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  • Application of effective thermal insulation materials in building envelopes based on perlite, made by the method of self-compacting masses

    In this article is considered progressive technology for producing heat-insulating materials by the method of self-compacting masses. Implementation of this method will allow obtain a significant economic effect in comparison with traditional technologies. Due to the use of the effect of obtaining excess pressure in a closed perforated form from an increase in volume during heating of pre-expanded polystyrene granules, it became possible to remove excess moisture, reduce the time of the technological process, and reduce energy consumption. This method allows to combine several processes in one operation: compaction of the mixture, heat treatment, removal of excess moisture. As a result of theoretical and laboratory research and experimental-production approbation, the possibility of implementing of heat-insulating materials of a wide range of applications with improved operational properties into mass production has been obtained. Perlite concrete is one of the effective heat-insulating material, the production of which is possible using the method of self-compacting masses. An assessment of the qualitative efficiency of perlite concrete was carried out: the thermal conductivity coefficient is within the limits required for effective heat-insulating materials. It was concluded that the use of perlite concrete in construction is promising: it is possible to reduce the drying time in 10-12 times, eliminate drying shrinkage, eliminate mechanical processing of products after heat treatment, obtain products of various configurations and volumes, with an improvement in strength characteristics at a minimum density. In this article is considered progressive technology for producing heat-insulating materials by the method of self-compacting masses. Implementation of this method will allow obtain a significant economic effect in comparison with traditional technologies. Due to the use of the effect of obtaining excess pressure in a closed perforated form from an increase in volume during heating of pre-expanded polystyrene granules, it became possible to remove excess moisture, reduce the time of the technological process, and reduce energy consumption. This method allows to combine several processes in one operation: compaction of the mixture, heat treatment, removal of excess moisture. As a result of theoretical and laboratory research and experimental-production approbation, the possibility of implementing of heat-insulating materials of a wide range of applications with improved operational properties into mass production has been obtained. Perlite concrete is one of the effective heat-insulating material, the production of which is possible using the method of self-compacting masses. An assessment of the qualitative efficiency of perlite concrete was carried out: the thermal conductivity coefficient is within the limits required for effective heat-insulating materials. It was concluded that the use of perlite concrete in construction is promising: it is possible to reduce the drying time in 10-12 times, eliminate drying shrinkage, eliminate mechanical processing of products after heat treatment, obtain products of various configurations and volumes, with an improvement in strength characteristics at a minimum density.

    Keywords: method of self-compacting masses, heat-insulating perlite concrete, electric heating, closed perforated volume, bead polystyrene, energy efficient material

  • Strength characteristics of polyethylene terephthalate fiber concrete

    This article contains the results of a study of the strength characteristics of concrete with the addition of various amounts and shapes of recycled polyethylene terephthalate (PET) fibers. In general, the use of fiber in concrete from waste PET materials (obtained by mechanical grinding), rather than heat-treated, can increase the tensile strength. The compressive strength is reduced. Industrial flex is not recommended to be used as a fiber (additive) in concrete, as this leads to a decrease in strength characteristics. Increased tensile strength is provided through the use of specially prepared PET fiber. The conducted research proved the possibility of using PET fiber in concrete from waste PET materials (obtained by mechanical grinding) PET fiber is recommended for use in concrete structures to increase tensile strength.

    Keywords: concrete, concrete matrix, fiber, dispersed reinforcement, polyethylene terephthalate, tensile strength, compressive strength

  • Polimer concrete with dispersive reinforcement

    Polymer concrete is a concrete that uses polybutadiene, a polymer from the liquid rubber family, as a binder, so that it has elastic properties and is extremely resistant to aggressive chemicals, high water repellency and high compressive strength. It does not reveal the destruction typical for ordinary concrete, such as cracking and peeling. It has a high electrical resistance, increased mechanical compressive and tensile strength. In addition, polymer concrete is a durable material with water-repellent properties and resistance to aggressive chemical environments. The proposed polymer concrete uses a conventional aggregate, which is used to produce ordinary concrete, but a polymer is used as a binder. Also, the usage of non-metal composite reinforcement is proposed (APP patent No. 16983646). Below are the results of testing samples with three types of dispersed reinforcement.

    Keywords: polymer concrete, rubber concrete, composites, fittings, manufacturing methods, testing

  • Use of a complex modifying additive to expand raw materials sources of fine fibre-reinforced concretes

    Modern trends of the concretes studies have been considered. Properties of the materials and additives used have been cited. There has been undertaken designing an experiment on a complex modifying additive application for a fine fibre-reinforced fine-sand cocrete. The results of the studies undertaken have been analyzed with regard to their statistical significance. On the bases of the reseach results there have been acquired regression equations for objective functions responses, namely ultimate strength on both compression and bending, and average density of fine fibre-reinforced concrete. There have been produced contour plots and those of response function surface - ultimate strength under compression for all combinations of the both factors. There have been determined the composition of the modifying additive, which ensures maximal strength properties for fine fibre-reinforced fine-sand concrete.

