Одеська державна академія будівництва та архітектури
TECHNOLOGY OF EDUCATIONAL INSTITUTIONS’ RECONSTRUCTION AFTER DESTRUCTION CAUSED BY ARMED CONFLICT ON THE TERRITORY OF UKRAINE RIGIDITY
The article is of a review nature and is devoted to the analysis of modern trends in technologies for the restoration of secondary education institutions after destruction as a result of the armed conflict in Ukraine. It substantiates the urgent need to develop a new, forward-looking model for restoring educational infrastructure, grounded in the principles of energy efficiency, technological innovation, resilience, and elevated safety standards. In the context of post-war recovery, education is recognized as a critical pillar for societal stability and sustainable development, making the reconstruction of schools a strategic priority for the country. The study includes a thorough analysis of the existing regulatory and legal framework that governs reconstruction efforts. Key stages of the construction and design cycle are outlined, such as structural assessment of damaged buildings, development of project and technical documentation, coordination of civil protection strategies, and implementation of construction and installation activities. Special focus is placed on the engineering and architectural aspects of building safe and resilient educational spaces capable of withstanding future threats. Furthermore, the article explores the integration of protective infrastructure, such as reinforced shelters, early warning systems, and optimized evacuation paths, into school design. Beyond physical protection, the study emphasizes the psychological and emotional well-being of students and educators. This includes the adoption of human-centered architectural approaches, inclusive spatial planning, and flexible, adaptive design that meets the diverse needs of school communities. A comprehensive reconstruction model is proposed, incorporating innovative building technologies, resource-efficient and sustainable materials, and a strategic methodology tailored to post-conflict conditions. This integrated approach aims to create durable, functionally advanced, and socially safe educational environments that respond to both current challenges and future demands.
Technology and organization of construction production
Copyright (c) 2025 MODERN CONSTRUCTION AND ARCHITECTURE https://creativecommons.org/licenses/by/4.0
AIR DISTRIBUTION EFFICIENCY WITH A LINEAR SLOT DIFFUSER IN NON-ISOTHERMAL CONDITIONS
Effective provision of a comfortable indoor climate is a key requirement for modern central air ventilation systems. These systems play an important role in creating a healthy and comfortable environment for living, working or relaxing. Taking into account modern architectural trends and design solutions, linear louver diffusers are becoming increasingly popular as air distribution devices. Their aesthetic appeal allows them to be harmoniously integrated into interior design, often making them central elements that emphasize the style of the room. The design feature of linear louver diffusers lies in their specific structure: they have a small width with a significant length, which distinguishes them from traditional compact diffusers of round or square shape. This feature significantly affects the characteristics of the air jet formed by such diffusers. During the operation of ventilation systems in air conditioning or air heating modes, linear diffusers create unique air flows that differ from compact jets in their behavior, velocity and temperature distribution. These differences must be taken into account at the stages of design, adjustment and operation of ventilation systems in order to ensure their effective operation and achieve an optimal microclimate. Data obtained from computer modeling and experimental studies play a key role in the development and optimization of ventilation systems with linear louver diffusers. Modeling allows you to predict the behavior of air flows in different conditions, taking into account the geometry of the room, the location of the diffusers and air parameters (temperature, humidity, flow rate). Experimental studies, in turn, confirm theoretical calculations and allow you to refine the parameters of the system. Thanks to an integrated approach that combines modeling and experiments, it is possible to achieve high efficiency of ventilation systems, minimize energy consumption and ensure a comfortable microclimate in the premises. The use of linear louver diffusers also contributes to reducing noise exposure and uniform air distribution, which is especially important for residential and public spaces. Proper selection and adjustment of such diffusers allows you to avoid areas of air stagnation or excessive turbulence, which can negatively affect the comfort of users. Thus, taking into account the features of linear diffusers at all stages ‒ from design to operation ‒ is the key to creating effective and aesthetically attractive ventilation systems that meet modern requirements for comfort and energy efficiency.
FORMATION OF CEMENT STONE MICROSTRUCTURE IN THE PRESENCE OF COMPLEX CHEMICAL ADMIXTURES
This article experimentally investigates the possibilities of technological regulation of cement stone and concrete microstructure parameters through the introduction of chemical admixtures of various natures. Based on studies concerning the influence of chemical admixtures on cement hydration processes and cement stone microstructure, a comparative evaluation of the hardening and pore formation of cement stone with accelerating, plasticizing, and complex admixtures was performed. Specifically, the study focused on the impact of complex chemical admixtures, including a superplasticizer like С-3 (likely a naphthalene sulfonate-based type) and LST (lignosulfonate) combined with accelerators such as NaCl or KCl, Na2CO3, K2CO3, Na2SO4, K2SO4 on the pore formation characteristics during the hardening of two types of cement: Portland cement PC CEM I 42.5R and slag Portland cement SPC CEM II B-S 32.5 R. These cements differ in their mineral composition, slag content, and consequently, their hydration rate and structure formation. It was established that cement stone, whose porosity is characterized by a minimal pore radius and an optimal ratio between the volumes of gel pores and capillary pores, can be achieved through the complex application of an accelerator and a plasticizer. The synergistic effect of the superplasticizer reducing the water-cement ratio and improving particle dispersion, alongside the chloride accelerator speeding up early hydration, contributes to this refined pore structure. Furthermore, a novel approach for evaluating the effectiveness of modifying the cement stone structure is proposed using the coefficient Kef, defined as the ratio between the volumes of gel pores and capillary pores (ratio of dynamic microstructural indices). This quantitative information regarding the cement stone's microstructure and the limits of its regulation under the influence of internal and external factors allowed for the formulation of a concept regarding the possibilities of achieving specified concrete properties by modifying the corresponding parameters of the cement stone's microporosity.
AN ANALYTICAL METHOD FOR THE ANALYSIS OF FUNCTIONALLY GRADED BEAMS RESTING ON A WINKLER ELASTIC FOUNDATION
This publication addresses the analysis of so-called functionally graded beams (FGBs), whose material properties vary along their length according to a specified gradient. The study is devoted to the development of an analytical method (AM) for bending analysis of such beams resting on a homogeneous, continuous Winkler elastic foundation. The material's modulus of elasticity and the external load are assumed to be arbitrary, continuously varying functions dependent on the coordinate of the beam’s neutral axis. The proposed method is based on an exact solution to the corresponding fourth-order ordinary differential equation of bending with variable coefficients. The unknown integration constants are expressed in terms of initial parameters, which are determined by applying the prescribed boundary conditions. The fundamental functions and the particular solution of the differential equation are represented as power series in a dimensionless parameter, with variable coefficients obtained through recursive integral relations. For practical convenience, the fundamental functions and the particular solution are transformed into power series format. This reduces the bending analysis of FGBs to a numerical implementation of explicit analytical expressions for stress-strain state parameters. A numerical example demonstrates the practical application of the AM. A prismatic FGB with a parabolically varying modulus of elasticity is considered. The AM results are presented in both numerical and graphical formats for the case where the left end of the beam is simply supported and the right end is fixed. The obtained numerical values are treated as exact, since the analysis is based on an exact solution of the governing differential equation. The availability of such a method enables the assessment of the accuracy of solutions obtained using various approximate methods. For verification purposes, corresponding solutions obtained by the Finite Element Method (FEM) using the LIRA-SAPR software are also provided. The comparison confirms the validity of the proposed analytical method.
