The article is devoted to innovative approaches to the use of environmentally safe polymer binders in the production of thermal insulation materials (TIM) based on vegetable raw materials. The relevance of the work is due to the need to replace traditional synthetic polymers such as polyurethane foam, polystyrene foam, and mineral wool, which in the process of operation emit toxic substances with cumulative properties. Research shows that the use of biopolymers and renewable resources, such as castor oil-based polyurethane resins and casein adhesives, can significantly reduce environmental burdens and improve material safety. Special attention is given to thermoplastic and thermoset matrices, their properties, and applications in composite materials. Thermoplastics such as polyethylene and polypropylene have high impact resistance and recyclability but are limited in application due to the difficulty of processing and high melting point. Thermoset matrices, despite their high strength and resistance to chemical attack, are molded only once, making them difficult to recycle. This article discusses the advantages and disadvantages of different polymer binders and their prospects in the context of environmental sustainability and the efficiency of thermal insulation materials. The research is aimed at improving the physical and mechanical properties of composites and optimizing production processes to create affordable and environmentally friendly thermal insulation materials.
Keywords: innovative approaches, environmentally safe polymers, thermal insulation materials (TIM), plant raw materials, biopolymers, renewable resources, thermoplastics, thermosetting matrices, environmental sustainability, physical and mechanical properties
The research aimed to investigate the properties of glass-basalt composite tubes, specifically examining the relationship between structural fractal dimensions, composition, and mechanical properties. Physical experiments were carried out to assess the properties of glass and glass-basalt composite tubes. These tests included measurements of tensile strength, modulus of elasticity, fracture resistance, flexural strength, and additional mechanical characteristics. Fractal analysis of rovings and epoxy binder was performed at the microstructural level to evaluate the impact of structure on mechanical performance. Through predictive modeling of the physical and mechanical properties of glass-basalt composite tubes, an optimal range of properties was identified. This range is defined by specific technological parameters: rovings content of 68–74%, basalt fiber diameter of 7–12 μm, and epoxy binder content of 21–27%. Within this framework, the production of tubes with the following target properties was predicted: tensile strength, compressive strength , and modulus of elasticity.
Keywords: fractal modeling, microstructure, matrix fibers, glass-basalt plastic, composite material, forecasting, strength, fractal dimension, heterogeneity, mechanical properties, composite pipe, glass fiber, basalt, correlation analysis
The paper deals with a new composite material for waterproofing the underground parts of buildings and structures. The composite consists of Portland cement, fine aggregate, a complex additive, and chemical additives. Based on experimental data, the main physical and mechanical properties of the material have been determined. The results show that the resulting composite material has high physical and mechanical characteristics and can be used to protect concrete underground structures from groundwater damage.
Keywords: underground structures, durability, protection, waterproofing, composite material, complex additive, strength, crack resistance, adhesion, elasticity
The composition of the lightweight plaster mix includes the following components: hydraulic binder, crushed volcanic tuff-scoria (as a fine lightweight filler), reinforcing fiber and synthetic additive. The hydraulic binder consists of Portland cement and finely ground volcanic tuff. Plaster mixes based on volcanic tuff are in demand in regions with a warm or sharply continental climate: high temperatures during the day or low at night, including Ethiopia. The purpose of the research presented in the article was: to form material structure models that allow evaluating the material properties and evaluating the solutions obtained during the implementation of an active experiment. As a result of the experiment, optimal values of the main components of the plaster mix based on volcanic tuff were established, which is present in the mixture as a light fine filler and as a component of the hydraulic binder. Modeling of the material structure and engineering interpretation of its properties were carried out.
Keywords: plaster material, tuff-scoria, pozzolanic activity, mathematical modeling, analytical optimization
Bamboo as a building material has its own characteristics. It works well in stretching and bending. Bamboo has only longitudinal fibers that are prone to splitting, however these fibers are twisted in a knot. This phenomenon reduces the tensile strength. The mechanical properties of bamboo describe its reaction to physical influences. In general, bamboo has a high tensile strength parallel to the fibers. This article describes the mechanical properties of a bamboo rod depending on the loads, as well as modulus of elasticity of various types of bamboo. This article summarizes the experience of building buildings made of bamboo elements.