    Keywords: fine concrete, complex additive, designing an experiment, strength, regression equation, plots of response function surface

  • Evaluation of the effectiveness of admixtures for dry building mixes with normalized indicators of adhesion strength to the base

    A method of selecting admixtures for the production of dry building mixes is proposed based on the results of an expert assessment of the complex indicator of the workability of application (connectivity, continuity when pulling with a toothed trowel, elasticity, quality of rollers) on a 100-point scale and the strength of adhesion to the concrete base, followed by the calculation of the specific cost of admixtures in the mixture per ton of products, respectively, by one point of workability of application and 1 MPa of adhesion strength, developed as a result of studies of adhesive mixtures made using 4 different cements, 5 water-retaining additives and 12 redispersible polymer powders. The possibility of obtaining adhesive compositions of adhesion class C 2 using redispersible polymer powders of domestic production is shown.

    Keywords: dry building mix, adhesion strength to the base, unit cost, processability of application

  • Technological and economic aspects of the development of the light concrete industry for structural purposes

    Concrete has unique properties that allow it to occupy a leading position in the market of building materials. General-purpose structural concrete is used for the construction of buildings and structures that can provide sufficient strength and elasticity for load-bearing and enclosing structures. Concrete production technologies are in constant development, inextricably linked with the solution of the most important task – reducing the mass of building materials, and, as a result, reducing the material consumption of construction

    Keywords: capital construction, structural concrete, heavy concrete, light structural concrete, resource saving, economic feasibility of using light concrete

  • Protection of residential buildings from external noise sources by special noise-proof structures

    The article considers the influence of external noise sources on humans and the environment as an environmental factor and ways to combat noise. The aim of the work is to study the external enclosing structures of residential buildings, the facades of which are oriented to a noisy highway on the example of residential complexes of the city of Rostov-on-Don and noise screens installed on the highway along the residential development of the city of Bataysk, Rostov region. A practical method of measuring the noise level using a noise meter is used. Acoustic measurements of the noise level were carried out, which made it possible to conclude about the effectiveness of the noise protection structures provided. It has been experimentally established that noise-proof structures reduce the sound pressure level to an acceptable level. When designing residential buildings, a simultaneous calculation of noise protection and thermal protection of buildings is necessary, determining the materials, the design of the outer wall, the thickness of the insulation layer and the choice of noise-proof windows. To improve the noise ecology near residential buildings and federal highways, it is recommended to use modern technologies for the construction of noise screens. According to the research results, it can be concluded about the effectiveness of the use of noise screens during their continuous construction along the highway.

    Keywords: noise, noise protection, noise shield, noise-proof structures, sound power level, sound insulation, ecology

  • Plasticization of mixtures based on oxychloride cement using additives

    The problem of maintaining the exact ratio between the components in mixtures based on oxychloride cement is described. This problem is solved by the use of additives plasticizing or water-reducing action. The results of studying the effect of the type of additives on the mobility of mixtures and the strength of hardened oxychloride cement pastes are presented. The positive effect of the use of additives based on naphthalene and melamine sulfoformaldehyde was shown. The negative effect of additives based on lignosulfonates on the strength of oxychloride cement pastes has been established. Assumptions about the reasons for the low efficiency of additives based on polycarboxylate esters are indicated. The positive influence of the plasticizing effect of additives on the homogeneity of the microstructure of oxychloride cement pastes is shown. An assumption about the reasons for the increase in strength when using additives based on naphthalene and melamine sulfoformaldehyde is made.

    Keywords: oxychloride cement, Sorel cement, plasticizer, water reduction, additive, modification, structure, strength

  • Evaluation of the effect of reinforcement parameters on the properties of fiber-vermiculite concrete composite

    The properties of fiber-vermiculite concrete composite are investigated. Analysis of the results showed that reinforcement with basalt fibers of the matrix increases the flame retardant properties. The presence of basalt fibers in the composite significantly increases the strength and flame retardant properties of the initial matrix and reduces the thickness of the flame retardant layer. The highest values of bending strength are achieved with a 0.9% reinforcement percentage and a ratio of fiber length to diameter equal to 1444.

