Valery Bratchun, Valentin Demeshkin, Olga Narizhnaya,
Mikhail Rodzin, Alexander Krasnoperov, Maxim Solovyov, Petr Deineka
Optimal Temperature and Time Modes of Production of Tar-oil Polymer Binders Modified by Primary Waste from the Production of Thermoplastics
Donbas National Academy of Civil Engineering and Architecture
Abstract. Microscopic, conductometric, and viscometric methods have shown that when combining primary powdered waste from the production of polyvinyl chloride (screenings, filter cake, crust, dust) and polystyrene (screenings), there are several characteristic temperatures: the swelling temperature (50…70 °C), corresponding to the transition of the polymer from glassy to highly elastic state; the temperature of dispersion of polymer particles on aggregate-globular formations as a result of the swelling pressure of the y-fraction of coal binders sorbed by polymer particles; dissolution temperature (105…125 °C). The optimal preparation time for tar-oil polymer binders (TOPB) at dissolution temperatures is 50–70 minutes. Under these temperature-time conditions for the production of TOPB, the maximum adhesion of the tar-polymer binder to the surface of mineral materials and the elasticity of the modified organic binder are achieved.
Key words: tar-oil polymer binders, primary waste from the production of polyvinyl chloride and polystyrene, temperature-time regimes for the production of tar-oil polymer binders.
Alexander Sazanov a, Alexander Tsaruk b, Sergey Trigub b, Aleksey Chikun b
About the use of use of By-Products of the Industry as a Mineral Powder of Road Asphalt Concrete
a SEI HE LPR «Lugansk State University named after Vladimir Dahl», b Donbas National Academy of Civil Engineering and Architecture
Abstract. An analysis of the literature data indicates that many powdered by-products of industry are used as a mineral powder: fly ash from thermal power plants, dolomite dust, fly ash from cement kilns, decomposed slag particles, acidic silica waste from industry, sulfur-containing waste, etc. Nevertheless, these powder products inferior in quality to limestone mineral powder. Many increase the consumption of organic binder, have insufficient adhesion to the binder, a small specific surface or, conversely, a highly developed inner surface, intensify the aging process of concrete and thereby reduce the durability of non-rigid road surfaces. In this regard, we consider it expedient in further research to consider existing methods for improving the quality of mineral powders and, above all, changing their surface properties in order to increase their density and enhance the structuring ability in concretes based on organic binders.
Key words: road asphalt concrete, mineral powder, technogenic raw materials for the production of mineral powder of asphalt concrete mixtures.
Igor Shilin, Arkadii Khimchenko, Yulia Sokolova
Development of a Model of the Outline of a Repair Map on a Road Surface After Cold Milling
Automobile and Road Institute SEI HPE «Donetsk National Technical University», Gorlovka
Abstract. The analysis of the applied methodology for the preparation of damaged sections of road surfaces in the process of their restoration during the current (patching) repair is carried out. The generalized issues of simulation modeling of the process of cold milling of non-rigid pavement are considered and an algorithm for creating a simulation model is presented. The initial data and accepted limitations in the modeling process are described, on which the purity of milling of the deformed coating surface depends. The use of the model in conjunction with other mathematical methods allows, based on the accepted criteria, to obtain the shape of the outline of the surface of the milled repair card and the volume of the repair mixture required to fill it. This technique is generalized and will be improved from the point of view of taking into account the specific designs of the working bodies of road cutters and the technological parameters of cold milling, the main differences in the methodology for determining the need for road-building materials depending on the purity of milling, with the accepted intervals of variation of established factors, are formulated. The main differences in the methodology for determining the need for road-building materials, depending on the purity of milling, with the accepted intervals of variation of the established factors, are formulated. The main directions of further research are established on the basis of the obtained results of simulation modeling.
Key words: road milling cutter, routing, road surface, cutter.