Keywords: bamboo, fibers, knot, joint, strength, construction, deformation, stretching, mechanical properties, anisotropic material
During the construction and operation of oil and gas industry facilities, there are increased requirements for the quality of concrete. To this end, it is necessary to use new formulations and their preparation technology to obtain concretes of the required density with high strength, frost resistance, water resistance, crack resistance and, ultimately, increased durability. The use of a superplasticizing additive, basalt or polymer fiber and a nanocarbon additive in the specified amounts in the composition of fine-grained concrete contributed to an increase in the uniformity and density of the mixture and, accordingly, an increase in the strength characteristics of concrete at various hardening times. As a result of testing concrete samples for frost resistance, a mark of 400-500 cycles of freezing and thawing was obtained. This makes it possible to use these compositions of fine-grained concrete in harsh climatic and difficult engineering and geological conditions of construction and operation of oil and gas industry facilities.
Keywords: fibroconcrete, oil storage tanks, nanocarbon tubes, basalt fiber, superplasticizer
In the process of drilling oil or gas wells, increased friction forces of the drill string against the walls of the well, as well as in the rock-crushing tool. The use of various formulations of washing liquid using surfactants from fish production waste contributes to solving a significant part of the problems. The presence of fatty acids in fish waste, which have a significant surface-active effect, allows them to be used as plasticizing additives in concrete. As a result of the introduction of these wastes into the concrete mixture, its rheological properties are improved, as well as the strength characteristics of the hardened fine-grained fiber concrete significantly increase. The use of fish production waste in the concrete mixture will reduce the cost of concrete production, and the environmental situation will improve due to the disposal of industrial waste.
Keywords: fiber concrete, strength, fish waste, industrial liquids, nanocarbon tubes, basalt fiber, superplasticizer
A brief historical overview of the evolution of requirements for the performance properties of wall materials is given. It is shown that the list of types of wall materials used is regulated by the level of urbanization of society and modern requirements for energy and resource conservation. An analysis of the types of defects that occur in multilayer walls of buildings during their operation has shown that the most important cause of their occurrence is an incorrect combination of materials with different porosity. The importance of taking into account the "single-layer" factor in construction, which allows ensuring the quality of construction and operation of buildings in Russia's diverse and difficult climatic conditions, was noted. Information is provided on the product range and operational advantages of non-autoclaved fiberfoam concrete as a material suitable for the construction of single-layer walls and capable of improving their protective and acoustic properties.
Keywords: safe use of premises, energy-efficient construction, gas-filled concrete, multilayer walls, mold, fiberfoam concrete, strength, thermal conductivity
The research aimed to investigate the structure of glass-basalt composite pipes and explore the relationship between their Renyi statistical dimensions and physicomechanical properties. Physical experiments were conducted to measure and analyze the elasticity of glass-basalt composite pipes. The experiments included testing the modulus of elasticity and other mechanical properties. Fractal analysis was applied at the microstructural level to assess the influence of the fiber matrix structure on the physicomechanical behavior of the pipes. The study explored the possibility of modeling the microstructure of glass-basalt composite pipes using 3D fractal analysis. A correlation was established between the spectrum of multifractal dimensions (D-200, D0, D1, D2, D200), the heterogeneity of the fiber matrix f(α), and the elasticity properties (Young’s modulus). For the obtained fractal models predicting Young’s modulus, the correlation coefficients (R2) were 0.95 for D0, 0.92 for D1, 0.90 for D2, 0.82 for D-200, and 0.68 for f(α). These results can be applied for rapid estimation of Young’s modulus using optical microscopy and photomicrographs of the microstructure.
