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

A study was conducted on the development of filler compositions based on heat-treated phosphogypsum for the production of paints and varnishes with luminescent ability. In the course of the study, it was revealed that the reduced phosphogypsum, which exhibits the properties of an ultraviolet pigment, can be used to produce paints and varnishes based on colorless varnish XB-784. When using a colorless varnish and synthesized ultraviolet pigment, paint and varnish materials can be obtained that form almost transparent coatings and have a luminescent ability. The introduction of unreconstructed phosphogypsum as a filler increases the covering capacity of paint coatings. Non-reduced heat-treated phosphogypsum as a filler does not give a luminescent glow under the influence of UV irradiation, however, it increases the hiding power of the material and enhances the luminescent ability of the UV pigment.

Keywords: filler compositions, colorless varnish, ultraviolet pigments, phosphogypsum, waste recycling

This research presents the methods and conclusions obtained from modeling a composite wall panel with a wooden frame and polystyrene concrete core in the Lira-SAPR program, used in the construction of low-rise buildings for residential and commercial purposes. The findings were compared with the results of panel tests at the research laboratory of the Pacific State University (hereinafter TOGU).

Keywords: linear calculation, panel construction, low-rise construction, LIRA-SAPR, modeling

В статье представляется совершенствование технологии гидроизоляции с помощью инъектирования. Специально для этих технологий разработана полимерцементная композиция для инъекционной гидроизоляции. The article presents the improvement of waterproofing technology by injection. A polymer cement composition for injection waterproofing has been developed specifically for these technologies.

Keywords: technology, production, injection waterproofing, injection method, repair and restoration work, polymer cement composition

The physical and mechanical properties, as well as structural and rheological indices of blended compositions based on viscous oil road bitumen and three specific grades of butadiene-styrene thermoplastic elastomers (KRATON 0243, KRATON 0246, KRATON 1192) of different composition and structure are investigated. The structure and properties of initial butadiene-styrene thermoplastic elastomers are considered. The influence of the polymer modifier topology on the properties of the final blended bitumen-polymer compositions has been shown. It is established that the change of polymer composition affects the whole complex of technical, technological and operational indicators of polymer-bitumen binders. Thus, the presence of 75% diblock structures in KRATON 0243 and 55% diblock structures in KRATON 0246 significantly affect both penetration and ductility of bitumen-polymer mixtures at 0 deg. С.

Keywords: butadiene-styrene thermoplastic elastomers of various topologies, viscous petroleum road bitumen

Vulcanization is a technological process that transforms plastic rubber into rubber. As a result of vulcanization, the shape of the product is fixed, and the material becomes more durable, hard and elastic. The purpose of the article is to determine the effect of octyl phenol-formaldehyde resin on the vulcanization parameters and to identify its optimal amount for the development of vibration-absorbing materials based on butyl rubber. The effect of a vulcanizing agent (octyl phenol formaldehyde resin) on the properties of the rubber compound during vulcanization was established. As a result of the study, the kinetics of vulcanization and the effect of various components on the properties of the rubber compound, such as elongation at break, conditional tensile strength and specific damping ability, were studied. This study is conducted in order to find the optimal rubber for placement in a seismic damper used in buildings and structures.

Keywords: vulcanizing group, vibration absorbing material, butyl rubber, rubber compound, vulcanization, octyl phenol formaldehyde resin, seismic damper

The article deals with the results of research on the influence of the dosage and composition of the complex mineral additive containing chemical water treatment sludge with gaize, burnt rock or fly ash. The result of investigation is the equation for the change in shrinkage deformations over the time for mortars containing a complex mineral additive in comparison with a standard mixture without additives. There is evaluating of the influence of changes in the mortar moisture on the amount of shrinkage deformation. On the base of the research, we astablished the dependences of shrinkage deformations on the moisture content of the mortar, according to the composition and dosage of the complex mineral additive. The study revaels the influence of a complex mineral additive on shrinkage deformations. The equation has been obtained that describes the change in shrinkage deformations depending on the relative humidity and it has been shown that the tested mortars with a rational composition and dosage of a complex mineral additive with an average air humidity of the driest month in Rostov-on-Don of 47% will not exceed 0.55 mm/m . Shrinkage deformation with the ratio of the complex additive with fly ash or burnt rock 20-30% are 0.42-0.79 relative to the additive-free standard.

Keywords: dry construction mixture, shrinkage, mineral additive, mortar, chemical water treatment sludge, burnt rock, fly ash

The article is devoted to the study of the main methods of ice crossings and their reinforcement. Key concepts related to this type of transportation are considered, including the definition of an ice crossing, its role in the transportation infrastructure, and the conditions necessary for its construction. Special attention is paid to the preparatory work carried out in summer and the main work carried out in winter. The methods of ice crossing reinforcement are described in detail, including thermal reinforcement, use of logs, snow reinforcement and use of geosynthetic materials. The advantages and disadvantages of each method are discussed, as well as factors influencing the choice of a particular reinforcement method.

Keywords: ice crossing, reinforcement

The article discusses the use of simplex methods of experiment planning to determine the optimal composition of composite building materials. Composite building materials are multicomponent systems, so their properties depend on a large number of factors that are diverse in nature and influence. The use of orthogonal plans is not able to adequately describe experimental data with a wide range of varying factors. Therefore, the article proposes to use simplex-lattice Scheffe's plans. A complete third-order model was developed to determine the optimal composition of the filled cement composite, and a regression equation was written. The adequacy of the equation was confirmed at the control points of the plan using the Student's criterion. The proposed planning method can be used to optimize the composition of multicomponent systems.

Keywords: multicomponent system, optimization methods, composite building material, experiment planning, simplex plans, Scheffe's polynomial, regression equation

This paper presents the results of experimental studies on the development of a chemical additive for concrete and mortar mixtures to establish a modifying effect. A chemical additive was developed - a multifunctional cleaning agent - “LOC”, in order to establish its modifying effect for concrete composites. The results of the experimental studies confirm the effectiveness of the chemical additive under study as a modifier. Composite material samples modified with the developed product show higher technical characteristics: the obtained BC samples correspond to the concrete grade for workability - P3, when the standard sample has a grade - P2, the compressive strength of the control BC samples, with a chemical additive - ""LOC"" in an amount of 1%, increases by 28%, the established optimal dose of the additive being developed - Ministry of Emergency Situations - “LOC” for Bx and mortar mixtures is 1%, which guarantees its economic efficiency.

Keywords: concrete composite, modification, surfactants, cleaning agent – “LOC”, anionic and nonionic surfactants, modifier, development, chemical additive, plasticity, strength, water absorption

The article examines the application of the method of mathematical planning of an optimal experiment in determining the strength characteristics of reinforced soils. For the analysis, a multicomponent soil system was studied, consisting of unsalted and saline soils reinforced with bitumen with cement additives and surfactants. During the planning of the experiment, factors affecting the strength characteristics and their levels, as well as the intervals of variation of factors, were determined. As a result of solving the problem, mathematical models of adhesion and angle of internal friction of reinforced soils were obtained. Based on the obtained regression equations, the main conclusions were drawn.

Keywords: stabilized soils, complex soil strengthening, experiment planning, complete factor experiment, mathematical model, regression equation