Academic journal Industrial Machine Building Civil Engineering
Presenting the researches results in the area of building works mechanization, design and exploitation of building structures and their improvement, examining the current problems of soil mechanics, geotechnics and foundation engineering.
National University «Yuri Kondratyuk Poltava Polytechnic»
Assessing the reliability of noise simulation models in a built-up area
In modern environments, noise is a dominant factor negatively impacting the urban ecosystem and, consequently, the health of city residents. Noise exposure reduces labor productivity and the efficiency of rest, serves as a primary cause of nervous disorders, and significantly diminishes the quality and safety of life. The aim of the study is to determine the reliability of developing simulation models for sound propagation in urban built-up areas. Research methods include field instrumental measurements, a cartographic method for predicting noise pollution from sources with the construction of 3D sound field models, and statistical methods for processing and evaluating research results. The results demonstrate a strong relationship between the outcomes of field instrumental measurements and the cartographic prediction of the noise regime in the studied residential area. The calculated correlation coefficient amounted to r = 0.889, indicating a high level of agreement between the compared datasets. In addition, the required number of observations to determine the degree of correlation between the two groups of compared sound level values was established as 12 observations
Copyright (c) 2025 Petro Sankov, Yuriy Zakharov, Vadim Zakharov, Nataliia Тkach https://creativecommons.org/licenses/by-nc-sa/4.0
Experimental and numerical study of full-scale reinforced concrete beams with 3DCP permanent formwork
The performance of a box-type permanent 3DCP formwork for full-scale reinforced concrete beams was assessed through experimental testing and numerical analysis. Eight beams were tested under four-point bending to examine the contribution of the printed shell to stiffness, crack development, and load-bearing capacity. The specimens exhibited a flexural–shear failure mechanism, while no delamination between the printed shell and the cast-in-place core was observed. A nonlinear finite element model was calibrated against the experimental load–deflection responses and then used for comparative simulations. The predicted ultimate load was 81.9 kN for beams with 3DCP formwork and 77.1 kN for a numerically simulated reference beam without formwork. An energy-based assessment showed that the total strain energy decreased to 49.64 % at the same load level, indicating increased stiffness and improved efficiency of the composite cross-section.
Copyright (c) 2025 Petro Reznik, Anton Volodymyrov, Dzhamaldii Alataiev, Vladyslav Maksymenko https://creativecommons.org/licenses/by-nc-sa/4.0
Assessment of the morphological composition of secondary construction waste from destruction
The issues of post-war reconstruction of territories and settlements that suffered extensive damage as a result of hostilities are considered. Rational design and construction solutions are proposed that allow maximum use of the foundations of destroyed buildings for further reconstruction. It is determined that the planning solutions for the quarter development of industrial cities are imperfect and require updating in accordance with modern principles. A solution that significantly reduces the amount of work involved in dismantling the underground structures of buildings is to use them for the construction of new reconstruction objects. A combined solution is proposed for the joint use of the foundation array of a destroyed building and a monolithic grillage on bored piles. The use of diamond drilling technologies allows for the effective installation of piles in complex, swampy areas. It is proposed to construct the structure in the form of a system of soil foundation, artificial foundation, connected by a system of piles and foundation frames.
Copyright (c) 2025 Dmytro Shvydkyi, Vitaliy Shvets, Kostiantyn Sokolenko, Valeriy Sokolenko https://creativecommons.org/licenses/by-nc-sa/4.0
Reliability of Buildings and Structures: General Requirements, Terms, and Indicators
Modern buildings and structures, with their increasing complexity in design and operation, are transforming into unique engineering systems, the failure of which can lead to significant material, moral, and human losses. Ensuring their reliability is one of the most critical problems in the modern construction industry. This article systematizes the key provisions of reliability theory as applied to construction objects. The main terms, such as dependability (failure-free operation), durability, maintainability, and storability, are considered, and quantitative reliability indicators are analyzed. The evolution of calculation methods is investigated, charting the transition from outdated deterministic approaches (the allowable stress method) to modern probabilistic methodologies, which are based on the concept of limit states. The dynamics of reliability over the object's life cycle are discussed, highlighting the typical "bathtub curve" phases of burn-in, normal operation, and wear-out. The article identifies the key challenges in the practical application of modern probabilistic methods, particularly the gap between advanced theoretical models and the lack of systematized empirical data on failures, which is necessary for the accurate calibration of national standards.
