment residential buildings and individual residential buildings that deliver life support resources (electricity, gas, cold and hot water, etc.). But one should also note that the engineering systems often keep potential fire-energy and environmental harm. To resolve the mentioned problems, some nanotechnologies and Russian patents concerning autonomous electricity, water, heat supply of individual residential buildings on them were proposed. Results and discussion. Modeling has shown that the combination of "Shukhovskaya" and vortex wind turbines with domestic hydraulic panels and solar panels makes it possible to create duplicated and tripled engineering systems of individual residential buildings, which, in terms of quality, reliability and safety parameters, are several orders of magnitude higher than the existing centralized resource supply systems for the residential sector of cities and rural settlements. Conclusion. The proposed approach makes it possible to determine the place of the so-called renewable energy in the structure of the resource supply system for cities and rural settlements, and it remains to assess its effectiveness, which is supposed to be done using the Leontiev-Ford model and the retro-forecasting method.

53-61

Authors: Balykov A.S., Nizina T.A., Kyashkin V.M., Volodin S.V.

Introduction. Active mineral additives that allow controlling the structure formation processes and properties of cement systems are important components of modern modified concretes. Among the numerous types of modifiers for cement composites, the most effective ones include siliceous and aluminosilicate additives containing a significant amount of nanoscale particles, in particular, nanoparticles of silicon dioxides, clays, aluminum oxides and iron oxides. At the same time, common sedimentary rocks, such as diatomites, trepels, opokas, polymineral clays, etc., along with industrial wastes (silica fumes, fly ashes, metallurgical slags) can be promising raw materials for obtaining such modifiers. The purpose of this study was to establish the influence regularities of mineral additives based on sedimentary rocks of various composition and genesis on the technological and physico-mechanical properties of cement systems with the identification of the most effective modifiers. Methods and materials. Siliceous rocks (diatomite and opoka), calcined polymineral clays and carbonate rocks (dolomite and chalk) from several deposits of the Republic of Mordovia were used as mineral additives. The study of the chemical and mineralogical composition of sedimentary rocks was carried out using X-ray spectral fluorescence spectrometry and X-ray powder diffraction methods. In addition to the chemical and mineralogical composition, at the initial stage of the study, the specific surface area of mineral additives and Portland cement was determined on the PSX-12 dispersion analysis device using the Kozeny-Carman method. Prescription and technological efficiency of the applied mineral modifiers was evaluated by their effect on water demand, water-holding capacity, flowability of cement paste and mixed cement binder activity. The physical and mechanical characteristics of cement systems were determined using standardized and well-known authorial methods. Results and discussion. There were established correlation dependences between indicators of water demand, water-holding capacity, flowability of cement systems and specific surface of mineral additives used. In addition, relationship between the activity index of the studied modifiers and the content of silicon dioxide in their composition was revealed. Conclusions. According to the totality of the conducted studies, diatomite, opoka and calcined polymineral clay were identified as the most promising types of mineral additives. The increased effectiveness of these modifiers in cement systems is due to the peculiarities of their chemical and mineralogical composition, in particular, the presence of active silica-containing components (reactive minerals with an amorphized structure) such as opal-cristobalite-tridymite phase in diatomite and opoka as well as products of partial thermal destruction (dehydroxylation) of minerals of kaolinite and illite groups in the calcined polymineral clay.