RESEARCH ON THE RESISTANCE OF VENTILATED RAINSCREEN FACADES TO DYNAMIC AND VIBRATIONAL LOADS
The study aims to determine the stability of KMD VF ventilated facades, featuring RONSON 250×65×22 Busum facade tiles, when subjected to vibrational and dynamic influences. A key objective is to assess their applicability in seismically active regions of Ukraine. To achieve this, both computational analyses of the stress-strain state of the facade system elements and experimental laboratory tests on a fragment of the system were conducted. The research methodology involved a comprehensive literature review and analysis of existing technical documentation. An experimental procedure was developed for testing on a vibration stand, utilizing a Vibran-2.0 vibro-analyzer and a universal strain gauge station. A facade system fragment measuring 1000×900 mm was subjected to controlled vibrational loads. Concurrently, a numerical model of the fragment was developed and analyzed using the Lira-SAPR software. The computational results were then rigorously compared with the experimental data, confirming the adequacy of the calculation scheme with an error not exceeding 7%. Furthermore, a detailed calculation of the facade system's response to seismic loads was performed for a hypothetical 36-meter high-rise building situated in a 9-point seismic zone, in accordance with DBN В.1.1-12:2014. The spectral method was employed, and the computational model utilized volumetric finite elements for the building and clinker, shell elements for brackets and purlins, and special finite elements for modeling connections between clinker-purlins, purlins-brackets, and brackets-building. The experimental tests demonstrated the facade system's resilience and integrity. No individual tiles detached, and the connection nodes remained reliable, even under load levels corresponding to approximately 60% of a 9-point seismic event. The seismic load calculations further corroborated these findings, indicating that the overall bearing capacity utilization of the system did not exceed 65%, thereby maintaining a substantial 35% safety margin. Crucially, the protection against the fall of individual tiles was ensured with a significant 57% margin. Based on the comprehensive results obtained from both experimental and computational investigations, it is concluded that the use of KMD VF ventilated facades, adorned with RONSON 250×65×22 Busum facade tiles, is feasible and recommended for construction projects located in seismically hazardous regions of Ukraine.
SEISMIC RESISTANCE OF LARGE-PANEL BUILDINGS IN SEISMIC REGIONS. RETROSPECTIVE ANALYSIS OF REGULATORY FRAMEWORK
The article presents an extensive retrospective analysis of the regulatory framework governing seismic-resistant design of large-panel buildings in seismic regions of Ukraine, spanning from early Soviet documents (PSP-101-51, SN 8-57) and subsequent SNiP regulations (II-A.12-62, II-12-69, II-7-81) to contemporary DBN V.1.1-12:2006 and DBN V.1.1-12:2014. The study's relevance stems from increased design seismic intensity in numerous regions following the implementation of ZSR-2004 maps, which necessitated reassessment of seismic resistance in buildings previously constructed without appropriate anti-seismic measures. The authors systematized key regulatory criteria (maximum building height and length, minimum requirements for joints and reinforcement, calculation methods) in a comparative table to demonstrate the trends of increasing requirements and transition from general recommendations to precise numerical limitations. A comprehensive, structured approach was applied, including documentary research, thematic analysis, and systematic grouping of regulatory requirements, which enabled establishing the relationship between the construction period of a large-panel building and its degree of compliance with current standards. The study demonstrates that the development of requirements has occurred in response to accumulated experience, technological advances, and international influences, resulting in modern calculation methods (spectral, nonlinear), detailed specifications for joints and reinforcement, and possibilities for seismic isolation implementation. The obtained results provide opportunities for direct integration into the methodology of visual assessment and certification of existing residential buildings, significantly optimizing the process of identifying potentially problematic structural elements and facilitating the development of scientifically substantiated solutions for strengthening load-bearing structures by engineers. Thus, the retrospective approach serves as a valuable tool for improving the efficiency of seismic resistance assessment, optimizing resources for building reinforcement, and enhancing regulatory documents in the field of seismic-resistant construction.
LIGHTWEIGHT PLYWOOD PANELS WITH CURVED X-SHAPED LONGITUDINAL RIBS OF RIGIDITY
The current state of the construction industry in Ukraine increases every year the percentage of buildings implemented using wood in new construction, picking up the trend of European countries, where wood is becoming the main material in the implementation of residential and public buildings. The number of floors of such timber frames already reaches 20-30 floors with load-bearing frame structures made of glued-laminated timber and CLT panels. The latter are a new innovative panel-type material that allows assembling buildings of various thicknesses easily and quickly, but their efficiency is significantly reduced for spans of more than 6 m. The proposed plywood lightweight panels or PRX panels are a solution to the problem of simple covering for increased spans of coverings and floors due to an innovative approach using bent longitudinal ribs of panels for stability of which the arrangement of transverse ribs is not required. The problem of this type of panels consists in determining the compliance of X-shaped plywood ribs based on research with the development of a simplified calculation method as a system of factors or coefficients correcting traditional algorithms for calculating similar thin-webbed structures operating in bending. In the proposed development of lightweight and simultaneously rigid panels, the main emphasis was placed on the simplicity and manufacturability of panel production, relying on modern automated production equipment. PRX panels can be used as elements of self-supporting walls. The purpose of developing innovative lightweight plywood panels was to create a new technological solution for ceilings and roofs of buildings for spans of 7-20 m. The idea of lightweight and rigid panels with X-shaped curved webs or ribs is a continuation of research on beams with such walls, where the efficiency of the curved shape of plywood walls showed certain advantages compared to classic I-beams with plywood webs. The proposed solution of the covering panels allows assembling buildings for various purposes and place insulation and some communications inside the panels quickly. To clarify the parameters of strength, deformability and determine the nature of panel failures, full-scale static tests of a full-scale sample were conducted, as well as numerical studies were performed in analytical software packages with a focus on the behavior and compliance of curved plywood walls at different stages of panel loading. Based on the experimental and numerical data obtained, a methodology was proposed that takes into account not only the geometry of the cross-section, but also its sweating of plywood walls or longitudinal ribs of PRX panels.
