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OVERVIEW: GEOPOLYMER BINDERS BASED ON TPP ASH
Authors: D.D. Babaev, V.B. Petropavlovskaya, T.B. Novichenkova, K.S. Petropavlovskii, M.Yu. Zavadko
Abstract: The article considers the possibility of using cement-free binders as a replacement for Portland cement. It is established that the synthesis of geopolymer systems is a promising direction for the creation of a cement-free binder. It is shown that the most common raw materials for geopolymers today are waste from the fuel and energy (TPP ash) and metallurgical (slag) industries. Two types of alkaline compounds are used as an activator of the geopolymerization process: alkali – NaOH and KOH; sodium, potassium or mixed liquid glass. It is noted that the introduction of a highly dispersed aluminosilicate glass phase of hydraulic removal ash contributes to increasing the density of the material, as well as improving the rheological characteristics of raw mixtures.
Keywords: geopolymers, cement-free binders, hydraulic removal ash, slag, strength, water resistance, environmental friendliness.
CONSTRUCTION BIOCOMPOSITES
USING WOODWORKING WASTE.
PART 3 (SELECTION OF BIOLOGICALLY
ACTIVATED SAWDUST CONCRETE COMPOSITIONS)
Authors: V.V. Belov
Abstract: Ways of woodworking waste application, prospects of their use as aggregate for lightweight concrete and other building materials have been studied. Using mathematical models low-energy-intensive compositions of sawdust concrete have been developed. It is noted that it is achieved the reduction of cement consumption up to 30 %, reduction of material intensity of building constructions, energy costs for their production and reduction of production cost of composites on the basis of woodworking waste in comparison with similar materials by 30–35 %. It is indicated that in the process of using woodworking waste as the main raw material an additional energy-saving and ecological effect is formed. It is emphasised that due to the effective use of raw materials it is expected to reduce the cost of production by 18–20 %.
Keywords: woodworking wastes, sawdust concrete, wood aggregate, compositions, properties.
GYPSUM MATERIAL FOR RESTORATION WORKS
BASED ON HIGH-STRENGTH GYPSUM WITH HOLLOW GLASS MICROSPHERES
Authors: A.F. Buryanov, E.V. Tkach, D.V. Stibunov
Abstract: As a result of scientific research it has been established that the joint introduction of hollow glass microspheres (HGMS), hydrophobic-plasticising additive (superplasticiser (SP) Peramin SMF-10 + hydrophobiser (HF) Vinnapas 8031 H) and metakaolin into high-strength gypsum leads to a synergetic effect. The obtained effect is manifested in the intensity of the process of formation of crystalline hydrates of larger sizes, providing compaction and strengthening of the structure of the gypsum stone matrix of reduced average density with improved performance properties of the composite material in terms of compressive and bending strength, water resistance, sorption moisture and water absorption. By means of electron microscopy, X-ray phase analysis and chemical analysis methods the joint influence of PSMS, hydrophobic-plasticising additive (SP + GF) and metakaolin on the process of formation of dense dendrite-like structure of gypsum stone in confined conditions was revealed, which is formed from crossed in different planes regular intergrowths of gypsum crystals, which form a stronger contact zone between microsphere and gypsum stone.
Keywords: high-strength gypsum, hollow glass microspheres, superplasticizer, water repellent, synergistic effect.
CONTRADICTIONS IN THE NORMATIVE DOCUMENTATION
FOR REINFORCED CONCRETE PRODUCTS
Authors: Yu.Yu. Kuryatnikov
Abstract: The article analyses the problems arising in the manufacture of reinforced concrete products and related to the inconsistency of provisions of normative documents. It is noted that when updating outdated normative documentation, adoption of new documents by different institutes inconsistency, duplication and vagueness in requirements are allowed. The ways of solving these problems are proposed.
Keywords: reinforced concrete products, regulatory documentation, reinforcement schemes, culverts, well rings, road slabs, reinforcing steel, composite reinforcement.
ON THE ISSUE OF TECHNICAL REGULATION
OF THE CONSTRUCTION OF BUILDINGS FROM CLT-PANELS
Authors: Yu.N. Moskvina
Abstract: The article gives an overview of measures to promote the use of CLT-panels, as well as the legislative and regulatory framework in the field of technical regulation of wooden house building. The advantages of the construction material are highlighted.