Valery Bratchun, Denis Gulyak, Vyacheslav Zhevanov, Nikita Leonov, Dmitriy Skorik
Deformation-Strength Characteristics of Complex-Modified Tar Concrete
Donbas National Academy of Civil Engineering and Architecture
Abstract. It has been experimentally established that tar concrete prepared using complex coal binders is more durable under the action of transport loads than standard tar concrete. This is evidenced by: a variety between residual porosity and water saturation, which shows the volume of closed pores in mixtures on complex coal binders (CCB) by 20…30 % more than for combustible tar concrete; higher values of critical stresses of tar polymer concrete; higher values of the modulus of elasticity at elevated temperatures (40…50 °C); the interval of viscoelastic behavior is much wider for tar-polymer concretes in comparison with traditional tar- concretes and warm asphalt concretes; the physical and mechanical properties of tar polymer concrete and heavy asphalt concrete are identical, which determines the scope of their application. It has been established that there is a correlation between the conditional glass transition temperature of concrete using complex coal binders and the glass transition temperature of organic binders. This indicates that the properties of complex-modified binders determine the rheological behavior of tar-polymer concrete. It has been established that the power-law dependence of the elastic modulus on the frequency of deformation, expressed in terms of the coefficient of plasticity on temperature, has an extreme character. The reason for this is the relaxation processes that occur most intensively in asphalt concrete, as evidenced by its higher values of the coefficient of plasticity at low temperatures than concrete with the use of CCA and hot tar concrete.
Key words: complex-modified road tar polymer concrete, deformation-strength properties and durability of tar polymer concrete.
Valentina Kibzun, Nina Nagornaya
Theoretical Aspects of the Formation of the Assortment and Quality of Leather Goods on the Market of Donetsk
State Organization of Higher Professional Education «Mikhail Tugan-Baranovsky Donetsk National University of Economics and Trade»
Abstract. The purpose of the article is to study the factors of the formation of the assortment and quality of leather goods in the regional markets of Donetsk. The scientific novelty consists in the development of ways to modify the assortment policy of the enterprise on the basis of consumer evaluation, structured analysis of experimental data, determination of optimal indicators of consumer properties of leather haberdashery, as well as improvement of the methodology for their assessment of quality and competitiveness. The factors forming the assortment of leather goods are specified, their influence on the formation of the assortment of the enterprise is shown, and in general, an analysis of the local market and suppliers of leather goods is made on the actual material. It is established that the research methods used in the work can be applied in the examination of the quality of leather goods, which will undoubtedly increase the efficiency of work.
Key words: commodity market, competitiveness, consumer properties, demand, expertise, leather haberdashery.
Maxim Voronenko, Anastasia Skibina, Elena Yegorova, Sergey Lakhtaryina,
Irina Petrik
Heavy Concrete for Hydraulic Structures
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article provides a theoretical and experimental justification of the feasibility of using pozzolan cements and chemical additives in heavy concrete. To obtain the most dense and durable concrete, the selection of the mass ratio of large and small aggregates was carried out. As a result of experimental studies, it was found that when using a large aggregate of fractions 5…10/10…20 mm, their optimal number and ratio is 30/70 % and 70/30 %. It is advisable to fill the residual intergranular space with a fine aggregate with its content of 43 % of the total mass of all aggregates. In particular, the use in the composition of concrete mixtures of fly ash from Zuevskaya TPP in the amount of 30 % instead of cement in the combined binder and superplasticizer P7 of the «Green Thermo» trademark makes it possible to obtain concretes with improved characteristics when using fine aggregate that does not meet the requirements of regulatory documents.
Key words: hydraulic concrete, concrete composition, fly ash, superplasticizer, voidness, mobility, strength.
Yuriy Kochergіn, Viktoriya Zolotareva
Relaxation Properties of Composite Materials Based on Epoxy-Rubber Mixtures Cured with Cardo-Polyarilate
State Organization of Higher Professional Education «Mikhail Tugan-Baranovsky Donetsk National University of Economics and Trade»
Abstract. The kinetics of curing of ED-20 epoxy resin with polyarylate and the product of its preliminary esterification reaction with SCN-30 butadiene acrylonitrile carboxylate rubber was investigated by dynamic mechanical analysis. Polyester terephthalic acid and phenolphthalein were used as polyarylate. On the basis of temperature dependences of the tangent of the angle of mechanical losses and the dynamic shear modulus, the boundaries of the curing reaction interval due to the interaction of epoxy cycles with the ester group are determined, primary information on the properties of the resulting product is obtained. Electron microscopy has shown that the curing of epoxy-rubber compositions with polyarilate leads to the formation of microheterophase structures. Due to the significant difference in the values of the solubility parameters of polyarylate and rubber, micro-stratification of the system occurs with the release of rubber into particles of an independent phase. The coupling between the rubber phase and the polyarylate is carried out by the resin portion of the product of the preliminary esterification reaction, which due to the thermodynamic affinity mixes well with the polyheteroarylene, forming an interfacial layer. Subsequent heating of the compositions at 453 K, resulting in chemical interaction with polyarylate, further enhances this adhesion, which is reflected in a higher value of the dynamic shear modulus in a wide temperature range from 293 to 550 K. The presence of a rubber component in the composition leads to greater creep of the material under mechanical load.