NONLINEAR MODELING OF SUPPORTING PERFORATED BEAMS ON COLUMN HEADS
The possibility of using the LIRA-FEM software package for nonlinear modeling of the actual design scheme and actual operation of an I-beam continuous perforated beam at the point of its support on the horizontal column head plate is considered. The finite element library allows modelling the operation of various types of structures with elements of various configurations, as well as use special elements for modeling joints in nodal connections. Nonlinear calculation allows modeling the actual operation of the structure, which takes into account the actual support of the beam on the column; fastening the beam to the column head with bolts; a pre-applied bolt tension force, and a given diagram of the steel operation under static loading. A method for nonlinear calculation of the beam-column system has been developed and the modeling stages are presented, starting with the creation of a new problem and ending with an extended analysis of the results obtained in the design sections and points of the structures. The modeling of the joint operation of a beam with a column is considered in detail, taking into account the real operation of bolts in the connections, depending on their pre-tensioning forces. A task has been formulated for performing nonlinear calculation of perforated metal double-span continuous beams taking into account plastic deformation of the material, which aims to determine the ultimate load and the nature of the loss of stability. In problems of physical and geometric nonlinearity, calculations are performed using iterative and stepwise methods. Nonlinear load modeling was performed, which is an advanced level of structural analysis that allows taking into account the physical or geometric nonlinearity of the behavior of the material or shape of the structure under the action of significant loads. In linear loading, it is assumed that the load is applied gradually and the material responds proportionally. In nonlinear analysis, the material can change its stiffness under the action of the load, plastic deformation occurs in it, and material failure can also be taken into account.
ELEMENTS OF NATURE-INTEGRATED ARCHITECTURE ‒ RECREATIONAL AREAS ON THE ROOFS USING THE RECUPERATIVE HEAT OF VENTILATION SYSTEMS
The issues of organizing recreation areas at the district level for large and largest cities were studied. These recreation areas are one of the primary tasks in the current conditions of physical and psychological stress on the population of cities. At present, the population of most Ukrainian cities has grown sufficiently, and the number of recreation areas, especially local (district-type) ones, has remained virtually unchanged. Based on the analysis of architectural and architectural-planning solutions of modern urban development, it is proposed to use the roofs of high-rise buildings for such areas, for which purpose they should be landscaped. Recreational areas on exploited roofs as an element of nature-integrated architecture are considered. The issue of exploitation of flat roofs, their use as recreational areas, gardens with shrubs or even trees, gazebos, recreation areas, greenhouses or winter gardens is investigated. To create high-quality conditions for plant growth on roofs and create green areas (winter gardens, greenhouses, greenhouses, etc.), it was proposed to use the low-potential heat of ventilation emissions. For this purpose, the use of both the heat of ventilation emissions directly (for heating the soil) and the use of systems with an intermediate heat carrier, for example, with heat pipes for heating, for example, water for plant irrigation, was considered. Some problems of utilization of low-potential heat in systems with natural exhaust air movement are considered. Ways to solve urgent problems in this direction are identified. To increase the temperature potential of ventilation emissions, the possibility of using emissions from the kitchen area and the area of sanitary facilities, the use of heat pumps is proposed, which can increase the thermal potential of ventilation emissions. An installation scheme for increasing the temperature potential of ventilation emissions is proposed. Its advantages and disadvantages are considered.
AUTHENTICITY 30 YEARS LATER IN THE CONTEXT OF THE 1994 NARA CONFERENCE
The Ukrainian experience of architectural heritage losses caused by war raises a fundamental question for the professional community: what exactly should be preserved when reconstructing destroyed heritage – the material, the image, the function, or the meaning? In this context, the concept of authenticity becomes critical, going beyond a purely theoretical category and turning into an essential decision-making tool in restoration, reconstruction, and reproduction. The aim of the study is to determine whether the Nara Document represented a paradigmatic shift in attitudes toward heritage or merely formalized an already existing plurality of interpretations. Methodologically, the research relies on contextual, discursive, and comparative analysis, as well as a meta-analysis of Michael S. Falser’s text, which reconstructs the main vectors of debate at the Nara Conference. The focus is on current challenges, analysed through materials from the 2024 conferences in Thessaloniki and Tokyo, where the tension between flexibility and the need for methodological clarity was highlighted, against the backdrop of the continued absence of a single internationally recognised methodology for assessing authenticity. The article explores how authenticity operates not only in normative documents but also in decision-making practices, the formation of local policies, and institutional procedures that directly affect the fate of heritage sites. It is concluded that the Nara Document did not provide a fixed definition of authenticity but changed its philosophical framework: authenticity is now understood as the result of dialogue between cultures, practices, and communities – a dialogue that requires not only remembering but also rethinking in the face of contemporary challenges, ethical responsibility, and the transformative potential of heritage.
COVERAGE FEATURES OF THE MULTIFUNCTIONAL PUBLIC BUILDINGS FORMATION PROBLEMS IN DOMESTIC SCIENTIFIC SOURCES: COMMUNICATION AND FUNCTIONAL ASPECTS
The subject of multifunctional public buildings has been extensively explored within the field of domestic science. A wide range of works have been dedicated to this subject, including abstracts presented at scientific conferences, research conducted for dissertations, and monographs. The material that has been accumulated thus far makes it possible to speak of the existence of a certain school of thought on the multifunctionality of public structures. Its primary characteristics are a combination of communicative and functional aspects that dialectically connect this issue with the tradition of modernism, and on the other hand, with the peculiarities of the information age. This specificity should be considered a strong point of the national discourse on multifunctionality, and its further practical continuation may lead to positive results. The distinction between communicative and functional aspects is not exclusive for the purposes of this article, as they often exist not only in close interaction with each other, but also in the context of a more complex system of design situations and solutions that are associated with different scales of coverage (the level of the individual, building or urban fabric), as well as with certain priorities of providing space with symbolic and supra-functional qualities. The latter are related to the concepts of lifestyle and positioning oneself in a positive life situation by those who are direct participants in the space – involved in it both intentionally and accidentally. These three areas are equally integrated into both the communicative and functional concepts of multifunctionality of public buildings and together create a complex structure of the subject area of theoretical coverage of this topic. The proposed system of knowledge distribution, however, is not only an intellectual reflection, but also the basis for creating a set of practical recommendations for further improving design practices, as well as creating our own identity of multifunctionality in architecture. The novelty of the material presented in the article is related to the fact that the future development of design thinking in the field of multifunctionality of buildings and spaces is predictably associated with the search and development of various formats for combining and interacting with communicativeness and functionality, as well as expanding their semantic and technological content.