    Keywords: composite, basalt fiber, reinforcement, vermiculite concrete, dispersed, strength, bending, flame retardant properties, compression, matrix, thickness, percentage of reinforcement

  • Comparative analysis of the console beam natural frequency using analytical and software approach

    Flexible structures typically have low flexible stiffness and a low material damping factor. Mild excitation can result in damaging high amplitude vibration and long recovery times. This can lead to fatigue, instability and poor performance. Vibration control of flexible structures is an important issue in many engineering applications, especially for precise performance in aerospace systems, satellites, flexible arms, etc.

    Keywords: natural frequency, flexible stiffness, vibration, Langrange's equation, Euler's method, damping force, beam theory

  • Influence of ground slag of steelmaking production on the properties of a composite slag-alkaline binder

    The hardening of steel-making slags is slow and the strength properties of the cement stone do not provide the specified operational properties. By creating an optimal composition (steelmaking slag + blast furnace) and chemical activation, a composite material with high strength is obtained. The compressive strength of concrete samples at the age of 28 days of hardening in a normal hardening chamber is 28 to 54 MPa. Caustic soda and sodium silicate were used as a chemical activator of hardening. The greatest strength is provided by the ratio of chemicals as NaOH: Na2 SiO3 × nH2O = 1: 1 and at a dosage of 8% of the mass of the composite slag-alkali binder. The optimum ratio of ground granulated blast furnace slag and steelmaking slag is 3: 1 to obtain high compressive strength and minimum water absorption in the early stages of hardening.

    Keywords: steelmaking slag, blast furnace slag, homogenization, hardening activator, hydration, strength

  • Fibroconcrete compositions for floor coverings in the construction of industrial and civil structures

    The results of the development of compositions of fibroconcrete floor coverings and the technology of their preparation for use in structures during the construction of industrial and civil structures are presented. The effectiveness of the use of polymer and basalt fiber fibers, as well as plasticizing additives in the manufacture of fine-grained fiber concrete is substantiated. As a result of the conducted experiments, the composition of fine-grained fiber concrete with the use of basalt fibers as fillers is proposed. Based on the calculation of the estimated cost, it was found that the use of fiber fibers in the concrete mixture instead of laying metal mesh allowed to reduce labor costs by about 2 times, reduce the amount of binder, and also improve the performance characteristics of floor coverings by increasing crack resistance and corrosion resistance.

    Keywords: floor coverings, fiber-concrete mixture, superplasticizer, basalt fiber, strength

  • The relevance of the use of basalt fiber in modern construction

    The purpose of the article is to study the material on the topic "Basalt fiber", to generalize the studied material and the accumulated experience on the given topic. The article discusses the advantages, disadvantages, problems of use and achievements in the study of basalt fiber used for the production of building materials as a reinforcing component. The analysis of the average cost of basalt fiber in comparison with other types of fiber is carried out, a conclusion is made about the advantage of using basalt fiber. General conclusions have been made about the advisability of using basalt fiber for the production of building materials, and unexplored areas of using this type of fiber have been identified.

    Keywords: basalt fiber, reinforcement, stress-strain states, compression, tension, bending, shear, deformation, adhesion

  • Features and possibilities of structural polymer concrete in modern construction

    The article considers the possibility of improving the physical, mechanical and environmental properties of polymer concrete by changing their component composition depending on the requirements for the operational characteristics of the construction object. Currently, the research of scientists is aimed at the development and implementation in construction practice of compositions of light building materials, the range of densities of which varies depending on the tasks set. Such an additive as glass, changing the physical properties of the material, significantly improves its characteristics, there are the following types of such concrete: glass concrete with fiber, concrete with optical fiber, with cullet, and also a solution where glass is used as a binding element. Liquid glass, when added to concrete, helps to improve the stability and strength of plaster and concrete structures. When using this material, you can find a lot of positive things. The environmental friendliness of the material expands the scope of its use, which is very important at the present time. The new material is easy to obtain, is made from affordable materials, has improved physical and mechanical characteristics, which makes it competitive among a wide range of products on the global construction market.

    Keywords: polymer concrete, liquid glass, glass concrete, optical fiber, cullet, modification, strength, composite material, glass fiber concrete, secondary raw materials

  • On the influence temperature conditions during concreting of massive monolithic reinforced concrete structures on the strength of concrete

    Ensuring the regulation of the temperature regime of concrete curing to prevent cracking due to temperature gradients and shrinkage deformations is one of the key points in the construction of massive monolithic reinforced concrete structures. A combination of prescription and technological ones are considered as the main methods for regulating the temperature regime of holding during concreting of massive monolithic structures. The analysis of temperature fields and an assessment of possible cracking of concrete during concreting of grillages of bridge supports, holding of concrete during the erection of structures, in which it was carried out by different methods. It was proposed to clearly stipulate in the normative documents the cases of mandatory tests for concrete frost resistance based on samples taken from the structures. When developing design documentation for standardizing concrete quality indicators, it was proposed that the values of the class of concrete in terms of compressive strength should first of all be assigned according to the condition of ensuring the durability of the structure, depending on the class of the operating environment.