Copyright (c) 2025 Mykhailo Klimov, Oleksandr Valovoi, Maksym Valovoi https://creativecommons.org/licenses/by-nc-sa/4.0
Invariance of reinforcement and concrete cohesion within the energy approach
The work studies the problem of analytical description of reinforcement and concrete cohesion, which determines the malleability of loop joints and butt joints of prefabricated reinforced concrete structures. It also proves that existing empirical and semi-empirical models like ‘tangential stresses – displacement’ do not ensure accurate impact of common stress in reinforcement and are unable to describe the plastic stage of tenacity characterised by a transition to a quasi-uniform distribution of tangent stress along the anchoring length. The study suggests a universal analytical bond model built on a two-line chart ‘with a linear initial section where tangential stress depends on common stress in the reinforcement and a horizontal section that corresponds to the plastic stage. The level and the length of the plastic stage are determined due to the conditions for preserving the energy invariant of the bond. The writers suggest the energy criterion for the beginning of the saturation stage, understood as the equivalence state of intensity of elasto-plastic components’ energy invariants. The resulting model allows the formation of physically justified bonding diagrams suitable for use in numerical methods for calculating the compliance of joints and butt joints. .
Copyright (c) 2025 Oleksandr Hryshchenko, Dmitro Kochkarev https://creativecommons.org/licenses/by-nc-sa/4.0
Stress-Strain State Analysis of a Shallow Spherical Shell Fabricated Using 3DCP
Experimental and numerical investigations of the stress–strain behavior and load-bearing capacity of a shallow spherical concrete shell fabricated using extrusion-based 3D printing are presented. The shell with a plan dimension of 2.2 × 2.2 m was subjected to quasi-uniform stepwise loading using sandbags. The maximum applied distributed load reached 13.74 kN/m², and the measured vertical deflections did not exceed 0.235 mm, indicating high structural stiffness. A three-dimensional nonlinear finite element model was developed in LS-DYNA to simulate the experimental behavior and to predict the ultimate load-bearing capacity, since it was not reached experimentally. It was found that failure of the 3D-printed shell occurs under a uniformly distributed load of 228.4 kN/m², which corresponds to a total load of 67.8 t. The numerical results showed good agreement with the experimental data, with discrepancies within 17%. The proposed experimental–numerical approach confirms the structural efficiency and feasibility of 3D-printed concrete shells for load-bearing applications.
Copyright (c) 2025 Olena Petrova, Dmytro Petrenko, Vladyslav Tenesesku, Oleksii Buldakov https://creativecommons.org/licenses/by-nc-sa/4.0
Modelling of Organo-Mineral Complexes in the System “Lime-Zeolite-Enzyme” for Purifying Technically Polluted Water from Suspended Solids and Compacting Sediment
The article presents the results of experimental and statistical modelling to determine the optimal composition of organo-mineral complexes for cleaning technically polluted water from suspended solids and compacting sediment in storage ponds at solid waste landfills during their reclamation and reconstruction. Water transparency with a turbidity index of 1.55 NTU they ensured by using an organo-mineral complex containing 7.25-8.25% quicklime, 2.5-3% zeolite and 7.5-8.25% enzyme. Sedimentation in the form of a sediment with a tensile strength of up to 160 kPa on the 28th day of exposure they ensured by using an organo-mineral complex containing 30.63-35% quicklime, 0-3.5% zeolite and 0-1.25% enzyme.
Copyright (c) 2025 Sergii Guzii, Andriy Tovmachenko, Volodymyr Viter https://creativecommons.org/licenses/by-nc-sa/4.0
Mobile 3D Mapping Using Geodetic Drones and GPS Navigation
The paper examines current trends in the development of geodetic mapping, with a particular focus on comparing traditional methods with innovative approaches. It is noted that classical techniques, such as the use of theodolites, levels, and GPS receivers – are still widely employed in engineering geodesy, although they present several limitations, including high labor intensity, the need for qualified personnel, and significant time consumption. At the same time, there is growing interest in automated solutions, particularly the use of unmanned aerial vehicles (UAVs), which enable rapid and accurate spatial data acquisition with minimal resource expenditure. The article emphasizes the importance of evaluating the effectiveness of different mapping methods in terms of accuracy, execution speed, and cost-efficiency, which is especially relevant in the context of the rapid development of the engineering and construction sectors.
