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Systemic-ecological symbiosis model: integrating secondary resources into construction materials to enhance the environmental safety of machine-building enterprises

https://doi.org/10.58224/2618-7183-2025-8-5-1
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Аннотация
The research addresses the integration of secondary resources from machine-building enterprises into construction composites as a pathway to reduce clinker consumption, lower the carbon footprint, and improve industrial sustainability. A symbiotic model was developed that links a machine-building plant as a donor of metallurgical, glass, and polymer by-products with construction material production as a recipient. The model operates on weekly “generation–utilization–storage” balances for production lots of 10 m³ and is optimized under three groups of constraints: economic (cost minimization), environmental (CO₂ intensity reduction), and technical (compressive strength, water absorption, and chloride permeability by RCPT). A multi-objective optimization scheme using ε-constraint methods was applied together with regression-based property models and stochastic simulations (Monte Carlo and bootstrap). The analysis demonstrates that partial clinker substitution with up to 50% ground granulated blast-furnace slag and up to 20% recycled glass achieves a 40–45% reduction in unit CO₂ emissions, while maintaining 28-day strength above 40 MPa and RCPT values within 2,000–3,000 C (Coulombs). The Pareto front highlights an equilibrium zone of 55–60% CO₂ and 84–87% relative cost as a rational compromise between environmental and economic performance. Statistical verification confirms the robustness of the solutions with failure probability Pf < 10%. Practical implications include the ability to design low-carbon mixtures with predictable durability, integrate secondary resource flows into construction supply chains with ≥95% utilization efficiency (and >97% for glass/ash streams), and reduce regulatory and environmental risks. The framework provides machine-building and construction industries with a reproducible methodology to scale decarbonization strategies while ensuring infrastructure reliability.
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Experience of concreting a massive monolithic foundation slab

https://doi.org/10.58224/2618-7183-2025-8-5-2
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Аннотация
The large number of recipe and technological factors affecting the stress-strain state of concrete in the initial period of massive monolithic structures erection predetermines the expediency of using modeling of temperature fields and stresses with software packages based on analytical and numerical solutions when developing technological regulations for concreting. Improving the algorithm for calculating temperature fields and stresses taking into account the kinetics of concrete heat release, heat exchange conditions, ambient temperature and the stages of construction of structures is a pressing task. A comparison was made of calculated, laboratory and natural values of some parameters when concreting a foundation slab with a volume of 1642 m3, a surface area of 821 m2, and a thickness of 2 m. Concreting was completed in 13.5 hours with an average intensity of concrete mix placement of 122 m3/h, and a peak intensity of up to 240 m3/h. A method for calculating temperature fields and stresses taking into account the staged nature of construction has been developed in the MATLAB environment. It does not require rebuilding the geometry of the finite element model, adding nodes and elements during the process of laying new layers, and allows for the correct consideration of the dependence of the strength and deformation properties of concrete on the degree of its maturity. The results of calculated and measured temperature values excluding heating from solar radiation showed a discrepancy of up to 10 °C on the upper surface at some points in time. Some discrepancy between the calculated and experimental values of stresses and deformations with a qualitative coincidence in the nature of the curves is due to the neglection of shrinkage and rapid creep of concrete and poor study of the deformation properties of concrete with additives based on polycarboxylate esters at an early age.
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Effect of substrates on the photocatalytic activity of the composite coating fabricated by detonation sprayed Ti powders

https://doi.org/10.58224/2618-7183-2025-8-5-3
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Аннотация
Composite coatings based on titanium oxides were successfully deposited on fine-grained concrete and porcelain tile substrates using a robotic complex for detonation spraying. The study focused on the influence of substrate roughness and composition on the microstructure, phase composition, and photocatalytic properties of the coatings. Dense, uniform coatings with a bimodal lamellar microstructure and thicknesses ranging from 20–30 µm on concrete to 250–300 µm on porcelain tiles were obtained without cracks or significant porosity. It was observed that the phase composition of the coatings, which included a mixture of titanium, anatase, rutile, TiO, and Ti₂O₃ phases, remained unaffected by variations in the substrate composition. Regardless of the substrate material used, all coatings exhibited similar phase constituents. However, the surface roughness of the substrates played a crucial role in determining the microstructure and photocatalytic performance. The rougher concrete surface promoted a higher anatase content, resulting in enhanced photocatalytic activity compared to coatings on smoother porcelain tiles. Coating thickness and porosity did not significantly affect photocatalytic efficiency. Additionally, the kinetic constants of the obtained coatings exceeded those of commercial sol-gel coatings and aligned with values typical for thermally sprayed coatings. The obtained results indicate that composite titanium oxide coatings demonstrate high potential for industrial applications where effective breakdown of organic pollutants on diverse surfaces is required.
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Wall materials based on low-grade loams and industrial waste