FACTORS IN THE FORMATION OF RESIDENTIAL DISTRICTS IN KHARKIV: A HISTORICAL AND SPATIAL ANALYSIS OF THE 17TH–18TH CENTURIES
This article presents a historical and spatial analysis of the formation of residential districts in the city of Kharkiv, with a focus on the earliest stages of urban development. The study explores two key periods in the city’s evolution: its founding as a Cossack fortress and its transformation into a Sloboda town. Rather than providing a full historical overview of Kharkiv’s urban history, the research concentrates on the foundational phases of its residential spatial structure. The introduction outlines the unique context of Kharkiv’s growth, characterized by the combination of spontaneous settlement, adaptation to natural terrain, and shifts in city-forming functions. A significant proportion of the city’s area remains occupied by low-rise private housing‒tracing its origins to the Sloboda settlements of the 17th–18th centuries ‒ which now faces challenges related to integration into the contemporary urban fabric. The research emphasizes the spatial conflicts that emerge at the interface between these historically formed districts and modern high-density development, which underscores the need for nuanced urban planning strategies. The study aims to identify the core principles behind the formation of Kharkiv’s residential areas and understand how natural conditions, military and administrative logics, and social stratification influenced spatial patterns. It employs an interdisciplinary methodology, combining architectural history, urban planning, cartographic analysis, and socio-geographic approaches. Historical maps, general plans, archival records, and previous academic research are used to trace the transformations of Kharkiv’s urban form. Key results include the identification of two primary spatial models: the fortified city of the mid-17th century and the Sloboda-type settlements that emerged in the late 17th and early 18th centuries. The fortress acted as a defensive-administrative nucleus, while Slobodas developed into semi-autonomous residential units with social, functional, and professional differentiation. Over time, the regular planning grid of the growing imperial city overlapped with the organic morphology of the Sloboda settlements, forming a complex, layered spatial structure. Particular attention is given to how landscape factors and social organization influenced settlement location, spatial hierarchy, and the internal logic of neighborhood planning. The conclusion emphasizes that Kharkiv's development was not a linear progression from primitive to modern, but rather a process of accumulation and adaptation. The resulting urban morphology, shaped by multiple layers of socio-functional and territorial evolution, forms a valuable heritage and resource for future planning. The findings of the study can inform contemporary urban renewal policies by offering models for the integration of historic low-rise residential zones into the evolving structure of large cities, balancing spatial identity with the demands of modernization.
GREEN STANDARDS IN UKRAINE: CURRENT STATE OF THE PROBLEM
This article provides a comprehensive analysis of the current state of green standards implementation within Ukraine's construction industry. The study's relevance is underscored by global challenges, including climate change, natural resource depletion, and urbanization, which necessitate a transformative shift in the construction sector to achieve the Sustainable Development Goals (SDGs). Global practice consistently demonstrates the effectiveness of international certification systems such as LEED, BREEAM, and DGNB in reducing emissions, optimizing energy consumption, improving environmental quality, and fostering sustainable urban environments. However, despite isolated positive examples, the widespread adoption of these standards in Ukraine remains limited. This is primarily due to the absence of a comprehensive national "green" standard, one that is fully adapted to local conditions and effectively integrated into the state regulatory framework. While Ukraine's existing regulatory and legal framework contains fragmented provisions concerning energy efficiency and ecological design, it currently lacks a cohesive, systemic approach to green architectural practices. Particular attention is drawn to the imperative of adapting international best practices to Ukraine's specific socio-economic conditions and regional characteristics. The research employed a comprehensive methodological approach. This encompassed a systematic analysis of Ukraine's regulatory framework pertaining to ecological construction, a comparative analysis of leading international green standards (LEED, BREEAM, DGNB) and their correlation with the United Nations Sustainable Development Goals, and an empirical analysis of the market for ecologically certified buildings in Ukraine as of April 2025. The findings indicate that Ukraine has established a foundational regulatory framework that addresses certain aspects of ecological building certification, particularly in areas like thermal insulation, energy efficiency, and resource metering. A review of relevant laws, state building norms (DBNs), and ministerial orders confirms the government's aspiration to integrate sustainable development principles. Furthermore, international green standards (LEED, BREEAM, DGNB) demonstrate a high degree of alignment with the SDGs, encompassing their environmental, social, and economic dimensions. The analysis of the market for certified properties revealed a limited number of completed projects (only a few dozen), predominantly concentrated within the public and office building segments in major cities, while the residential sector remains largely untouched by "green" certification. The study confirms the existence of significant challenges, yet simultaneously highlights substantial potential for the advancement of green building in Ukraine. There is a clear need for the development of a holistic national green standard specifically tailored to Ukrainian peculiarities. Additionally, the establishment of a unified national register for certified buildings is crucial for data systematization and promoting ecological standards among developers and the general public. The systemic implementation of green standards in Ukraine must be grounded in a robust legislative framework, the integration of international experience, adherence to SDGs, and scientifically substantiated adaptation to the national context. Future research will focus on developing a template for a national green standard that accounts for regional specificities and incorporates the visual and aesthetic qualities of architecture into its criteria.
IMPROVEMENT OF COLD CONCRETE JOINTS USING WET GRINDING METHOD
The article considers the process of cold joints formation that arise as a result of interruptions during the placement of concrete mix and can significantly affect the subsequent mechanical behavior of concrete and reinforced concrete structures. The characteristic defects that are formed both at the manufacturing stage and during the operation of structural elements, as well as their impact on durability and load-bearing capacity, are analyzed in detail. Special attention is paid to modern methods and materials used for the repair and restoration of damaged concrete elements, in particular, special repair mixtures, modified cements, chemical additives and approaches to base preparation. One of the key methods considered in the work is the technology of wet shotcrete, which allows for effective restoration of damaged areas and ensuring high-quality adhesion between old and new concrete. The features of regulating the technical properties of repair mixtures by using optimal compositions, selection of aggregates, modification of the mixture and control of hardening conditions are presented. The importance of proper surface preparation of existing concrete is emphasized, which largely determines the quality of the contact zone. The study is aimed at determining the optimal parameters for applying repair materials by shotcrete. In laboratory conditions, partial application of a 1 cm thick layer of repair mixture was used using a compact test rig. A method for determining the tensile strength of fine-grained concrete during bending was developed using standardized forms modernized with special partitions. Prepared halves of beams with surface angles of 90°, 45° and 22.5° to the horizontal were used as elements of "old concrete". Such a design solution allowed to increase the contact area, minimize flow turbulence during spraying and assess the influence of the spatial position of the cold joint. Within the framework of the study, a two-factor nine-point experimental design was formed, in which the angle of the cold joint plane (90°, 45°, 22.5°) and the speed of spraying the shotcrete-fiber concrete mixture (0 m/s, 35 m/s, 70 m/s) were varied. A set of experimental tests was carried out, the results of which are presented and analyzed in the work, which allowed us to establish the regularities of changes in the strength and nature of the fracture of the repaired samples.