Copyright (c) 2025 Денис Берун, Максим Філіпець, Аліна Чубакова, Віктор Вірченко https://creativecommons.org/licenses/by-nc-sa/4.0
Numerical studies of the resistance of concrete keyed joints with rectangular keys in reinforced concrete structures
Numerical investigations were carried out on the behavior of keyed joints with rectangular keys in reinforced concrete elements under different failure mechanisms. A two-dimensional nonlinear model was developed in Simulia Abaqus with the concrete damage plasticity approach, accounting for material nonlinearity and contact interaction between joint components. Various failure modes were received, including through-crack formation, key tearing-off, shear failure, and bearing surface crushing. It was investigated how the tensile and compressive strength parameters of concrete affect the bearing capacity of a concrete joint under different types of failure. The specifics of modeling such problems in Simulia Abaqus and the problems of solution convergence were studied.
Copyright (c) 2025 Oksana Demchenko , Mykola Myshchenko https://creativecommons.org/licenses/by-nc-sa/4.0
Research on the drive of a plant for the preparation and transportation of building mortars
Modern mixing plants for the preparation of mortar and concrete mixtures are an important component of construction technologies, which leads to increased requirements for their energy efficiency, operational reliability and stability of operation under conditions of variable loads. At the stage of designing the drive of the mixing plant, a well-founded determination of the power of the electric motor, gear ratios and kinematic parameters of the drive system requires special attention. The article examines the theoretical study of the drive of a compact installation for the preparation and pipeline transportation of construction mortars, the key design feature of which is the use of a single electric motor for driving a forced-action blade mixer and a piston solution pump through a common gear reducer and chain transmission. The kinematic scheme of the drive was analyzed taking into account the moments of inertia of the main elements of the system, dynamic models for estimating torsional oscillations were presented. The nature of variable moments of resistance caused by cyclic load from working bodies is considered. It was established that the dynamic loads that occur during the engagement of gears, starting and braking modes, as well as due to the unevenness of the resistance forces, significantly affect the fatigue strength and durability of the gearbox. The obtained results make it possible to substantiate the rational parameters of the drive, to propose measures to reduce peak loads and to increase the energy efficiency and reliability of small-sized installations for construction sites.
Copyright (c) 2025 Andrii Chyslo https://creativecommons.org/licenses/by-nc-sa/4.0
Changes in the Stress-Strain State of Precast Reinforced Concrete Floor Systems in Masonry Multi-Storey Buildings after Non-Design Impacts
The article is devoted to investigating non-design impacts on precast reinforced concrete floor systems of multistorey brick buildings that arise during military actions. The study examines the influence of both external and internal factors on these structural systems and their deterioration. Using the materials of the “Report on the Detailed Survey of the Residential Building in Chernihiv, damaged as a Result of Military Actions”, prepared by the State Research Institute of Building Structures (NDIBK) in 2022, the paper analyses the nature of the effects of military actions on the building as a whole and on its individual structural components, with particular attention to precast reinforced concrete floor systems. The case considered involves multiple direct artillery strikes on the building, which resulted in partial destruction of load-bearing structures and damage (or failure) of the associated floor elements. The findings of the analysis of this specific case provide a basis for further search, investigation, and development of new, more effective methods for restoring the serviceability of damaged precast reinforced concrete floor systems. This task remains highly relevant today and must consider not only the efficiency of restoration but also the safety of personnel working or residents living in buildings undergoing repair.