Key words: epoxy resin, butadiene acrylonitrile carboxylate rubber, polyarylate, dynamic shear modulus, tangent of the angle of mechanical losses, creep.
Yuriy Kochergіn, Viktoriya Zolotareva
Properties of Composites Based on Epoxy Resin Modified with Organic Tin Halide
State Organization of Higher Professional Education «Mikhail Tugan-Baranovsky Donetsk National University of Economics and Trade»
Abstract. A modified resin based on organic tin halide, which is used as dibromide dibutyltin, and industrial epoxy resin of the ED-16 brand was synthesized. A comparative study of the complex of physical-mechanical and relaxation properties of composites based on the initial and modified resins cured at room temperature and subjected to heat treatment is carried out. It was found that composite materials based on modified resin are characterized by lower values of tensile strength, elastic modulus, tensile strength and glass transition temperature compared to samples based on the original epoxy resin. The values of strain at break are approximately the same for both resins. The observed change in the deformation and strength properties of samples during their exposure in a liquid medium is explained by the superposition of the effects of plasticization and re-hardening of epoxy polymers. At short exposure times, the action of the sorbed liquid is mainly aimed at weakening the intermolecular interaction in the sample, which reduces its tensile strength and increases its deformation capacity. At long exposure times, when the amount of absorbed liquid becomes sufficiently large and intense molecular movement occurs, pre-hardening processes prevail, leading to an increase in the cross-linking density and, as a result, to a decrease in the deformation ability and an increase in the strength index. It is shown that composites containing epoxy resin modified with dibromide dibutyltin are characterized by increased resistance to the development of fungi and mold, as well as better fire resistance. The studied polymers can be considered as promising for obtaining antifouling coatings based on them for hydraulic equipment, sea and river vessels.
Key words: epoxy composite, organic tin halide, deformation-strength and relaxation properties, fire resistance, antifouling fungus-resistant coatings.
Vitaly Bespalov, Artur Markov, Anatoly Yukhnov, Vladislav Sirenko,
Rodion Maidanichenko
Complex Organic Binder Based Visco-Plastic Secondary Vat Residues Phenol-Acetone Production
Donbas National Academy of Civil Engineering and Architecture
Abstract. The purpose of this work is to obtain from VKOFAP (secondary VAT residue of phenol-acetone production) an organic binder that meets regulatory requirements. VCOFAP was modified with a complex additive represented by polyvinyl chloride screening and distillation residues of phthalic anhydride distillation. Secondary viscoplastic HCOFAP is formed from primary HCOFAP during the joint production of phenol and acetone by the cumene synthesis method and contains up to 50 % of resinous and condensation products, dimers and volatile components: a-methylstyrene, phenol, acetophenone. The indicators of physical and mechanical properties of concrete prepared on a complex organic binder exceed those of hot tar concrete. They are characterized by higher compressive strength at 50 °C and a wider temperature range of performance in the viscoelastic state; lower temperature sensitivity of mechanical properties. Consequently, coatings built from concrete mixes based on a complex organic binder will be durable under the action of transport loads.
Key words: road asphalt concrete, viscoplastic secondary cubic residue of phenolic-acetone production, polyvinyl chloride, cubic residues of distillation of phthalic anhydride.