ARCHITECTURE OF AN AUTONOMOUS INTELLIGENT SYSTEM FOR MANAGING CONSTRUCTION PROCESSES UNDER THE RISK OF EXTERNAL IMPACTS
This paper explores the problem of ensuring the autonomy and fault tolerance of intelligent control systems used in construction process management under conditions of external risks, such as power outages, loss of network connectivity, or cyber-attacks. As artificial intelligence (AI) becomes increasingly involved in construction scheduling, monitoring, and resource coordination, there is a pressing need to develop system architecture capable of maintaining critical functionality under infrastructure failures. The main objective of this research is to design and formalize a model of an autonomous AI-driven system that can operate independently from centralized infrastructure and seamlessly transition to fallback control logic when needed. The methodology combines system architecture analysis, the use of UML diagrams (use case, component, and state diagrams) to model functional logic and interactions, risk scenario modeling using failure analysis techniques, and a comparative evaluation of centralized and edge-based computing approaches. The proposed three-layer architecture (physical, computational, and communication) is centered on a local edge server. This server hosts AI modules, handles anomaly detection, power switching, and provides decision-making capacity independently of cloud services. The results demonstrate that the implementation of a hybrid autonomous control system significantly enhances the resilience of construction operations. The edge-based architecture outperforms centralized models in response time, offline operability, and stability in unstable environment. A comparative analysis shows that the deployment of such a system may increase initial costs by 5–10%, yet these costs are justified by a substantial reduction in risk of downtime, delays, and data loss. The proposed system is particularly suitable for construction sites operating in constrained or high-risk conditions, including strategic infrastructure projects or military-affected zones. Future research should focus on optimizing AI algorithms for offline operation, developing industry-wide integration protocols, and validating the proposed model through real-life implementation in pilot projects.
IMPROVING TEMPERATURE DISTRIBUTION EFFICIENCY USING A SWIRLING AIR JET
Effective control of thermal processes in air flows is an important condition for improving the energy efficiency of ventilation and heat engineering systems. The aim of the study is to analyze the processes of reducing excess temperature in an isothermal free swirling air jet, followed by the improvement of approaches to regulating the thermal characteristics of the flow. The relevance of the work is determined by the need to enhance the energy efficiency of ventilation systems and heat engineering equipment through the optimization of temperature fields. The main task consisted in analyzing the processes of thermal decay, calculating the corresponding coefficient, and constructing temperature profiles in cross-sections of the jet. To simplify the mathematical description, a temperature attenuation coefficient was introduced, which makes it possible to more clearly assess the dynamics of heat dissipation. A quantitative study of axial temperature distribution was carried out, dependence graphs were constructed, and the nature of changes in different jet zones was determined. An efficient method for calculating relative temperature values in arbitrary cross-sections was proposed. To account for the influence of gravitational forces on the development of the thermal field, the dimensionless Archimedes number was applied. The temperature distributions in the jet were described on the basis of a generalized analytical model similar to the Schlichting model, adapted to thermal problems. The results of the study are presented in the form of generalized graphical dependencies and formulas with correction coefficients. A comparison of experimental observations with analytical modeling results demonstrated a high degree of agreement between the obtained data and theoretical predictions. The analysis also covers the formation of turbulent thermal structures during jet cooling. The possibility of regulating the temperature profile by changing boundary conditions and initial parameters is shown. The obtained conclusions can be effectively applied in the design of ventilation systems, heat engineering equipment, and energy units, where the uniformity of temperature distribution in the air environment is critical. The presented results provide a foundation for further research on nonlinear heat transfer effects under external disturbances and will contribute to the development of algorithms for automatic microclimate control in enclosed spaces.
THE EFFECT OF MECHANICAL ACTIVATION OF MIXED PORTLAND CEMENT IN THE PRESENCE OF A SUPERPLASTICIZER ON THE COMPRESSIVE STRENGTH OF CEMENT STONE
The presented article provides experimental results related to determining the influence of mechanic activation of mixed Portland cement and a superplasticizing admixture on the physical and mechanical properties of cement stone under compression at the ages of 3, 7, and 28 days. Such cement was obtained by mixing Portland cement PC-I 500 with ground quartz sand, the amount of which varied within the range of 30–60 % of the total binder mass. A promising method for increasing the compressive strength of cement stone is intensive mechanic and chemical activation of mixed cement in a high-speed turbulent-type activator in the presence of a superplasticizer SP-5, the content of which varied from 0 to 1 % of the binder mass. The research was carried out using D-optimal mathematical experimental design, with variation of the following factors: consumption of ground quartz sand (45 ± 15) % of the mixed binder mass and the amount of superplasticizing admixture (% of the mixed binder mass). The cement-water mixture was prepared using two technologies: the first with a high-speed activator (rotor speed 1500 rpm) and the second by traditional (control) mixing. The obtained mathematical models indicate a significant influence on the compressive strength of the cement stone by both the formulation factors (X₁, X₂) and the technological parameters of the mixing process. It should be noted that the combined effect of mechanic and chemical activation, the amount of ground sand, and the superplasticizer makes it possible to increase the compressive strength of the cement stone (compared to the control) by 22…41 %, which allows a substantial increase in the proportion of ground quartz sand in the mixed binder composition as a mineral additive to cement.
DROPLET METHOD FOR INVESTIGATING THE CAPILLARY–POROUS STRUCTURE OF MATERIALS
A simple express methodology is proposed for the non-destructive characterization of the capillary–porous structure of building materials, based on monitoring the spreading dynamics of a colored droplet applied to the surface of a specimen. The method relies on recording the temporal evolution of the stain and interpreting the resulting R²(t) dependence within the Lucas–Washburn framework and porous-media theory. This enables, in a single experiment, the evaluation of effective porosity, capillary conductance, permeability, mean effective pore radius, effective diffusion coefficient, as well as wetting parameters (contact angle, surface tension) and indicators of deviation from the ideal capillary regime. The experimental procedure consists of video recording the spreading of a droplet of aqueous dye solution (e.g., methylene-blue), followed by frame extraction and computer processing of the stain contours. From the stain area, an equivalent radius is obtained, the R²(t) relationship is constructed, and its slope is used to extract integral capillary characteristics of the material. The approach provides high informational value at minimal equipment cost, making it suitable for field applications and preliminary screening of restoration zones. Using shell limestone as an example, it is demonstrated that the method allows quantitative identification of structural variations even within a single block or layer-an essential requirement for selecting compatible primers and restoration mortars with controlled rheological and adhesive properties. A consistent data-processing workflow is outlined: linearization of the R²(t) dependence, determination of capillary conductance, evaluation of effective porosity from the absorbed liquid volume, and reconstruction of permeability and contact angle values based on known liquid parameters. Verification criteria for assessing the plausibility of the obtained values are presented, including penetration depth and typical ranges of permeability and mean pore radii for cemented carbonate rocks. The proposed methodology effectively complements diagnostic approaches already used in restoration practice and provides a parametric basis for selecting mixtures adapted to the real geometry of the substrate’s capillary–porous network. Thus, the developed droplet-based analysis toolkit combines operational simplicity with the ability to obtain key structural characteristics required for scientifically grounded design of repair and restoration solutions for shell limestone e heritage objects.