Keywords: construction, wooden house construction, CLT-panels, technical regulation, research activities.
MATHEMATICAL EVIDENCE OF THE LAWS
OF QUANTUM THERMAL RADIATION OF GAS VOLUMES.
PART II. LAWS OF QUANTUM THERMAL RADIATION
OF SPHERICAL GAS VOLUMES
Authors: A.N. Makarov
Abstract: The mathematical description of the derivation of the second-fifth laws of thermal quantum radiation of spherical gas volumes is given. It is noted that by spherical gas volumes of different sizes (up to spheres of atoms) it is possible to model thermal quantum radiation of gas volumes of any sizes and shapes by inscribing spheres of different diameters (up to nanospheres with atom size) into gas volumes.
Keywords: quantum, laws, thermal radiation, gas volumes, torch, electric arc, furnace, furnace, combustion chamber.
ELECTRIC VEHICLES: PROBLEMS, TRENDS
AND DESIGN OF CHARGING STATIONS
Authors: Yu.M. Pavlova, O.N. Torgovanova, A.V. Pavlov
Abstract: The paper discusses the current trends and challenges in the development of "smart electric vehicles" based on new electric and plug-in hybrid electric vehicles. It is noted that the current electrical grid is unable to handle the increased demand for electricity needed for the large number of charging stations, especially during peak times. It is also indicated that the envisioned critical infrastructure for such vehicles should include the ability to share information regarding energy availability, distances, congestion levels, etc. Topics related to control, demand response, infrastructure provisioning and communication infrastructure required to realise the above functions are explored.
Keywords: electric vehicle, plug-in hybrid electric vehicle, smart grid, smart grid, charging station, fast charging, electric grid, power grid, smart grid.
THEOREM ON THE CENTER OF n-SYMMETRY OF A FLAT CONVEX PLATE
Authors: Al.A. Shum, A.M. Vetoshkin
Abstract: The concept of the center of n-symmetry of a flat plate is considered. Special cases of n-symmetry are s-symmetry and c-symmetry (respectively 0-symmetry and 1-symmetry). The following theorem is proved: in any convex area of the plane, it is possible to determine the density function so that the center of the n-symmetry of the resulting plate will be located at any predetermined internal point of this plate. It is noted that special cases of this theorem corresponding to the values n = 0 and n = 1 were previously known.
Keywords: symmetry, c-symmetry, s-symmetry, n-symmetry, center of symmetry, convex plate, density function, mass, center of mass, electric machine.
ON THE USE OF POLYURETHANE SINGLE-COMPONENT ADHESIVE FOAM
IN THE MANUFACTURE OF AERATED CONCRETE JUMPERS
Authors: A.V. Levikov, A.V. Gavrilenko
Abstract: The article presents the results of experimental bending test of a lintel made of aerated concrete blocks, which is made using only polyurethane foam adhesive foam for masonry without the use of reinforcement, additional metal rolled profiles and classical masonry mortars. Examination of the destroyed specimens revealed sufficient adhesion of the adhesive foam to the aerated concrete under load. It is noted that the aerated concrete glued lintel is able to withstand a distributed load up to 100 kg/m, but the nature of the failure is brittle, which does not allow recommending the use of such lintels in practice. Comprehensive proposals for improving the design of glue-foam bonded blanks, which can prevent brittle fracture character in the process of additional theoretical and experimental studies, are given.
Keywords: polyurethane adhesive foam, aerated concrete blocks, lintel.
UTILIZATION OF INDUSTRIAL WASTE
AS A FACTOR IN PREVENTING THE OCCURRENCE
OF ENVIRONMENTAL HAZARDS
Authors: О.P. Filippova, S.Z. Kalaeva, E.S. Tskhovrebov, Е.S. Sergeev
Abstract: This article presents the results of studies of the composition and properties of common waste of the Yaroslavl region – galvanic sludge and waste «green oil». Based on the data obtained, the technologies for the disposal of these wastes developed on the basis of the Yaroslavl State Technical University are presented. It was noted that the introduction of the proposed technologies will be an important factor in reducing the level of environmental hazards and preventing man-made emergencies in the region.
Keywords: galvanic sludge, «green oil», corrosion, petroleum products, recycling, waste, environmental safety.