Vol. 1 Issue 2

Archives Journal Construction Materials and Products Vol. 1 Issue 2

INVESTIGATION OF INFLUENCE OF PLASMOCHEMICAL MODIFICATION ON MACRO- AND MICROSTRUCTURE OF SURFACE LAYER OF AUTOCLAVE WALL MATERIALS

https://doi.org/10.34031/2618-7183-2018-1-2-4-10
Abstract
Studies of the high-temperature effect of a plasma torch on the formation of a multilayer structure of the protective and decorative coating of autoclave wall materials are presented. The tasks of the work included studies: a temperature gradient in a multilayer protective-decorative coating; chemical composition of the fused, intermediate and deep layers of the protective and decorative coating; influence of sodium liquid glass on the formation of macro- and microstructures of protective and decorative coatings under the influence of plasma; processes of thermal diffusion and redistribution of oxides in the fused, intermediate and deep layers.
It was found that when the plasma torch was treated with autoclave wall materials, the surface layer was heated to a depth of 3000 μm, and the maximum surface temperature reached 2000 °C. The pattern of the change in the structure of the fused and intermediate layer is revealed. It is shown that the preliminary impregnation of the surface of silica brick during plasma treatment due to the formation of a low-melting melt eliminates microcracks in its deep layers, and high plasma temperatures promote intensive evaporation of sodium and calcium oxides from the fused layer.
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PLASMOCHEMICAL MODIFICATION OF WALL BUILDING MATERIALS

https://doi.org/10.34031/2618-7183-2018-1-2-11-18
Abstract
The aim of the work is to study the effect of a high-temperature plasma torch on the processes of phase transformations and layer-by-layer modification of the protective and decorative coating on concrete using as a filler a mixture of quartz sand and hollow glass microspheres. The main tasks included: investigation of the processes of evaporation and thermal diffusion of oxides of plasma-coated coatings; study of phase transformations in the melt and its subsequent crystallization in the process of rapid spontaneous cooling of the fused protective and decorative coating; study of the effect of sodium liquid glass on the processes of polymorphic transformations of alumina and the formation of micro-wicks due to the intense diffusion of sodium oxide; study of operational characteristics of protective and decorative coatings. It was established that the initial phases in the protective-decorative coating are α-Al2O3 and CaO∙6Al2O3 (β-Al2O3), and the liquid sodium glass in the coating leads additionally to the formation of Na2O∙11Al2O3. The top layer of the protective and decorative coating is Na–Ca–Al–Si glass with regions of heterogeneities containing an increased content of sodium oxide. The content of aluminum oxide in the protective and decorative coating based on the battle of high-alumina refractory was 95.1 %. The introduction into the coating composition of sodium liquid glass minimizes the processes of dehydration of the binding component and changes the chemical composition of the protective and decorative coating. Reduction of the aluminum oxide content to 83.0 % affects the microhardness indicators. Microhardness of the concrete surface due to the introduction of liquid glass is reduced from 2510 HV to 887 HV.
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INCREASING THE STRENGTH AND FROST RESISTANCE OF CERAMIC PRODUCTS AT USING MELASSES BARDS AS PLASTICIZER

https://doi.org/10.34031/2618-7183-2018-1-2-19-29
Abstract
Ways of production of ceramic materials with use as the plasticizing additive of the sulphitic and alcohol bards (SAB), the calcium citrate filtrate (CCF) which is liquid withdrawal of production of citric acid in the microbiological way are known. However introduction to raw mix of CoB reduces forming humidity and fall of the formed products insufficiently, and an essential lack of FTsK is the low durability of products on compression with a big volume mass of samples.
In work the possibility of use as the plasticizing additive to a clay lot of withdrawal of the spirit industry – melasses bards is investigated. As a part of molasses the remains of amino acids and other organic substances which have the plasticizing effect on clay materials contain. On the example of natural clays of three various fields the plasticizing action melasses bards is proved, and the number of plasticity of the studied clays increases in direct ratio to increase in additive melassny bards in clay raw mix. It is shown that introduction to raw mix melasses bards leads to improvement of appearance of pottery, decrease in jointing, increase in durability for Veselovsky clay for 7%, for the Oryol clay for 67%, for Bessonovskaya – for 23%.
Research of the received ceramic samples on frost resistance according to requirements of GOST bards unlike the products which aren’t containing additive bards showed high frost resistance of products with additive melass. Also lowered decrease in durability and loss of mass of the samples containing additive melassny bards is noted.
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OPTIMIZATION OF RECEPTURAL-TECHNOLOGICAL PARAMETERS OF MANUFACTURE OF CELLULAR CONCRETE MIXTURE