RESEARCH ON THE INFLUENCE OF MINERAL OILS ON THE STRENGTH AND AVERAGE DENSITY OF HEAVY CONCRETE
The article investigates the effect of mineral oils on the strength and volumetric weight of heavy concrete. Heavy concrete is the main material in construction, used to create structures with increased requirements for strength and stability, however, the effect of chemical agents, such as mineral oils, on its properties remains insufficiently studied. The study of this aspect is important for improving the durability and safety of concrete structures, in particular those exposed to oils in industrial processes or accidents. The aim of the study was to study how different types of mineral oils (transformer oil T-1500, engine oil 10W-40, IGP-30, both new and used) affect the physical and mechanical characteristics of heavy concrete, in particular its strength and volumetric weight. The experiments were carried out on concrete samples measuring 100×100×100 mm, made of Portland cement, under standard storage conditions. Oils were applied by two methods: immersion of samples in oil and application with a brush. The results of the studies showed that the most significant effect on the strength and volumetric weight of concrete was the method of immersion of samples in new transformer oil T-1500, where after 30 days a significant increase in weight by 1.18% and compressive strength by 13.06% was observed. The use of waste oils and the method of applying oil with a brush led to a decrease in the strength of concrete, in particular, when using waste motor oil 10W-40, the strength decreased by 63.74% on day 30. At the same time, application of oil with a brush caused mainly superficial changes, without significant improvements or even a decrease in the strength of concrete. The results confirmed that the type of oil, its condition and the method of application have a significant effect on the mechanical properties of concrete. The study indicates the importance of choosing methods for protecting concrete structures from the negative effects of chemical agents and opens up prospects for further research in this area, in particular the development of technologies that reduce the impact of mineral oils on the durability and strength of concrete.
RESEARCH ON THE PROPERTIES OF SILICATE COMPOSITES FOR OPEN-ENVIRONMENT OBJECTS
The article presents a comprehensive study of the properties of silicate composites and materials based on them, aimed at substantiating the feasibility and effectiveness of their application in the field of landscape architecture for open-air objects. In particular, attention is focused on the possibilities of integrating such materials into the processes of spatial organization of parks and recreational areas, which is an urgent task of modern urban planning. The study considers key aspects that determine the operational potential of silicate composites, including their structural and technological characteristics, indicators of durability, environmental safety and aesthetic appeal. Special emphasis is placed on the analysis of the potential use of silicate composites in the creation of small architectural forms, decoration of open spaces, as well as in the formation of functional components of the urban environment. The presented advantages of these materials in the context of modern construction demonstrate their ability to provide not only architectural expressiveness and functionality of objects, but also to reduce financial costs for their construction, further operation and maintenance. The article emphasizes the importance of using environmentally friendly raw materials in the production of silicate composites, which contributes to reducing the negative impact on the environment and complies with the principles of sustainable development in architectural practice. The study includes calculations and analysis of experimental and statistical models that demonstrate the relationship between the structural parameters of materials and their operational characteristics. In particular, detailed studies of such physical and technical indicators as compressive strength, frost resistance, water resistance, density, crack resistance and carbonization resistance were carried out. A comprehensive analysis of these criteria allowed us to draw reasonable conclusions regarding the prospects for the use of silicate composites in the design of architectural elements of the environment, landscape design for open-air facilities and the rational organization of outdoor spaces in modern urban conditions.
ANALYSIS OF STRUCTURAL FAILURE MECHANISMS IN BUILDINGS SUBJECTED TO BLAST LOADS
This paper presents a comprehensive analysis of damage to buildings and infrastructure resulting from military actions, with a particular emphasis on modern conflicts and their devastating consequences. The primary focus is on a profound examination of various factors causing deformation and destruction: from the destructive effects of explosive shock waves and dynamic loads to mechanical impacts (shrapnel, direct hits) and intense thermal factors (fires, high-temperature exposures).The study encompasses a representative sample of over 150 structures of various types, located in active combat zones. This enabled a detailed examination of typical failure and degradation mechanisms in key structural systems, such as panel buildings, traditional brick masonry, monolithic and precast reinforced concrete structures, as well as lightweight frame and rapidly assembled constructions. Key findings confirm the empirically established pattern that the intensity of damage decreases exponentially with increased distance from the explosion's epicenter, which is crucial for hazard zoning. A significant correlation was also established between the nature of the consequences, the type of explosion (airburst, ground-level, subsurface), its power, and the structural features that determine a building's inherent resilience to external influences. To accurately assess the parameters of explosive waves, including their pressure, impulse, and duration, advanced methods were employed. These methods combine empirical formulas derived from field tests with high-precision numerical modeling using the finite element method (FEM). Based on the comprehensive analysis, a set of practical recommendations is proposed. They include the use of more durable, ductile, and energy-absorbing materials, the retrofitting and strengthening of existing buildings, and the optimization of urban planning solutions, considering principles of protective design and infrastructure dispersion. The objective of this work is not only to document and analyze damages but also to significantly improve existing methodologies for calculating structural responses to blast loads. Furthermore, the study investigated the impact of secondary factors such as collapses, ground deformations, and subsequent settlements, which often accompany primary destructions and exacerbate the overall condition of affected objects.
PRACTICAL METHOD FOR CALCULATION OF MONOLITHIC FLOOR SLABS STRENGTHENING WITH STEEL BEAMS
The method of strengthening of monolithic reinforced concrete slabs with steel beams in the lower zone is considered. From the late 1990s to the present, residential and civil construction in our country has been based on monolithic frame technology, where flat slabs are mainly used. Slabs often need to be strengthening as a result of damage caused by various reasons or when architectural and planning solutions are changed. Strengthening of such slabs with steel beams is used quite often in construction practice, especially in cases where it is not possible to fully unload the slab structure. The technical solutions for this method of strengthening have been developed for a long time and have many variations. However, if we analyse the building codes in the field of reconstruction and strengthening, we can identify a certain lack of calculation methods for the analysis of strengthening structures. A slab in a monolithic frame system is a repeatedly statically indeterminate structure, so its adequate calculation without the use of modern software systems is hardly possible. A review of the current building codes in the field of reconstruction and strengthening is carried out. A number of publications in professional journals devoted to this topic and calculation approaches in the design of strengthening are considered. The structural features of strengthening with unloading beams are analysed. A practical methodology for calculating monolithic slabs strengthening with beams in the lower zone using the LIRA-SAPR software package is proposed. The methodology is based on taking into account the initial deformed state of the floor slab. The calculation is carried out by a step-iterative method, taking into account the physical-nonlinear properties of reinforced concrete and the life cycle of the structure. Particular attention is paid to the method of modelling the contact zone "slab-strengthening beam". The contact zone is modelled by means of one-sided connection, which perceives only compression forces. The presented calculation algorithm has been tested by the author in the design of many facilities that have been implemented and successfully operated for a long time.