Vitaliy Yurchenko a, Anastasia Коt b, Natalia Kurochkina b, Ekaterina Petrushina b
Optimization of the Fractional Composition of Composite Building Material Made of Recycled High-Pressure Polyethylene and Fine Wood Processing Waste
a State Educational Institution of Higher Vocational Education «Donetsk Railway Transport Institute», b Donbas National Academy of Civil Engineering and Architecture
Abstract. Optimization of the fractional composition of a composite building material based on high-pressure polyethylene grade 15803-020 and fine-dispersed wood processing waste with a fraction of 0,33…5,00 mm has been carried out. The optimal fractional composition of a composite building material made of recycled high-pressure polyethylene and fine wood processing waste has been determined. The distribution of wood filler by weight and size showed that the largest fraction has a fraction of 0,63…1,25 mm – 49,9 %. The optimal fractional composition of particles of secondary high-pressure polyethylene is provided with a fraction of less than 0,63 mm. Optimal concentrations of components in the product have been experimentally established, which varies in the following range: wood filler 69…71 % by weight, secondary high-pressure polyethylene 26…28 % by weight, modifying additives
3 % by weight (wax – 2,5 % by weight, LLDPE Coupling agent 04688 super concentrate –
0,3 % by weight, flame retardants – 0,2 % by weight).
Key words: secondary high-pressure polyethylene, fine wood filler, fractional composition, composite polymer material.
Alana Satkoeva
Methods for Increasing the Durability of Road Crushed Stone-Mastic Asphalt Concrete by Complex Modification of the Structure of Crushed Stone-Mastic Asphalt Concrete
SAEI HPE «South Ossetian State University named after A. A. Tibilov»
Abstract. The compositions and technologies of production, laying and compaction of crushed stone-mastic asphalt concrete mixtures are considered. It is shown that an effective way to improve the quality and durability of crushed stone-mastic asphalt concrete mixtures is the complex modification of the organic binder with a complex additive consisting of butadiene-methylstyrene rubber and technical sulfur, as well as finishing the surface of mineral materials of crushed stone-mastic asphalt concrete with Butonal NS198 divinyl-styrene rubber latex. Theoretical and methodological provisions for the formation of the structure of a complex-modified crushed stone-mastic asphalt concrete mixture, characterized by a wide temperature range of compactibility, are formulated. This is achieved with an optimal quantitative ratio between micro-, meso- and macrostructures, namely, when designing durable SMA, it is necessary to create a stable frame, deformation-relaxing asphalt-polymer binder with high adhesive-cohesive properties, and the volume of residual pores in SMA should be minimal.
Key words: complex-modified crushed-stone-mastic asphalt concrete, composition, structure, properties.
Victor Levchenko, Vladimir Krotiuk, Sergei Vodolazskii, Daria Ovcharenko,
Vera Khomich
Economic Justification of Reliability and Durability of Engineering Structures of Buildings and Constructions
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article deals with the issues of reliability of buildings and structures, as well as its formation at all stages of the existence of buildings and structures. Assessment of the technical condition of buildings and structures is intended for the qualitative and quantitative presentation of indicators characterizing the properties of materials and the condition of objects, for studying the processes taking place in structures, foundations and equipment, as well as for identifying the actual performance properties of materials, structural elements and establishing their compliance with technical requirements. Ensuring the required level of reliability of buildings and structures in the process of their existence is carried out by technical and organizational methods. The general issues and the current state of this problem, including the main provisions of the design of the durability of reinforced concrete structures, existing methods, the economic justification for its assessment, concepts and criteria related to durability.
Key words: reliability, durability, redundancy, defects, maintainability.
Pavel Yavtukhovsky, Aleksandr Kudinov, Nikita Kudinov, Denis Gulyak
The Use of Asphalt Heating Complex for the Repair of Road Pavement
Donbas National Academy of Civil Engineering and Architecture
Abstract. The effective use of vehicles is possible only under the condition of high-quality maintenance and repair of highways. In modern conditions characterized by a significant amount of work on the maintenance and repair of highways, the issues of intensification of these works by the introduction of modern technological processes for equipping operating organizations with high-performance, reliable equipment are of great importance. The work of machines created in recent years for the restoration of asphalt concrete is based on its ability to acquire plastic properties during flameless heating without changing its physical and mechanical properties. The emergence of new machines for the destruction, heating and restoration of asphalt concrete, as well as its industrial regeneration, made it possible to propose and use a large number of new technological processes for the repair of asphalt concrete pavements, which are based on the possibility of heating and bringing asphalt concrete to a workable state.
Key words: pavement repair, heating of asphalt concrete, asphalt heating complex.