https://doi.org/10.58224/2618-7183-2025-8-5-4
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Аннотация
Clay raw materials used in Kyrgyzstan for the ceramic industry characterized as low-plasticity , highly sensitive and saline. In addition, the high content of carbonates in loams leads to the production of low-quality bricks. In order to obtain ceramic bricks with high-quality performance characteristics, it is necessary to use innovative approaches in the preparation of clay raw materials.
The raw used materials were local loess-like loams from the Orok deposit and ash from the Bishkek thermal power plant and a surfactant – sodium naphthenate. The loam and ash subjected to mechanochemical activation by joint grinding in activator-mixer and adding sodium naphthenate together with mixing water. The dried cylindrical samples fired in the temperature range of 900, 950 and 1000 0 C.
The results of the studies showed that mechanochemical activation of ash-clay raw materials increases the plasticity of the clay-ash mass by 140 %, while reducing the molding moisture and sensitivity coefficient.
The sintering process is intensified: at a firing temperature of 950 0C and 60 % ash, it is possible to obtain a shard with a density of 1.57 g/cm3 and water absorption of 17 %. The compressive strength is 16.3 MPa.
Amorphization and destruction of raw material particles contribute to an increase in the glass phase content. As a result, open pores are tightened, forming a strong monolithic structure.
The obtained samples based on mechanochemical activation with the addition of 60 % ash have the M150 grade and frost resistance of F 25.
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Formation of organizational and technological solutions for major repairs of healthcare facilities

https://doi.org/10.58224/2618-7183-2025-8-5-5
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Аннотация
Major repairs of healthcare facilities can repurpose a building, increase its capacity, improve in-frastructure needed to accommodate advanced medical equipment and to ensure compliance with updated regulations and modern standards. The capital renovation of healthcare facilities constitutes a complex engineering and organiza-tional system characterized by: the multifactorial nature of technological processes, the necessity for adaptive management under regulatory constraints, stringent coordination requirements among project stakeholders. Such projects are characterized by the involvement of a large number of stakeholders pursuing versatile goals and having dif-ferent levels of knowledge in the field of construction. These factors disrupt coordination and project management. The purpose of the study is to analyze process control and engineering so-lutions made in the course of major repairs of healthcare facilities, to assess factors affecting their effectiveness, and to develop recommendations to improve these solutions. This study has developed an innovative systematic planning methodology for capital renovation of healthcare facilities, grounded in principles of preventive risk management. Implementation of this approach demonstrated statistically significant improvements across key performance indicators: a 10-15% reduction in project timelines, enhanced compliance with quality standards, and an 15-18% increase in labor productivity.
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Strength gain kinetics of cements manufactured using fluorgypsum waste

https://doi.org/10.58224/2618-7183-2025-8-5-6
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Аннотация
The study is devoted to assessing the possibility of replacing natural gypsum-anhydrite stone with man-made fluorogypsum waste (gypsum dihydrate and anhydrite) as a calcium sulfate additive in the production of Portland cement in compliance with environmental standards. It was found that such a replacement is technically feasible, but requires taking into account the specifics of the waste: when anhydrite is heated in the range of 320–450°C, hydrogen fluoride is released, which emphasizes the need to control the temperature conditions of processing. The kinetics of strength gain of cement-sand samples manufactured according to GOST 30744-2001 is successfully described using the Avrami-Erofeev equation (the proportion of explained variance ≥0.99). It is shown that the composition with fluorogypsum dihydrate slows down the growth of strength at the early stages of hardening, while the addition of anhydrite increases it in the initial period. This is due to the slow release of sulfate ions (SO₄²⁻) from anhydrite, which suppresses the premature formation of ettringite and stimulates the hydration of silicate phases. Replacing natural gypsum with technogenic gypsum increases the setting time of cement and causes a slight decrease in compressive and flexural strength due to differences in the kinetics of new formations and the hydraulic activity of technogenic components. The results confirm the technological feasibility of using fluorogypsum waste in the cement industry. The work contributes to solving the problem of recycling technogenic waste and reducing resource costs in the construction industry.
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Dust concentration in the air of roadside areas

https://doi.org/10.58224/2618-7183-2025-8-5-7
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Аннотация
The article addresses a pressing issue – air pollution in cities with fine dust particles. This study collected 18 dust samples during spring and autumn periods in various parts of Elista city. Based on the analysis results of the selected dust’s dispersed composition, regression equations were developed, where the dependent variable was the concentration of PM10 and PM2.5, and the independent variables were the distance from the sampling site to the highway and the height of the sampling site from the ground. Samples were collected from window sills and other horizontal surfaces where dust settled from atmospheric air. Thus, the study aimed to critically analyze the patterns of dust composition changes in the air influenced by various factors, excluding the impact of industrial production, which is not widespread in this city. Empirical dependencies of fine dust concentrations of PM10 and PM2.5 fractions on the distance from the road and the height of the sampling site were obtained. A general range of values was obtained for the dust mass distribution function by particle diameters during spring and autumn. The study found that the geometry of the building, its relative position to seasonal winds, and the distance from the road play a much more significant role in the dispersed composition than wind speed, humidity level, or season
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Utilization of serpentinite waste for the production of magnesium compounds