NUMERICAL MODELING OF THE IMPACT OF COMPLEX LOADS ON BUILDING MATERIALS
The article is devoted to the urgent problem of predicting the durability of building materials and structures exposed to complex multifactorial loads, including mechanical, thermal, seismic, and corrosive effects. Current trends in construction, especially in areas with high risks of military damage and natural disasters, require scientifically grounded methodologies for assessing the performance of materials under real operating conditions. The study presents a comprehensive analysis of numerical modeling methods, with a particular focus on the finite element method (FEM). This approach enables detailed reproduction of the stress–strain state and makes it possible to account for nonlinear interactions between different types of loads, which is essential for accurate predictions of material service life. Special attention is paid to algorithms that integrate mechanical, seismic, and thermal effects into a unified model, as well as the application of combined methods, including the boundary element method, the Monte Carlo method, and finite differences. The proposed numerical schemes were validated against experimental data, confirming high accuracy with deviations not exceeding a few percent. An additional innovative aspect of the research lies in the integration of classical numerical methods with machine learning technologies, particularly deep neural networks, which allow the consideration of complex nonlinear degradation patterns of materials over time. The study also emphasizes the integration of numerical models with monitoring systems based on IoT sensors. Such an approach ensures real-time dynamic control of the technical state of building structures and enables the timely identification of critical deviations. It has been demonstrated that the application of these algorithms not only improves the accuracy of residual life predictions but also significantly reduces costs by implementing resource-saving restoration technologies. The conclusions outline future research directions, including the extension of numerical modeling methodologies for novel high-performance materials, the advancement of machine learning techniques, and the creation of fully automated systems for monitoring and predicting the technical state of building structures.
URBAN PLANNING PRINCIPLES AND GENERAL APPROACHES TO THE CONCEPT OF RESTORING URBAN AREAS AND CITIES THAT WERE SUBJECT TO DESTRUCTION
The purpose of the work is to develop basic urban planning principles and conceptual foundations for the reconstruction of highly urbanized territories that have been destroyed for the tasks of restoring the urban settlement system. An analysis of the experience of restoring cities and territories in the post-war period was conducted. Positive examples are based on an integrated approach with compliance with two conditions ‒ the involvement of local communities and the development of comprehensive development strategies. situational response ‒ when solving the tasks of urban development, provided many negative consequences of a significant scale. At the initial stage of anti-crisis management, the priority task is to update the city's general plan. The general plan acts as a key document that formalizes the rules, priorities and tasks of urban development activities. The restoration of territories in conditions of reduced urban potential has a number of specific features: a decrease in population, loss of industrial production, as well as the degradation of transport and engineering infrastructure. This is accompanied by a general deterioration in the qualitative and quantitative indicators of the development of the urban environment. During the development of the updated general plan, modern principles of spatial development should be laid down: safety, environmental friendliness, autonomy, energy efficiency, convenience and comfort, transport accessibility, creation of conditions for employment. It is proposed to structure the restoration process by hierarchical levels and types of objects. It is also worth identifying the subjects of management related to reconstruction and forming an information package for planning and implementing design solutions. The matrix for analyzing planning units of destroyed territories is proposed as a tool that allows for typology, determining priorities and creating a basis for forming regulatory regulation of restoration. It is proposed to use a subject-oriented restoration model.
RE-CREATION OF ARCHITECTURAL HERITAGE AS A SOURCE OF AUTHENTICITY
The problem of re-creation of architectural heritage has traditionally remained within the field of conflicting assessments. The classical doctrine established by the Venice Charter interpreted authenticity through the material substance of the monument; therefore, any re-creation was regarded as falsification. At the same time, historical experience shows that when not only the material fabric but also the very space of memory is lost, re-creation becomes the only means of restoring cultural continuity. At the turn of the 20th and 21st centuries, under the influence of the Nara Document, the Burra Charter, and the Riga Charter, the concept of authenticity expanded beyond material substance to include cultural, social, and semantic dimensions and, with this shift, the very understanding of re-creation also changed. The purpose of the study is to substantiate re-creation as a cultural act capable of generating its own authenticity. The methodological framework combines instruments of architectural and conservation practice with interdisciplinary approaches. The use of historical-analytical, comparative, system-structural, and hermeneutic methods made it possible to consider re-creation not merely as a technical procedure but as a cultural act in which architecture becomes a carrier of memory and a medium of reflecting on the past. As a result, a conceptual model of the multiplicity of authenticity was proposed (including material, functional, contextual, and conceptual dimensions), along with a typology of re-creation forms: scientific, representational, adaptive, imitative, and falsification. The article examines two polar forms – scientific and falsification – as examples of opposing strategies of interaction between authenticity and contemporaneity. The study demonstrates that re-creation is not the antithesis of authenticity: it may serve as its source, creating conditions for renewed experience and interpretation of the past. In this process, the genuine and the imagined, memory and the re-created image continuously interact, forming a new, dynamic authenticity. An open question remains whether a falsified re-creation can, over time, become living heritage – accepted by society as its own.
BIONICS AS THE FOUNDATION OF SUSTAINABLE DEVELOPMENT IN CONTEMPORARY ARCHITECTURE: ENERGY EFFICIENCY AND SYNERGY WITH THE ENVIRONMENT
The article explores bionics as a scientific and methodological foundation for creating sustainable architecture capable of energy-efficient functioning and achieving synergy with the natural environment. It examines the evolution of bionics from the formal imitation of organic forms to the comprehensive application of biomimetic principles. Through specific examples – such as the passive ventilation system of the Eastgate Centre in Zimbabwe, inspired by termite mound architecture, and façade concepts that mimic photosynthesis – the article reveals mechanisms for implementing bionic design solutions. Particular attention is given to analyzing the energy efficiency, adaptability, and resource-saving characteristics of bio-inspired architectural objects. The study highlights the contemporary understanding of bionics, which focuses on the principles of cyclicality, adaptability, and zero-waste design derived from natural ecosystems. It provides a detailed analysis of examples ranging from passive ventilation and thermal regulation systems modeled after termite mounds to adaptive façade systems that imitate photosynthesis and plant regulatory mechanisms. Special attention is paid to environmental synergy achieved through efficient resource management – for instance, mimicking water-harvesting strategies of desert insects or adopting lightweight yet durable structural analogues inspired by biological prototypes such as bone or spider silk to minimize material consumption. The discussion systematizes the advantages of the bionic approach – including enhanced energy efficiency, reduced operational costs, and improved comfort – while also addressing the challenges of its implementation, such as high research costs and the need for interdisciplinary collaboration. The article substantiates the idea that bionics serves not only as a tool for solving engineering problems but also as a catalyst for shaping a new architectural philosophy aimed at fostering harmony between the built and natural environments. The practical significance of the study lies in its potential use by researchers, educators, graduate students, and practitioners engaged in related scientific and design inquiries.
