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
The results of the development of a set of indicators for the quality of construction products on the example of a reinforced concrete pile are presented. The analysis of the requirements of regulatory documentation for the evaluation of aesthetic indicators of the product is carried out. A solution to the dispute between the Supplier and the Customer on the issue of assessing the quality of the concrete surface is proposed.
Keywords: quality management, improving competitiveness, consumer requirements, quality indicators, technical level, aesthetic indicators, construction
The article is devoted to solving the issues that arise when choosing the issues of materials for use on the sites of oil fields. The basic concepts of composite materials are revealed. The article presents the prerequisites for the introduction of composite materials for the oil and gas industry. The examples of structures using CM that are used today are presented. The advantages of using a composite material are revealed. An overview of the problems of its implementation in Russia is made. The advantages for construction work when using this material are determined. The minuses of CM, methods of dealing with their flaws are also considered. A detailed analysis of the modern composite materials market takes place.
Keywords: composites, construction and installation works, automation, composite materials, overpasses, fiberglass
In connection with the increase in production activity in the winter and in remote areas, in regions close to the regions of the Far North, the use of new building materials is required. One of the most common building materials is concrete. This article describes an experimental study of the concrete substitute "HILST" for compliance with the manufacturer's declared characteristics: the ability to mix, hardening at room temperature and under adverse conditions.
Keywords: building materials, concrete, concrete substitute, HILST, mixing, experiment, adhesion, building chemistry, hydrophobicity, foundation
According to regulatory requirements, the Khakassia Republic is characterized by high seismicity, and therefore reliability and safety requirements are imposed on buildings and structures in accordance with SP 14.13330.2014 “Construction in seismic regions”. It is necessary to significantly reduce or eliminate the likelihood of an emergency, to ensure the necessary margin of safety and durability of buildings. It is possible to achieve such a multifaceted effect, including through the introduction of construction technologies using fiber-reinforced concrete. The experience of Russian and foreign researchers shows that the use of fiber-reinforced concrete in various structures makes it possible to achieve higher tensile strength, no shrinkage and resistance to cracking, as well as high impact strength and plasticity. In this regard, the study of the possibility of using fiber-reinforced concrete in the conditions of the Khakassia Republic is relevant. The purpose of this work is to study structures using fiber-reinforced concrete based on basalt fiber, which has increased strength, as well as to analyze the stress-strain state of models of various structures. The article presents the results of determining the optimal percentage of concrete reinforcement with basalt fiber based on the study of the kinetics of changes in strength in compression and bending. The paper presents the dependences of changes in strength and shrinkage deformations on the percentage of reinforcement. It is shown that concretes with 2% fiber content are characterized by the best performance. It is noted that an increase in the percentage of fiber reinforcement does not always lead to an increase in strength due to the uneven distribution of fiber throughout the volume. The authors investigated the stress-strain state of bending elements (slabs, beams) based on fiber-reinforced concrete. It is shown that when using basalt fiber, there is a decrease in the percentage of reinforcement with working reinforcement of reinforced concrete elements to 26–57 %.
Keywords: Fiber concrete, basalt fiber, percentage of reinforcement, bending element, shrinkage, deformation, stress-strain state, compressive strength, flexural strength, steel economy
This article discusses the use of local additives and waste for the production of building materials and products. This topic is very relevant at the present time, since a large amount of waste has been collected all over the world, which occupies huge areas of fertile land and pollutes the environment around us, and we also considered the issue of increasing the quality of concrete by chemicalization.
Keywords: construction, building materials, waste, additives, environmental pollution, ecology, new technology
On the territory of the Perm Region there are a large number of deposits of carbonate rocks. Their application in various industries is limited due to the high amount of impurities, so to expand the scope of application of local carbonate rocks, it is proposed to use chemical methods for obtaining deposited chalk, which were considered in the article. The most rational method seems to be the carbonation of calcium hydroxide with carbon dioxide. The implementation of this method is possible at commercial lime production plants, which will not only solve the important environmental problem of carbon dioxide emissions in such industries, but also will allow expanding the market for high-quality calcium carbonate, which is in demand by various industries.
Keywords: calcium carbonate, chemically precipitated chalk, lime, calcium oxide, calcium hydroxide, carbon dioxide, carbonation, commercial lime
The results of the analysis of quality parameters of building materials used for insulation of walls of residential buildings are presented. The problem of increased consumption of thermal energy for heating needs is identified, the solution of which is to increase the thermal characteristics of the enclosing walls of buildings by means of their insulation and protection by the system of a hinged ventilated facade.
Keywords: Hinged ventilated facade, thermal characteristics, influencing factors, energy efficiency
This article discusses the most common materials and how they are used to protect against ionizing radiation used for medical purposes. Comparison of technical and economic devices for the construction of a protective fence from the described radiation protection materials is presented. The effectiveness of the use of self-adhesive polymer radiation-shielding materials for protection against insulation with voltage up to 100 kV has been established.