    Keywords: massive monolithic reinforced concrete structures, temperature conditions of concrete curing, cracking, frost resistance, compressive strength class of concrete

  • Influence of granulated blast furnace slag on the properties of fine-grained self-compacting concrete.

    The results of a study of the influence of slags from various manufacturers on the spreadability, strength and shrinkage of self-compacting fine-grained concrete are presented. It was found that replacing up to 30% of cement with slag reduces the strength of concrete only in the initial period of hardening. It was shown that the use of slag can significantly reduce the shrinkage of concrete.

    Keywords: granulated blast furnace slag, mineral additive, fine-grained concrete, self-compacting concrete, mixture flow, strength, shrinkage

  • Facade systems device. Innovative technologies and materials

    The article discusses the possibility of using new generation lightweight materials in construction. The author analyzed the distinctive features of membrane structures, revealed the advantages and disadvantages of the ETFE film. Based on the analysis, it was concluded that these materials and technologies are an easy and promising alternative to traditional ones.

    Keywords: innovative facade systems, textile architecture, membrane structures, ethylene-tetrafluoroethylene copolymer film, energy efficiency

  • Modern corner joints of factory-made glued beams

    As the object of research, the angular joints of glued wooden structures used for the construction of external enclosing structures in low-rise housing construction, made in factory conditions with modern equipment, were selected. As part of the work, the available literature on this topic was analyzed. The analysis of the variability of the use of modern corner joints of external walls for low-rise construction, made of glued beams, in the design and construction, taking into account the development of technical capabilities in modern industries. Describes the old and new device technology, corner joints, indicating the advantages and disadvantages of such compounds, describes the technical characteristics of the used elements. Conclusions are drawn, as well as recommendations for the further use of these materials in design and construction.

    Keywords: glued wood, structural features of corner joints, production of wooden structures

  • Methodology for optimizing the process of designing pavements using asphalt granulate

    A methodology for the development of a system of typical environmentally and economically effective road pavement designs is proposed, which allows to optimize the process of designing pavements using asphalt granulate for the design of overhaul of road pavements.redistribution of investments in interests of the organization and development of new production on available floor spaces. The most important organizational economic targets of a diversification of management are presented by innovative activity of the industrial enterprise.

    Keywords: cold deep in-place recycling, pavement, standard design, road, design, construction, asphalt granulate

  • Porous ceramics based on hydrolyzed lignin

    Hydrolysis lignin is a waste product of hydrolysis production (wood that has undergone thermochemical treatment). Lignin is of particular interest in the production of building materials, since it is unique in its chemical composition and physical properties. At the same time, the use of lignin at the present time will reduce the technogenic load on the environment, since the dumps of this waste occupy large areas, harming the ecology of cities. The purpose of this work is to study the possibility of obtaining effective ceramic products based on production waste for external enclosing structures. The article presents the results of determining the optimal percentage of the content of the burnout additive in the production of porous ceramics. The work shows the dependence of the change in physical and mechanical properties on the content and composition of the additive. It is shown that the best indicators are characterized by compositions with a 1: 1 content of lignin and sawdust in addition. The authors investigated shrinkage deformations during ceramics firing and drying. It is shown that when using the hydrolysis lignin of the Ust-Abakan plant, there is no loosening of the samples during sintering.

    Keywords: waste, recycling, hydrolysis lignin, ceramic products, sawdust, porosity, shrinkage, density, water absorption

  • Analysis of the use of industrial waste in the production of building materials

    Of the industries that consume industrial waste, the construction materials industry is perhaps the largest. The research has determined that the use of industrial waste can cover up to 40% of the construction needs for raw materials. The use of industrial waste reduces the cost of manufacturing construction materials compared to the production of their natural raw materials by up to 30%. The achieved savings in capital investment is approximately 35 ... 50%.

    Keywords: industrial waste, effective additives, cost reduction, performance improvement, environmental problem solving

  • Influence of slag-alkali binder structure modifiers on cracking

    The purpose of the study is to determine an effective modifier of the structure of a slag-alkaline stone, characterized by a low value of linear shrinkage and a decrease in cracking in the early stages of hardening. Ground blast furnace slags were activated with aqueous solutions based on sodium silicate and caustic soda. Fly ash and zeolite-containing clay were used as modifiers of the cement stone structure at a dosage of 5, 10 and 15% of the binder consumption. The results of the study showed that an increase in fly ash content does not significantly affect the setting time. The use of zeolite-containing clay as a slag-alkali binder modifier makes it possible to regulate the setting time of the binder at a dosage of more than 10%. Cracking of the slag-alkaline matrix was observed only for mixtures without fly ash and zeolite-containing clay.