Keywords: fractal modeling, microstructure, physicomechanical properties, material development, glass-basalt fiber, polymer pipes, forecasting, interphase boundaries, mechanical properties, fractal dimension, heterogeneity
The article is devoted to the systematic approach to the development of new composite building materials with lignocellulosic fillers, special attention is paid to the study of their thermal stability. The desire to increase the thermal stability of cellulosic materials implies the use of various modification methods, including acetylation and the use of flame retardants. The properties of monoethanolamine (NB)-trihydroxyborate (MEATHB) as a modifier to improve the fire resistance of thermal insulation materials based on stems of Sosnovsky's borer have been investigated. Experimental methods include thermogravimetric and differential scanning analysis, which allowed the evaluation of thermal decomposition and thermochemical transformations of the raw materials used. The results show that pre-modification using MEATGB shifts the peaks of cellulose thermo-oxidative decomposition temperatures to higher ranges, indicating an increase in the thermal stability of the materials. It is also found that the combination of modification using polyurethane and casein binders improves the thermostatic characteristics, which opens new perspectives for the creation of biostable thermal insulation materials. Thus, the results of this work can serve as a basis for further research and development aimed at creating innovative composite materials with high temperature resistance and biostability using available and environmentally friendly plant raw materials.
Keywords: composite materials, lignocellulosic fillers, thermal stability, monoethanolamine(NB)-trihydroxyborate, biostability, thermal insulation materials, thermogravimetric analysis, polyurethane binder, casein glue
This article discusses the use of dolomites from the Bosninsky deposit in the production of building materials and products. This topic is very relevant at the present time, as the construction industry is developing, new types of structures are appearing, higher requirements are imposed on the physical and mechanical properties of concrete mixtures. Large volumes of concrete mix production require the use of local component deposits to improve technical and economic performance.
Keywords: construction, building material, dolomite, environmental pollution, ecology, concrete mix, new technology
The analysis of ultrasonic effect on mixing solutions and hydrophobization of solid phase in suspensions for construction purposes is carried out. It is shown that ultrasonic treatment leads to an increase in the mass content of particles with a radius of 2-7 μm in the mixing solution, which contributes to an increase in the relative tensile strength of the samples obtained on its basis. Ultrasonic treatment of suspensions with the same relative degree of hydrophobization of the solid surface led to different contact angles of wetting of solid particles: Ө = 120, 450, 930, 69.40 for clay, cement and silica particles. Ultrasound leads to a significant decrease in the volume fraction of liquid in a three-phase foam stabilized by hydrophobized clay particles, compared to the syneresis process in a gravitational field.
Keywords: three-phase foam, silica suspension, clay, ultrasound, mixing solution
The article deals with the influence of complex mineral additive "chemical water treatment sludge + flask or fly ash" on the frost resistance of building mortars depending on the redispersible polymer powder dosage from 0 to 3%. According to the results of research after 100 freeze-thaw cycles, the condition RF/R0 > 1.2 is met, and the k value according to clause 5.2.4 of GOST 10060-2012 after 100–125 freeze-thaw cycles ranged from 0.94 to 1.73, the minimum value of the relative modulus of elasticity EF/E0 = 0.97, and the residual expansion deformation did not exceed 0.03%. Building mortars with fly ash have higher frost resistance according to the bending strength criterion in comparison with mortars with flask. The frost resistance criterion for bending strength is more “strict” than the criteria according to GOST 10060-2012. It is not advisable to use a dosage of RPP greater than 2% for the production of building solutions with increased frost resistance requirements.
Keywords: frost resistance of building mortars, frost resistance criteria, redispersible polymer powders, compressive and flexural strength, elastic modulus, permanent expansion deformation
The paper studies the dynamic-mechanical characteristics of styrene-isoprene-styrene, polybutyl methacrylate, thermoplastic polyurethane block copolymers and their blends by dynamic mechanical analysis. It is found that blending of several types of polymers allows to extend the range of effective vibration absorption. A combination of polymers with high damping properties over a wide temperature-frequency range was determined. The influence of vibration frequency on dynamic-mechanical properties of composites has been investigated.