Aleksandr Stukalov, Aleksandr Bugaets, Vladislav Shablya
Features of Technological Aging of Oil Road Bitumen in the Composition of Asphalt Binder
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article presents data indicating that the preparation of an asphalt binder by mixing mineral powder with petroleum road bitumen fundamentally changes the process of thermal oxidative aging of bitumen in thin films (less than 160 microns). Bitumen in the «free film» undergoes thermooxidative diffusion of air oxygen to the entire depth of the organic binder film, and bitumen films on the surface of the mineral material undergo thermooxidative aging largely due to the air oxygen involved when mixing the components of the asphalt concrete mixture. To minimize technological aging processes, it is necessary to prevent air diffusion into bitumen and into the asphalt mixer, and in order to increase resistance to thermal-oxidative aging, it is advisable to modify petroleum road bitumen with polymers, in particular, styrene-butadiene-styrene rubber.
Key words: viscous road bitumen, technological aging, thermo-oxidative aging, weight loss, mineral powder, asphalt binder.
Elina Radyukova, Vladislav Goryainov
Butonal NS 198 Latex-Modified Asphalt-Polymer Road Concretes of Increased Durability
Donbas National Academy of Construction and Architecture
Abstract. The work is devoted to the development of compositions of road modified asphalt concrete of increased durability with a complex modified structure with cationic latex Butonal NS 198. It has been experimentally established that for fine-grained asphalt concrete of type «В» containing BND 40/60 bitumen modified with 3 % cationic latex Butonal NS 198, the optimal concentration of Butonal NS 198 on the surface of mineral materials: crushed stone, sand, mineral powder is 2.0 % by weight. Asphalt concrete mixtures complexly modified with NS 198 Bud compared with mixtures with modified NS 198 organic binder Bud are characterized by an increase in density up to 2 348 kg/m3, compressive strength at 20 °C – up to 5.5 MPa, at 50 °C – up to 1.94 MPa, as well as a decrease in water saturation up to 2.03 % of volume.
Key words: bitumen, modification, cationic latex Butonal NS 198, asphalt concrete with complex-modified micro-, meso- and macrostructure.
Valeriy Bratchun, Oleg Pshenichnykh, Evgeniy Romasyuk,
Pavel Ponomarenko, Taisiya Vasilyeva, Denis Koval, Stanislav Prisyazhnyuk,
Igor Kaminsky
On the Formation of the Structure of Adsorption-Solvate Layers of Asphalt Chrysotile Binder on the Surface of Mineral Materials of Road Asphalt Concrete
Donbas National Academy of Civil Engineering and Architecture
Abstract. This article discusses the theoretical issues of the formation of the structure of adsorption-solvation layers of asphalt-chrysotile binder on the surface of mineral materials of road asphalt concrete. Interaction of dispersed fibrils of chrysotile reinforcement with mineral components of asphalt concrete mixture in the adsorption layer is considered. It has been established that the diameter of dispersed reinforcement plays a key role in the formation of homogeneous and durable adsorption-solvation layers of organic binder in reinforced asphalt concrete. It is shown how the interaction between the particles of the mineral part and the formation of bonds between the near and far series of contacts is carried out. The influence of the content of one percent of chrysotile asbestos in asphalt concrete on such indicators as: shear strength, tensile strength in bending at negative temperatures, fatigue life, corrosion resistance is analyzed.
Key words: asphalt-chrysotile binder, asphalt concrete, chrysotile-asbestos, dispersed fibers, adsorption layer, mineral material.
Konstantin Guba b, Andrey Velichko a, Andrey Panasenko a, Alexander Kosik a
Modification of Asphalt Granulate Bitumen
a Donbas National Academy of Civil Engineering and Architecture, b Automobile and Road Institute «Donetsk National Technical University»
Abstract. Currently, financing of the road industry in the territory of the Donetsk People’s Republic is carried out in incomplete volume for a number of reasons independent of the road industry itself. Therefore, the question arises of finding new, more economical materials for the production of asphalt-concrete mixes to perform repairs and technological operations that allow you to perform these works. The possibility of using materials obtained by milling old asphalt concrete in the repair of non-rigid road surface, which is formed in large quantities, is considered. The use of regenerated asphalt concrete will reduce the cost of new expensive mineral materials (crushed stone, sand, mineral powder) and organic binder. When performing repairs, the old asphalt concrete is removed, which can be used as an independent material, or as a component of the newly prepared asphalt concrete mixture. The regenerated asphalt mix requires a slight improvement in the physical and mechanical properties of bitumen found in old asphalt concrete.