Keywords: gamma radiation shielding, radiation shielding, EPDM, metal oxide, barite, polymer composites
The article discusses the possibility of increasing the physical and technical properties of the sands of the Usklyai field in the Republic of Mordovia from the technological modes of their enrichment. The prospect of their enrichment due to preliminary screening and washing with water is proved.
Keywords: building sand, cement concrete, mortar, particle size modulus
It describes the material CLT, which is used for the manufacture of floor slabs. The required floor thickness is calculated from the condition of rigidity under a load of 2.4 kN / m2 for various spans. The values of deflections are determined from the stiffness condition. The calculated deflection values are compared with the standard values. Based on these results, the recommended floor thickness is assigned for each span.
Keywords: cross-laminated timber, timber constructions, floor, deflection, rigidity
The article investigates the physical and mechanical properties of fine-grained fiber-reinforced concrete with metal, polypropylene and polyamide fibers, using Portland cement, hyperplasticizer. Comparison of strength characteristics of fiber-reinforced concrete made using metal fiber, polypropylene and polyamide fibers is carried out. A technical and economic comparison of the efficiency of using fibers of various origins has been made. According to the cost calculations, the use of polyamide fibers is cost-effective, since the cost of materials is lower than the cost of fiber-reinforced concrete materials based on polypropylene fibers of this composition.
Keywords: fiber concrete, hyperplasticizer, fiber, microsilica, tensile strength, nature of destruction, mechanical property, polypropylene fiber, polyamide fiber, cement, reinforcement, adhesion, monolithic structure, cost
The results of the development of compositions and technologies for their preparation for use in the structures of marine gravity oil and gas production platforms and underwater oil and gas pipelines are presented. The efficiency of using basalt fiber fibers, plasticizing additive "Sika ViscoCrete 5-800" and soot waste from thermal power plants in the manufacture of fine-grained concrete is proved. As a result of the experiments, the strength characteristics of fiber concrete were determined depending on the amount of superplasticizer and soot waste introduced when using equal-moving mixtures. An increase in the compressive and Flexural strength of samples modified with basalt fiber, superplasticizer and industrial waste is shown, which contributes to an increase in the operational characteristics of oil and gas offshore structures by increasing the parameters of frost resistance and water resistance of structural materials.
Keywords: oil and gas facilities, fiber-reinforced concrete mixture, the superplasticizer basalt fibre, particulate waste strength
This article discusses the problem of increasing the load-bearing capacity of bored piles. The technology of injecting fixing solutions into the ground under the foundations of a two-story building in the city of Azov to increase the load-bearing capacity of bored piles was described.
Keywords: structurally unstable soil, pile Foundation, load-bearing capacity, soil consolidation, silicatization, camouflage broadening, driving piles, bored piles, screw drilling, concreting
The use of laser radiation for welding aluminum alloy AD33 can improve the quality of welded joints and process performance. At the same time, most of the welded structures in production are performed using automatic laser welding installations, which allow ensuring the necessary quality of welded joints, including due to the constancy of the technological process modes. However, there are a number of industries where manual laser welding installations are indispensable and in high demand. At the same time, a distinctive feature of the manual laser welding process is the problem of ensuring the constancy of the duration of exposure to laser radiation on the surface of the workpiece when the speed of the laser beam changes. The paper presents the results of a comparative study of the dependence of the quality of the AD33 aluminum alloy welded joint on the change in the speed of the laser beam for manual and automatic laser welding conditions.
Keywords: aluminum alloy, laser radiation, welding, welding bath, technological process, microstructure, AD33, laser beam, manual laser welding, Al–Mg–Si, aluminum thermal deformation coefficient, vacuum chamber, pulsed laser
The results of scientific and experimental research on determining the width of the crack opening in concrete under the influence of mechanical load are presented. In the process of scientific research, a simultaneous complex measurement by tensometric and acoustic methods of the load of deformation, the width of the crack opening, the total count of acoustic emission was carried out to obtain complete diagrams of concrete deformation. As a result of the experiments, regression equations were obtained and the correlation dependence between the crack opening width and the total acoustic emission count was established.
Keywords: lightweight concrete, crack width, tensometric method, acoustic emission, deformation diagrams
Increased concrete strength due to early loading is one of the priorities of concrete technology. Many articles contain data on changes in compressive strength after early loading. The first person to test early concrete loading was Satalkin. He tested bridge supports for static and dynamic loads. The results of his work became the basis for further research in the field of early loading of concrete. The objective of this work is to study the tensile strength in bending after early loading and to check the influence of the orientation of the samples under load. Also we considered the effect of active mineral additives on this parameter. The object of study is samples of cement-sand dough prepared on a Portland cement binder of various manufacturers. We noted a difference in the strength characteristics in bending by changing the orientation of the samples when testing them after early loading. The maximum increment of strength is noted in a plane perpendicular to the direction of compressive force. The use of a mineral additive with the replacement of a fraction of cement gave the attenuation of the observed effect.