Keywords: polymer composite material, dynamic mechanical analysis, polybutyl methacrylate, thermoplastic polyurethane, styrene-isoprene-styrene block copolymer, vibration absorption, damping material, glass transition temperature
The requirements for the energy efficiency of building structures are based on the balance of costs for their manufacture, operation and the effect that is achieved by saving heat. In conditions of relatively low cost of energy carriers, the use of seamless insulation systems, including those based on light or heat-insulating plasters, becomes expedient. The developed facade light plaster system has, at an average density of 400–500 kg/m3, adhesion strength to the substrate of 1.3–1.6 MPa; compressive strength of 4.7–5.5 MPa; frost resistance of 50 cycles. The system has thermal in-sulation up to 0.12 W/(moС), which, with a plaster coating thickness of 50 mm and a thermal resistance of the main structure of 1.6-2.0 m2oС/W allows you to obtain a system with a total thermal resistance of up to 2.3 m2oС/W, which fully meets the conditions of comfort or technological requirements.
Keywords: adhesive strength, energy efficiency, seamless insulation, thermal resistance
In the article, a floating liquefied natural gas plant located on a marine gravity platform in the Murmansk region was chosen as the object of research. The results of the development and selection of optimal concrete compositions using fiber fillers and modifying additives are presented. A set of works has been performed to determine the effect of basalt fiber fibers, as well as plasticizing additives on the structure and strength of fine-grained fiber concrete. Their advantages are shown and proposed for use in the constructions of tank hulls and other objects on a marine gravity platform.
Keywords: fibroconcrete, gas storage tanks, gravity platform, basalt fiber, superplasticizer
Authors considered the thermal inertial properties of some building envelope constructions which included the changes of internal surface layer materials. Researchers described the thermal and physical characteristics of 6 building surface layer materials. It has been determinate the radiant temperature of building envelope inside surface with changes of wall construction after 225 hours cooling process and initial temperature equal to +23 оС. Authors defined the cooling time of building envelope inside surface to 0 оС at different types of surface layer materials. Numerical experiment was done with modern program complex “Stf”. Modeling process was completed in program which was realized with finite difference method and constant heat transfer coefficient. There are new experimental results which were determinate during the research and realizing the mathematical model of non-stationary element’s cooling process. Results could be interested for researchers of thermal phenomena in building envelopes and designers of microclimate engineering systems in buildings and structures.
Keywords: air temperature, radiation temperature, stationary regime, non- stationary regime, building envelope, emergency regime, thermal inertia, inside surface layer, program, building materials
The article is devoted to the analysis of methods for obtaining light-transmitting concrete, a material that combines the strength of concrete with the ability to transmit light.It briefly reviews the history of the development of light-transmitting concrete, from the initial experiments to the modern achievements in this field. The main focus is on the composition of the material, where optical fibers are added to the traditional components, creating a transparency effect and allowing the use of concrete in the implementation of new architectural solutions. The production of light-transmitting concrete requires a special approach, including the precise distribution of fibers and their fixation in the matrix, which ensures uniform light distribution. Various methods of embedding fibers into concrete, their advantages and complexities, as well as potential directions for the development of technologies and the use of the material in construction, are discussed.
Keywords: translucent concrete, optical fiber, production technology, gypsum cement binder
The paper presents the results of a study of the effect of galvanic sludge on the basic performance properties of special-purpose ceramics. The basis of the composition of the charge is low-plastic clay, and the functional additives in its composition are boric acid and cerium oxide. Ceramics are produced by semi-dry pressing at a pressure of 15 MPa and a maximum firing temperature of 1050 ° C. It has been established that galvanic sludge decomposes into calcium and heavy metal oxides, carbon dioxide and water vapor during firing. The oxides formed during liquid-phase sintering are part of the vitreous phase, functionally modifying its characteristics. When the content of galvanic sludge in the charge is more than 5 wt. % a developed porous structure is formed in the material, which reduces its main operational characteristics. It was revealed that liquid-phase sintering provides safe immobilization of heavy metals if the content of galvanic sludge in the charge does not exceed 6 wt. %. Practical application of the charge composition, including galvanic sludge in an amount up to 5 wt. %, will increase the resistance of ceramics to high temperatures, temperature changes, acids and alkalis. The use of galvanic sludge in this area will contribute to solving the environmental problem of its processing.