Key words: old asphalt concrete, regeneration of asphalt concrete surfaces, asphalt granulate, bitumen, modification, modifying additives.
Helen Samojlova, Natalya Shkurko, Alina Byvalina, Victoria Buts
Ensuring Environmental Compatibility in the Design of the Road Surface
Donbas National Academy of Civil Engineering and Architecture
Abstract. It takes a lot of effort to restore the pavement: first, the outdated pavement should be eliminated and taken out for reuse, and then a new one should be laid. It is not so easy to increase the load-carrying capacity of the route: it is impossible to remove all the layers laid earlier to replace them with new ones. However, if you use the material of the old coating on the roadbed itself, then these two tasks will be much easier. The article suggests the use of «cold» recycling technology as a modern method of recycling and regeneration of old pavement for repair facilities of the Donetsk People’s Republic – the technology of shallow or shallow recycling of coating layers (up to 10 cm), as well as the calculation of costs and the cost of repairs using the technology of small «cold» recycling. The results of measurements of physical and mechanical parameters of samples of regenerated organo-mineral mixture on the highway T-05-09 Velikaya Novoselovka – Amvrosievka, km 119+000 – km 133+909 are presented.
Key words: recycling, regeneration, road clothes, organo-mineral mixture, polymer additive, environmental friendliness.
Svetlana Frolova, Oksana Sobol, Aleksandr Sobolev
Analysis of Thermal Hysteresis Phenomena During Melting and Crystallization Na2S2O3*5H2O
Donbas National Academy of Civil Engineering and Architecture
Abstract. The processes of melting and crystallization underlie the creation of phase-transitive heat-accumulating materials (PTHAM). Since hysteresis phenomena are undesirable for PTHAM, it is quite an urgent task to clarify the mechanisms of direct and reverse phase transformations, their interrelation with each other, to identify the reasons for the difference between nonequilibrium crystallization and equilibrium, the study of thermal hysteresis is quite an urgent task. In this work, various thermal hysteresis processes were analyzed based on the analysis of heat and cooling thermograms Na2S2O3*5H2O. Three types of thermal hysteresis were identified: the first type (TG-I) – when comparing the equilibrium melting process with the non-equilibrium crystallization process; of the second type (TG-II) – when comparing equilibrium melting and crystallization processes with different melting and crystallization temperatures, as well as combined (KG), combining TG-I and TG-II. Schemes for changing enthalpy and Gibbs energies in various types of hysteresis phenomena have been developed. According to the above enthalpy change schemes, it is possible to predict values of the thermal hysteresis value, which is desirable for the creation of phase transition heat storage materials.
Key words: melting, crystallization, sodium thiosulfate pentahydrate, heat storage material, thermal hysteresis.
Alexander Barmotin
Design Features of Facades of Civil Buildings
Donetsk Design and Survey Institute of Railway Transport «DONZHELDORPROEKT»
Abstract. Exterior decoration of facades of buildings performs not only decorative and aesthetic functions, but also protects the enclosing wall structures from adverse external influences such as increased humidity of the outdoor air, overheating from exposure to ultraviolet radiation, penetration of mold, fungus, etc. into the load-bearing walls. With the use of modern technologies and materials for finishing facades, it is possible to perform additional wall insulation. External insulation helps to maintain a favorable microclimate inside the premises, eliminating excess moisture, the formation of fungus and freezing of the enclosing structures. In this regard, an analysis and classification of factors influencing the choice of technology for the device and repair of building facades has been carried out. The design and technological features of the most common facade systems, namely, systems of hinged ventilated facades and systems with plaster coatings with a heat-insulating layer, have been identified.
Key words: enclosing structures, factors, facade systems, hinged ventilated facade, plaster facade, design and technological features.
Olga Shevchenko, Svetlana Sokhina
Method for Predicting the Durability of Protective Coatings Based on Recycled Waste from the Chemical Industry According to Art. 3
Donbas National Academy of Civil Engineering and Architecture
Abstract. It has been proposed a method for calculating the failure time of a protective coating for metal using a full factorial experiment, determining a function that optimally describes the generalized indicator of the quality of a protective coating (Az) in time, and identifying the lifetime of the coating on this basis. The resulting mathematical models describe with a sufficient degree of accuracy the change in the protective properties of coatings over time and make it possible to predict their lifetime. At the same time, the correlation coefficient for modified compositions based on indene-coumarone resins varies within the limits of: R = 0.979…0.999; so = 0.02…0.03; for compositions based on cubic residues of the production of synthetic fatty acids of the C-20 fraction and higher, the correlation becomes significant according to the Fisher criterion for a test period of more than 29 days: F = 3.74 – 85: R = 0.83…0.94; so = 0.03…0.05.