    Keywords: cement stone, slag-alkali binder, hardening activator, structure modifier, fly ash, zeolites, shrinkage, cracking

  • "The Application of industrial wastes for production of crushed stone-mastic asphalt concrete "

    Crushed stone-mastic asphalt concrete is a more durable material compared to traditional asphalt concrete. But for its exploitation, high-quality mineral powders and bituminous carriers are needed to prevent bitumen from flowing out of the composition. Today, the carbonate rock powders and bituminous carriers from natural cellulosic fibers are widely used. However, many Russian Federation regions, including the Krasnoyarsk Territory, are not provided with these materials, and they are also really expensive. The purpose of our work was to reduce the cost and improve the properties of crushed stone-mastic asphalt concrete. The task of the research was to develop gravel-mastic asphalt concrete compositions using the industrial waste from the Krasnoyarsk Territory. Nepheline sludge was tested which is the waste of the alumina plant in Achinsk and rubber crumb with inclusions of cord fiber of Chernogorsk in Krasnoyarsk Territory. The chemical composition and physical and mechanical properties of these wastes were studied. Gravel-mastic asphalt concrete compositions were made by using these wastes. The tests showed that the received compositions met regulatory requirements. The developed compositions were introduced by “Krasnoyarskavtodorom” on the Krasnoyarsk Territory roads. The economic effect of the waste usage is achieved through the exploitation of the local raw materials, which leads to a reduction of the transportation and energy costs.

    Keywords: the crushed stone-mastic asphalt concrete, industrial waste, nepheline sludge, mineral powder, bituminant, rubber waste with corded fiber inclusions, crushed stone, sand Crushed stone-mastic asphalt concrete, industrial waste, nepheline sludge

  • Thermal changes of steel-fiber concrete with different parameters of dispersed reinforcement after exposure to high temperatures

    The work is devoted to the study of thermal deformations and changes in the properties of steel-reinforced concrete after heating them to high temperatures in connection with the use of steel-reinforced concrete panels as permanent formwork of prefabricated monolithic structures of nuclear power plants. Thermal changes of steel-fiber reinforced concrete have been studied in other works. However, the results obtained in these studies do not correspond to the features of the work of steel-fiber concrete in the panels of fixed formwork. Not all major thermal changes have been investigated. In this regard, in this work, tests are carried out on sample plates. Thermal changes after heating at temperatures from 110 to 1100 oC of mass, density, size, flexural strength, ultrasound transmission rate, and water resistance are studied. Samples of 23 compositions made on the basis of a cement-sand matrix using five types of steel fiber with a volume content from 0.5% to 6%, as well as samples of the matrix, were studied. It was found that after heating, there is a decrease in mass and density, a change in size (mainly a decrease after 110-600 oC and mainly an increase after 800-1100 oC), a change in bending strength (mainly an increase after 110 – 300 oC and a decrease after 400 – 1100 oC), a decrease in the speed of ultrasound transmission and the water resistance of steel fiber concrete. It is found that the dependence of thermal deformations and changes in the properties of steel-fiber concrete on the heating temperature, volume content and type of fiber is not monotonous and variable at different values of these factors. Moreover, the thermal changes of fiber-reinforced concrete do not always correspond to the expected ones, based on theoretical concepts. The reasons for this phenomenon are shown. It is noted that it is necessary to conduct further numerical analysis of the obtained results in order to identify the true, not masked by other processes, influence of temperature, type and volume content of fiber on the thermal changes in the properties of steel fiber concrete after heating.

    Keywords: steel fiber reinforced concrete, temperature impact, change in mass, change in ultrasound speed, change in water resistance, change in strength

  • On the work of fiberglass pipes in engineering heat supply systems

    The example of application of fiberglass pipes on epoxy binding at replacement of steel pipes in heat supply system is considered. Fiberglass pipes in the deals with the influence of the degree of polymerization of the binder in the composite material of pipes that does not comply with the normative values on the work of the elements of the heat supply system when the coolant passes through it. When installing pipelines made of composite materials based on thermosetting polymers operating at elevated temperatures, it is necessary to control the supplied products for compliance with its regulatory requirements with mandatory control of the degree of polymerization of binders.

    Keywords: fiberglass pipes, degree of polymerization, linear thermal expansion, shrinkage stresses, quality indicators, operation