Elistratkin M.Yu.

Candidate of Engineering Sciences (Ph.D.), LLC «Issledovatel», Russia

FOR THE STUDY OF PECULIARITIES OF STRUCTURE FORMATION OF COMPOSITE BINDERS FOR NON-AUTOCLAVED AERATED CONCRETE

https://doi.org/10.34031/2618-7183-2019-2-3-41-47
Abstract
The basis of the modern market of cellular concrete is autoclaved gas silicate. At the same time, non-autoclaved aerated concrete is largely a more technological material, allowing the variation of its properties within a wide range, having a potentially wider field of application, less costly in the organization of production, which is of great importance for small and medium-sized businesses. The main problem of non-autoclaved aerated concrete is a higher cost of raw materials compared to silicate, and 20...30% lower strength performance. The proposed solution to this problem is the development of special composite binders with a limited content of clinker and mineral additives of various genetic types, taking into account the peculiarities of the two-stage structure formation of the material – gas porization and the formation of the microstructure of the stone. The article deals with some aspects of the interaction in the system “mineral additive – gypsum – by-products of the gas release reaction” in terms of the effect on the viscosity of the swelling mass and the strength of the stone at different times of hardening. Recommendations are given on the preferred compositions of composite binders and dosages of gypsum in the molding mixture when producing a material with an average density in the range of 500...700 kg/m3.
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COMPOSITE BINDING MINERAL ADDITIVE INFLUENCE ON THE PLASTICIZER EFFICIENCY

https://doi.org/10.34031/2618-7183-2019-2-2-10-16
Abstract
Replacing portland cement with composite binders in many construction spheres is becoming increasingly reasonable. A prerequisite for this is the ability to provide the binder with set of properties necessary for the most effective implementation of a particular practical task at minimum expense. Such optimization allows in some cases to achieve higher performance than the original cement, in others – to form new properties of the material, as well as provide direct or indirect savings of various resources. One of the most important parameters determining the strength characteristics of composites and their durability is the used binder water requirement. Furthermore in some cases the mixture must have certain rheological characteristics. Various types and generations plasticizing and water reducing additives are widely used to regulate these parameters. The article discusses relation of fine components electrosurface properties – the clinker component and various genetic types mineral additives for the main types of plasticizers magnitude diluting effect. The basic mechanisms and regularities are described, recommendations that allow to optimize the consumption of expensive additives or increasing their effectiveness in solving various practical problems are formulated.
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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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ANALYSIS OF THE FACTORS OF INCREASING THE STRENGTH OF THE NON-AUTOCLAVE AERATED CONCRETE

https://doi.org/10.34031/2618-7183-2018-1-1-59-68
Abstract
Non-autoclaved aerated concrete is the only real alternative to gas silicate in the organization of its release on the basis of regional production of small and medium capacity. This will help improve the competitive environment in the building materials market and optimize the cost of construction. Of particular interest is the possibility of expanding the field of application of this material due to a significant increase in strength characteristics, while maintaining its average density in acceptable, in terms of thermal insulation properties, limits - not more than 1000 ... 1100 kg/m3. At a strength level of 10 MPa and above, in combination with dispersed reinforcement or the use of traditional non-metallic reinforcing elements, such aerated concrete can be used as a lightweight structural material for creating power elements of low-rise buildings, including in promising construction printing technologies; devices distributing the load belts; non-removable formwork; porous, stiffening, filling thin-walled tubular structures. The paper presents an assessment of the effectiveness of traditional ways to increase the strength of non-autoclaved aerated concrete. New solutions for the purposeful formation of the pore space structure are proposed and tested due to the creation and use of a gas generator with normalized gas evolution, which allows the creation of pores of a given volume. The key to the economic effectiveness of the proposed solutions is the transition from traditional portland cement to composite binders based on it. The substantiated choice of the amount and composition of the mineral additive makes it possible to optimize the properties of the binder under the particularity of the problem being solved, and to minimize the consumption of cement and chemical modifiers, increase the speed of durability and the final indices of non-autoclaved aerated concrete.
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