Keywords: ceramics, heat resistance, chemical resistance, liquid phase sintering, galvanic sludge, low-plastic clay, cerium oxide, boric acid
Phosphogypsum is a large-scale solid waste from the production of phosphoric acid by the extraction method. The volume of accumulated waste in the world amounts to hundreds of millions of tons, and their disposal is becoming increasingly important. The article provides a brief overview of recent research on the use of phosphogypsum as a component of building materials. A list of the main factors of the negative impact of phosphogypsum waste on the environment is given, as well as the main impurities in its composition that reduce the quality of the resulting materials and methods for eliminating these impurities. It is shown that of the many products that can be obtained using phosphogypsum, the most widespread are construction and road materials, in which it is proposed to be used as a replacement for natural gypsum and sand.
Keywords: phosphogypsum, environment, building materials, road coverings, modifying additives
Expert work has been carried out to establish quality indicators for three types of concrete paving slabs: "Auriko", "Paving stone", "New City". The tests were carried out on selected samples in accordance with GOST 17608-2017. According to the test results, it was determined that only the samples of "Paving stones" tiles meet the requirements of GOST, other types of tiles revealed non-compliance of the studied samples with GOST 17608 in terms of water absorption and frost resistance.Frost resistance tests for Aurico and Novy Gorod product samples were interrupted after 15 freeze-thaw cycles due to the destruction of the samples.
Keywords: paving slabs, concrete, compressive strength, frost resistance, surface defect "sink"
The paper discusses the use of carbon fiber composite materials for reinforcement of specimens made of pipe sections in tension under the action of internal pressure. Experimental investigations of steel pipes under the action of internal pressure both without reinforcement and with different number of reinforcement layers with carbon tape are described. The main interest is in the joint operation of the pipe wall and external reinforcement elements. Significant influence of external reinforcement on stiffness and deformability of the specimens is noted.
Keywords: high-strength fiber, carbon fiber, carbon tape, adhesion layer, pipe, external reinforcement system, polymer composites, tensile strength
The article presents results of self-compacting concrete with microsilica and grinded concrete crush additive study. The work presents concrete mix designes and mechanical tests results.Found that with the use of complex additive it is possible to obtain concrete of class B80 with a strength of at least 60 MPa after 7 days of hardening under normal conditions. High frost resistance of such concrete is noted. Concluded the possibility of complex additive application and potential advantages of its usage in self-compacting concrete.
Keywords: self-compacting concrete, silica, active mineral additives, concrete crushing screening, concrete, concrete scrap, finely ground filler, secondary filler, construction waste, determination of mechanical characteristics of concrete, high-strength concrete
The paper presents the results of experiments on the production of a composite material using small-lump wood waste based on soft wood varieties and waste products from non-plasticized polyvinyl chloride. An additional component of the raw material mixture was methylene chloride, in which polymer waste was dissolved. The solution was mixed with the filler, and then the solvent was pressed and removed at its boiling point. It is established that an increase in the degree of filling of the studied material contributes to the formation of a developed porous structure. The effect of increased porosity on the main operational properties, primarily thermal conductivity and water resistance, has been revealed. It is determined that the degree of filling, equal to 55 wt. %, makes it possible to obtain a material with the most effective combination of values of basic properties for use as a building thermal insulation. The practical application of the results of the work makes it possible to produce a low-cost thermal insulation material due to the joint disposal of heterogeneous waste.
Keywords: polymer composite material, thermal insulation material, polymer waste, wood waste, polyvinyl chloride, methylene chloride
The possibility of using expanded perlite dust (RUNWAY) in cement binder systems is being considered. A method for modifying the binder by joint mechanical activation of Portland cement, alumosilicate waste and hyperplasticizer is presented. The physico-chemical features of the modified runway make it possible to regulate the processes of hydration, phase formation, as well as the formation of the structural matrix of the composite. The compressive strength of the binder using RUNWAY as an active mineral additive increases by 36% with a decrease in density.
Keywords: technogenic raw materials, perlite, binder, dispersion, modification, mechanical activation, hydration, structure formation, phase formation, resource conservation