https://doi.org/10.34031/2618-7183-2018-1-2-30-36
Abstract
Aerated concrete at the moment is one of the perspective thermal insulation materials. However, the production of high-quality aerated concrete products is associated with a number of difficulties, primarily related to the features of the manufacturing technology and, in particular, to the formation of its structure during the period of gas evolution and the impact on this process of a large number of factors. The best conditions for the formation of cellular concrete are created when the maximum gas release and the optimum values of the plasticity-viscous characteristics of the aerated concrete mixture are found. Achieving optimal conditions is extremely difficult, which leads to a deterioration in the physico-mechanical characteristics of the final products. One of the ways to solve this problem is to increase the amount of mixing water, however, along with a positive effect (reducing the viscosity of the system), this leads to a decrease in the gas-holding capacity of the mixture. In this connection, the possibility of increasing the production efficiency of the cellular concrete mixture by optimizing the recipe-technological parameters was considered. With the help of the method of mathematical planning, a three-factor experiment was carried out, as the factors of variation were: the duration of the preliminary aging of the mixture, the dosage of the blowing agent and the water-hard ratio, the output parameters were the compressive strength and the average density of the final products. The obtained results made it possible to reveal the regularities of the change in the output parameters from the variable factors and to establish that the preliminary aging of the mixture before the introduction of the gassing agent positively affects the structure and, as a consequence, the physico-mechanical characteristics of the final products.
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COMPOSITE BINDERS FOR FINISHING COMPOSITIONS

https://doi.org/10.34031/2618-7183-2018-1-2-37-44
Abstract
Belgorod region is one of the leading regions in housing construction, especially private households. This is due to the high demand for finishing materials, in particular, dry plaster and putty mixtures, produced main-ly on the basis of gypsum. However, local producers of such products can hardly compete with imported products due to lower prices. The reason for this is the absence in Belgorod Region, as in many other regions of Russia, of gypsum deposits and, as a result, its rather high cost exceeds that of Portland cement. Such a situation makes the actual development of cement-based finishing mixtures, corresponding to gypsum consumer qualities. The main problems of obtaining plaster compositions based on Portland cement is its excessive activity, low water-holding capacity and, as a result, poor workability and adhesion to the base. The classic solution to this problem is the introduction of a fine component (clay or lime) into such a solution, which makes the solution suitable for plastering, but does not allow Portland cement to realize its strength potential, therefore, does not ensure the effectiveness of its use. Giving the cement-sand mortar the desired properties due to polymer modifiers (structuring and thickening) is unjustified due to their high cost and high consumption. In this regard, at this stage of research, the task was to obtain a mineral system based on Portland cement with properties maximally adapted to obtain plaster mixtures, in order to further produce its modification with the above-mentioned additives at their minimum consumption. Composite binders consisting of a clinker part and a mineral additive were chosen as a tool for solving the problem posed. Due to the choice of the ratio of components, their type and dispersion, processing modes, it is possible to vary the properties of the products obtained within considerable limits.
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FEATURES OF THE SELECTION OF THE RATIONAL STRUCTURE OF THE COMPOSITIONAL GIPS BINDER

https://doi.org/10.34031/2618-7183-2018-1-2-45-52
Abstract
The dynamically developing construction in the Russian Federation makes it necessary to expand the range of alternative types of binders and materials based on them. Such a binder is a previously developed compo-site gypsum binder (CGB), used for the production of materials of various functional purposes.
The manufacture and use of CGB-based composites was made possible by studying the Portland cement-gypsum-water system, the stability of which is ensured by introducing an appropriate amount of active mineral additives that reduce the concentration of Ca(OH) 2 in the liquid phase of the hardening system and create the possibility of hardening under certain conditions without dangerous internal stresses. In this paper, we consider the possibility of using composite gypsum binder for fine-milled quartzitic sandstone crushing dropout and concrete scrap crushing dropout as an active mineral additive. Rational compositions of composite gypsum binder are developed and their basic properties are studied. The reasonable choice of the amount of active mineral additive allows optimizing the properties of the composite gypsum binder.
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