ANALYSIS OF THE ASSEMBLY DURATION OF A PRECAST-MONOLITHIC FRAME FOR A LOW-RISE BUILDING
The article is devoted to the analysis of precast-monolithic construction in Ukraine, which combines the advantages of both precast and cast-in-place frame systems while minimizing their drawbacks. For this reason, precast-monolithic solutions ensure the reliability and cost-efficiency required for contemporary and especially post-war reconstruction. The limited practical experience in constructing precast-monolithic buildings highlights the need for real-world testing of structural and organizational-technological solutions. The aim of the study is to perform multivariate organizational-technological modelling and compare its results with the actual construction process of an experimental low-rise precast-monolithic building. The research methodology includes analysis of scientific sources, construction organizational-technological modelling, examination of labour- and machine-hour regulatory standards, as well as on-site observation and time-tracking of construction processes during the erection of the experimental building. The study produced the following results. It is recommended that organizational-technological modelling of precast-monolithic structures be based on current 2023 regulatory standards, with the option of applying multivariate modelling using regulatory frameworks from the past 40 years when necessary. The experimental construction of a cottage with dimensions 14×10.5 m (socket-type foundations, 0.3×0.3 m columns, hollow-core slab floors) revealed production challenges during frame erection and enabled a comparison between actual and regulatory values of construction duration and labour intensity. The duration of erecting this precast-monolithic frame amounted to 9, 12, and 24 working days under optimistic, realistic, and pessimistic scenarios, respectively. Adjustment coefficients to normative values were calculated to support scenario-based planning for the erection of precast-monolithic frames. To account for possible force-majeure conditions, time buffers of 1–4 weeks should be provided. The results of the study may be useful for multivariate organizational-technological modelling of precast-monolithic buildings of various types and purposes.
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DRY CONSTRUCTION MIXTURES BASED ON PHOSPHOGYPSUM MODIFIED FOR MOTOR ROADS
The relevance of the disposal of phosphogypsum ‒ an output of the chemical industry ‒ through the route of their processing in dry wastewater is shown. The disposal of technogenic waste creates a unique opportunity for such important aspects as a significant reduction in financial investments in the industrial activity of enterprises. Implementation of the primary activities of enterprises is of great importance. On the basis of existing enterprises, subsidiaries with individual tasks are being developed, which are evolving from the previous ones, which means they are seeing the development of new, promising, "lighter" ones technology. The use of man-made waste will provide not only financial savings, but also reduces costs for housekeeping and housekeeping. An important positive aspect is the change in environmental impact on the atmosphere and water basin of the planet. Therefore, the massive recycling of industrial waste is a key problem at the current stage of activity of industrial companies. The variety of products made from technogenic phosphogypsum is economically viable. The effectiveness of utilization of phosphogypsum as a high-acidity man-made product that is created in the process of production of superphosphate minerals has been shown. During the process of heat treatment and modification, dihydrous phosphogypsum is processed in a modified mixture; the sequence of technological processes is broken down. A description of the processes has been carried out and a low-energy technological process has been selected, which will ensure faster energy consumption and resource savings. The stagnation of dry waste products has also been implemented. It is shown that of dry building mixtures is a scientific product of high-tech factory processes, which allows increasing the intensity and speed of road work while reducing the economical warehouse process. The results of experimental research on the curing of modified phosphogypsum in milk berry for the preparation of dry wake-up bags for the basics of road clothing are presented.
INVESTIGATION OF STRUCTURE FORMATION PROCESSES IN LIME-BASED RESTORATION COMPOSITES
The operational properties of composite materials are largely determined by the processes that occur at the beginning of their structure formation. Volumetric changes and plastic strength are considered as informative indicators reflecting the processes of structure formation and adaptation of lime restoration composites (plaster compositions) in the early stages of hardening. It is shown that these characteristics are sensitive to changes in the internal structure of the material, in particular to the coagulation of dispersed particles, the development of interphase contacts, and the formation of a spatially connected composite structure. The results demonstrate that volumetric changes and plastic strength reflect different but interrelated aspects of a single process–the formation of the internal structure of the composite and therefore can be considered as complementary indicators of structural evolution. The correlation between these indicators determines the ability of the restoration mortar to adapt to the deformation and moisture exchange characteristics of the porous limestone base without accumulating critical internal stresses. Based on experimental data, regression models and graphical dependencies were constructed, which clearly reflect the influence of composition on the nature of volumetric deformations and the kinetics of plastic strength growth. The obtained isosurfaces and time curves allow interpreting the change in properties through the dominance of certain mechanisms of structure formation at different stages of hardening. It has been shown that varying the composition of the composite allows for targeted control of the balance between deformability and the rate of increase in structural cohesion, which is a key factor in the formation of a compatible and stable contact zone.<span lang="UK" style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; letter-spacing: -.15pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> The results obtained confirm the possibility of using volumetric changes and plastic strength as a methodological basis for predicting the behavior of restoration mortars and adaptation processes in the "restoration mortar – base material" system and for designing plaster compositions focused on long-term compatibility and preservation of historic shell limestone buildings.
REGULATORY AND LEGAL CONCEPTUALIZATION OF ENERGY EFFICIENCY OF BUILDINGS
The article is devoted to a comprehensive study of the regulatory and legal conceptualization of energy efficiency of buildings in Ukraine in the context of the implementation of European standards and the formation of a national legal regulation system. The evolution of the conceptual apparatus from the term "energy saving" to "energy efficiency" is analyzed, which reflects the transition from quantitative restrictions on consumption to improving the quality of energy use in accordance with the requirements of Directive 2010/31/EU on the energy performance of buildings and Directive 2012/27/EU on energy efficiency. The basic legislative acts are studied, in particular the Law of Ukraine "On Energy Performance of Buildings", the Law of Ukraine "On Energy Efficiency" and the creation of the Energy Efficiency Fund as an institutional mechanism for supporting the thermal modernization of residential buildings with total funding of over 2 billion UAH. The main legal regulatory instruments are identified: a system of mandatory energy certification of buildings, energy audit, minimum requirements for energy efficiency of new buildings and the concept of buildings with a near-zero energy consumption level. An analysis of by-laws and technical standards that form a comprehensive regulatory system from design to operation of buildings, including methods for calculating energy characteristics and energy efficiency classification, was carried out. It was established that Ukrainian legislation successfully integrates European approaches, creating a legal basis for a systematic reduction in energy consumption in buildings and achieving climate goals by 2050. The practical implementation of the concept demonstrates positive results in the period 2018-2023. The average level of energy savings after thermal modernization is 31.3%, which confirms the effectiveness of legal mechanisms for stimulating energy efficiency and the need for further improvement of the regulatory framework.