Key words: prediction of coating lifetime, corrosion damage, reliability, durability, calculation-theoretical method, models of corrosion elements, industrial waste disposal, anti-corrosion protective coatings, accelerated tests.
Victoriia Mazur, Bogdan Chekal
Factors Influencing the Choice of Organizational and Technological Solutions for the Overhaul of Metal Cooling Tower Cladding
Donbas National Academy of Civil Engineering and Architecture
Abstract. The factors influencing the choice of organizational and technological solutions for the overhaul of the cladding of cooling towers with a metal frame are considered in this article. The need for major repairs of the cladding of metal cooling towers arises after the first five years of their operation, since the structures are operated in aggressive conditions. The specificity of the design solution of the cladding located inside the towers of cooling towers complicate the repair work. Many other factors related to operating conditions, atmospheric influences, conditions of tightness of the construction site, material consumption and cost of technology, etc. also affect the choice of technology and the organization of the processes of capital repairs of metal cooling towers. The complex classification of factors makes it possible to further model the main technical and economic indicators of work performance (labor intensity, cost, duration of work, the period of further maintenance-free operation of the cladding), taking into account the mutual influence of individual groups of factors in specific operating conditions.
Key words: major repairs, cladding, metal cooling towers, classification of factors, organizational and technological solutions.
Vitaly Bespalov, Sergey Goshko, Yulia Goshko, Alexey Grishko
Determination of the Effective Working Time of Concretes Prepared on Modified Secondary Cubic Residues Phenolic-Acetone Production
Donbas National Academy of Civil Engineering and Architecture
Abstract. The paper studies the patterns of change in the modulus of elasticity of concrete and related characteristics prepared using modified secondary bottoms of phenol-acetone production under conditions close to operational. Frequency dependence of the complex modulus of elasticity E* of fine-grained concrete on a complex organic binder (viscous-plastic VKOFAP, modified with 1.5 wt. % polyvinyl chloride screenings (OPVC) and 30 % phthalic anhydride distillation residue (PDPA)) at temperatures: 1 – (–20 °С); 2 – (–10 °С); 3–0 °С;
4–10 °С; 5–20 °С; 6–30 °С; 7–40 °С; 8–50 °С – they have the character of straight lines in semi-logarithmic coordinates. The results of the study indicate sufficiently high critical stresses of concrete using a complex organic binder scr = 0.7 MPa. Consequently, coatings built from concrete mixes based on a complex organic binder will be durable under the action of traffic loads.
Key words: road asphalt concrete, viscoplastic secondary cubic residue of phenol-acetone production, modulus of elasticity, coefficient of plasticity.
Vitaly Bespalov, Kirill Kaplun, Mikhail Borisov, Denis Baburin, Evgeny Pakhomov
Cold Tar-Concrete with Adjustable Terms Formation of the Structure
Donbas National Academy of Civil Engineering and Architecture
Abstract. One of the effective ways to control the process of formation of the structure of tar concrete is the complex modification of low-viscosity coal binders with polyisocyanate and distillation residues of phthalic anhydride. This will make it possible to use coal tar with a viscosity C1030 = 10…50 s for the production of cold tar concrete mixtures and significantly reduce the mixture preparation temperature (40…70 °C), and as a result of the interaction of polyisocyanate with distillation residues of phthalic anhydride distillation (contains phthalic acid) and phenol-containing and amine-containing coal binder. It has been established that the optimal temperature for the production of a modified cold tar concrete mixture should be 40…60 ° C, the concentration of polyisocyanate is 4…6 % by weight of coal tar in the mixture, and ODA is 15…25 % by weight of tar. In this work, the initial period of structure formation of modified cold tar concrete and the mechanical properties of tar concrete at the age of one to five days were studied.
Key words: road asphalt concrete, cubic residues of distillation of ophthalmic anhydride, polyisocyanate (PIC), coal tar, plastic strength.