https://doi.org/10.58224/2618-7183-2025-8-5-8
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Аннотация
The article presents the results of research on the complex processing of powdered man-made serpentinite waste formed during the enrichment of chrysotile raw materials in order to obtain high-purity magnesium compounds and assess the potential of their use in the production of building materials. The relevance of the work is due to the need to dispose of accumulated waste and expand the raw material base for the construction industry within the framework of the principles of circular economy. The developed technology includes the stages of acidic leaching of magnesium from PTW with sulfuric acid, neutralization and purification of the solution using thermally activated PTW (TA-PTW) and subsequent precipitation of the target products. It was found that thermal activation of waste at 750 °C leads to dehydroxylation and the formation of highly reactive phases, forsterite and periclase, which significantly increases their sorption activity. The optimal leaching regime is recognized as the use of 0.7 stoichiometrically normal amount of H₂so₄, which makes it possible to extract 82.5% of magnesium from the amount of acid introduced into the solution. The combined use of the initial and thermally activated PTW provides a degree of magnesium extraction of 52.3% of its total content in the system and effective purification of the magnesium sulfate solution from impurities of iron, aluminum, chromium and nickel. Sequential precipitation from the purified solution made it possible to obtain high–purity magnesium hydroxide with a calcium content of 0.0110%, and its subsequent calcination - magnesium oxide with a calcium content of 0.0187%. Special attention is paid to the prospects of practical application of synthesized compounds in the construction industry. It is shown that magnesium sulfate can be used as a modifying additive in cements and as a sealer for magnesia binders. Magnesium hydroxide is an effective flame retardant filler, and magnesium oxide is the main component for the production of flame–resistant and moisture-resistant magnesia binders and plates such as glass-magnesium sheets. Thus, the work demonstrates not only the technical feasibility of highly efficient processing of serpentinite waste, but also the significant resource potential of the resulting magnesium compounds for creating modern building materials with improved performance characteristics.
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Involvement of concrete internal potential to reduce portland cement consumption and ensure sustainable development

https://doi.org/10.58224/2618-7183-2025-8-5-9
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Аннотация
Protection of artificial human habitat from negative impacts of external environment and extension of service life of building structures become priority tasks of structural concrete improvement. The most important vector of development is the increase of their strength due to involvement of the internal resources with minimal use of additional external ones, which corresponds to the sustainable development concept. However, practice shows that now application of high-strength concretes, which are the main focus of researchers, is very limited due to insufficient development of production infrastructure, regulatory documentation, design and construction methods, economic and other reasons.
At the same time, approximation to requirements, according to the sustainable development concept, for the most widely used concretes with grade strength classes (B20-B50) is required right now. In this regard, the idea of application of the most important principles of obtaining high-strength self-compacting concretes in the manufacture of medium strength material is relevant. The article presents the main stages of research on development of the design methodology of medium strength classes self-compacting concretes with reduced Portland cement consumption.
The methodological basis for designing these concretes is the successive introduction of additional components principle while recording their effect on the material properties. The use of ground quartz sand as a mineral additive is due to the concrete mix stability requirements and its widespread availability, which allows for the practical application of the obtained results with minimal barriers and contributes to the reduction of CO2 emissions. It has been established that when selecting sand fineness of 180...220 m2/kg and a fixed amount of active mineral additive (7.5%), the compressive strength of the cement paste can be reduced to the following linear dependence: Rbinder28 = 118.9 – 0.22CM. Rational contents of fine and coarse aggregates have been identified, and their quantitative effect on the strength of the resulting concrete has been established. It has been established that the obtained concretes with increased efficiency of Portland cement using can be used in practice in various construction areas, and are also necessary for the search and transparent monitoring of the influence of others, more reactive mineral additives based on industrial products and rocks.
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Application of multi-criteria evaluation methods to create urban development opportunities within the concept of sustainable architecture of buildings and urban areas

https://doi.org/10.58224/2618-7183-2025-8-5-10
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Аннотация
The advancement of urban development has made it possible to improve the quality of infrastructure and the organization of urban territories, affecting cities’ competitiveness and investment attractiveness. The study aims to apply multi-criteria evaluation methods to create urban development opportunities in the sustainable architecture of buildings and urban areas. The primary data collection methods include document analysis and an expert survey. Through document analysis, the authors identify the basic methods of evaluating buildings and architectural objects to establish compliance with the requirements of sustainable architecture. The expert survey results highlight the most dynamically developing and globally recognized methods: LEED and BREEAM. Further analysis sheds light on the specific features of criteria-based evaluation of buildings under LEED and BREEAM certification, compares the lists of building evaluation criteria in BREEAM and LEED, and considers the practical implementation of LEED and BREEAM building certification while highlighting and describing architectural objects. The authors conclude that the standards defined in the BREEAM and LEED multi-criteria methods exhaustively conform to the principles of sustainable architecture, encompassing environmental, economic, and social conditions. BREEAM and LEED can be applied to new and modernized residential and public buildings.
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