Keywords: anisotropy of strength properties, early loading of concrete, cement composite, flexural strength, mineral additive
The results of optimizing the composition of concrete based on aggregates from crushed concrete are presented. With the help of mathematical and natural modeling matched the composition of the expanding agents sulfoaluminate type, the optimal percentage of components of the modified cement required for producing a material with improved performance characteristics, the mathematical model construction and technical properties of the concrete and the kinetics of their changes to take into account the time factor and strength and weathering.
Keywords: mathematical modeling, expanding additive, factor experiment, influencing factors, level of variation, experiment planning matrix
The search for technological solutions for the organization of lean production at precast concrete enterprises was carried out. Options for rational use of rock crushing screenings as a filler and filler for self-compacting fine-grained concrete are considered. The optimal dosage of limestone crushing screenings in the composition of fine aggregate for the preparation of self-compacting mixtures has been determined. It was found that the enrichment of very fine Sands with large fractions of Sandstone crushing screening in an optimal amount reduces the intergranular voidness and reduces the water demand of the fine-grained mixture.
Keywords: lean production, rock crushing screenings, optimization of grain composition of aggregate, self-compacting fine-grained concretes, superplasticizer based on polyaryl and polycarboxylate esters
A scheme and procedure for carrying out emanation tests of radon-protective coatings on standard concrete samples are proposed. The results of testing the material "Silor-Ultra" as an effective radon protective coating are shown.
Keywords: radioactivity, radon, radiometer, concrete, standard sample, antiradon protection, radon protection coating, radon insulation, emanation tests
The analysis is made of the use of expanded clay gravel in cement-sand mortar in order to reduce ice at the boundary between the pile and the mortar. The application of expanded clay concrete in block-modular buildings is considered. Lightweight design and reduced heatloss are proven.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
Fiber-reinforced concrete is a promising type of concrete, which in the near future may take a fairly large share in the total volume of concrete produced. Dispersed reinforcement fibers are a versatile material that can be introduced into various types of concrete. This additive may later be as common as plasticizers for modern concrete mixes. Fibro fibers can be used for the production of concrete products in stationary reinforced concrete plants or on-site installations for the production of ready-mixed concrete. The paper examines the influence of parameters on the index of bending strength of the material, as the main one, which is aimed at the introduction of fiber. The results of the influence of the characteristics of dispersed reinforcement on the effectiveness of the introduction of these additives and the final construction and strength properties of heavy concrete are described.
Keywords: dispersed reinforcement, basalt fiber, polypropylene fiber, fiber concrete, prismatic strength, Flexural strength
This study presents the results of the development of a polymer composite material with good dielectric properties, which allows it to be used in the radio and electrical industries. This material is based on epoxy resin, polyethylene polyamine, hollow glass microspheres and gallium oxide. The use of hollow glass microspheres in the composition in an amount of 5-20 wt. h. reduces the dielectric losses, and the use of gallium (III) oxide in an amount of 5-15 wt.h. it makes it possible to increase the stability of the dielectric characteristics when working in the microwave radio range and reduce the dielectric loss. Studies have shown that a sufficiently effective composite polymer material with high physical, mechanical and dielectric properties can be obtained on the basis of the developed composition.
Keywords: composite material, epoxy resin, hollow glass microspheres, gallium oxide, permittivity, dielectric loss tangent
Geopolymers are a promising building material that can become an alternative to Portland cement. They are distinguished by the possibility of using industrial waste, in particular metallurgical slags as well as inexpensive liquid glass. These resource-efficient binders can be used for the production of concrete products in stationary factories or workshops. The paper provides general directions for regulating the structure formation and properties of geopolymers based on metallurgical slags mixed with activators. The mechanism of geopolymer hardening based on the interaction of non-active slag components with an alkaline activator is briefly described; it is a three-stage physical and chemical process that leads to the formation of a solid stone structure. The influence of raw material properties on the final product characteristics is described.
Keywords: geopolymer, geopolymer concrete, aluminosilicate component, alkaline activator, metallurgical slag, basicity modulus, strength
The article deals with obtaining RDF fuel based on solid municipal waste. The expediency of using this type of fuel in the cement industry is justified, since its combustion in cement furnaces has less impact on the environment due to the high temperature level of the process. The composition of RDF fuel by elements is analyzed. Due to the fact that this fuel from different sources has a difference in the heat of combustion of two times or more, the heat of combustion of RDF fuel for the middle zone of Russia was experimentally determined and its compliance with GOST R 55127-2012.
Keywords: solid municipal waste, MSW, Recycle Derived Fuel, RDF fuel, lower combustion heat, ash content, alternative energy source, colorimetric bomb