Copyright (c) 2025 Anton Hasenko, Andrii Kudlai https://creativecommons.org/licenses/by-nc-sa/4.0
Comprehensive analysis of stability and strength of thin-walled reinforced concrete elements based on energy approaches
This work develops and substantiates a comprehensive engineering method for the analysis of thin-walled reinforced concrete beams with a cross-sectional width of b = 40 mm, which unifies the verification of the stability of the plane form of bending and the evaluation of torsional deformability. The relevance of the research is driven by the need to refine the limit states for elements with a depth-to-width ratio of h/b ≈ 5.5, where classical methods fail to fully account for the interaction between flexural and torsional stiffness in the cracked stage. The methodological basis of the study is the energy invariance hypothesis, allowing the replacement of a real cracked reinforced concrete element with an equivalent elastic model accumulating similar potential strain energy. The paper combines a modified Prandtl-Vlasov algorithm for determining the critical buckling moment with an analytical model of torsional compliance accounting for discrete crack distribution. A key feature of the methodology is the detailed consideration of the dowel action of the longitudinal reinforcement, treated as a beam on an elastic foundation, which provides resistance to the mutual shear displacement of crack faces and significantly influences the effective torsional stiffness, GJeff. A comparative analysis established that increasing the width to 40 mm leads to an almost twofold increase in the out-of-plane moment of inertia, Iy, and the critical moment, Mcr. It is proven that such a change in geometry shifts the structural behavior from the risk zone of sudden (brittle) buckling, characteristic of narrower beams, to the zone of plastic failure along the normal section, where the stability safety factor exceeds unity. Furthermore, adjusted values of the reduction factor, kred, are proposed, accounting for the decreased sensitivity of the wider cross-section to initial geometric imperfections and concrete creep deformations
Copyright (c) 2025 Ivan Myroshnichenko https://creativecommons.org/licenses/by-nc-sa/4.0
Design of civil defense protective structures in residential multi-story buildings for individual use
The military actions in Ukraine, which daily create a threat to the civilian population, necessitate the development of new technical solutions for new construction and the reconstruction of existing buildings and structures. A large number of civilian casualties are residents of multi-story residential buildings. A typical protective shelter is considered to be a basement or cellar floor, the structural features of which are designed for utilities, pipelines, and technical equipment. They lack an emergency exit and proper ventilation, and do not provide for long-term stay with specific conditions in full compliance with the current regulatory requirements for the protection of the civilian population. As a result of the analysis of architectural and planning solutions, there is a need to improve premises where it is possible to integrate individual protective shelters, which are intended to provide proper protection in case of an emergency. The work examines the fundamental principles of approaches to designing individual protective shelters within the housing stock. The proposed recommendations can be used in designing new residential buildings, reconstructing existing buildings, and forming a system of individual protective shelters aimed at increasing the level of public safety in modern conditions.
Copyright (c) 2025 Dmytro Nikolaienko, Olena Filonenko https://creativecommons.org/licenses/by-nc-sa/4.0
Strengthening Technology for Damaged Floor Slabs through Compression Zone Enlargement and External Reinforcement
The article presents a technology for strengthening reinforced concrete floor slabs by enlarging the compressed zone and using external reinforcement. A 50 mm-thick monolithic overlay is installed on top of the slab, while steel channels are anchored below using chemical fasteners. The slab is pre-leveled with jacks; after hardening, the beams are removed. Full-scale hydrostatic tests confirmed the restored load-bearing capacity and minimal deflections (~2 mm). The method eliminates the need for dismantling, accelerates reconstruction, reduces costs by up to 58%, and preserves interior geometry - making it highly suitable for restoring war-damaged residential buildings.
Copyright (c) 2025 Oleg Kalmykov, Nina Psurtsieva, Kostiantyn Binkevych https://creativecommons.org/licenses/by-nc-sa/4.0
Experience in Strengthening Prefabricated Reinforced Concrete Floor Systems During the Rehabilitation of Industrial Buildings
The article presents practical experience in combined reinforcing of precast reinforced-concrete beams and hollow-core floor panels during rehabilitation of an industrial building at the Chornomorsk Oil and Fat Plant. The initial technical condition of the structures and the results of the instrumental inspection have been described. The existing structure, consisting of long-span beams (up to 12 m) and hollow-core slabs (9 m spans), had suffered physical deterioration, exhibited excessive deflections, and required increased load-bearing capacity for design loads of 10–12 kPa. A proposed constructive-technological system combines: an external cage-truss rigid steel longitudinal reinforcement, increasing the cross-section by reinforced cast-in-place concrete topping, and creation of a monolithic slabs-beams joints. The design of mounting plates and cage-truss to beams joints using chemical anchors is detailed, it includes CBFEM analyses using IDEA StatiCa that demonstrate sufficient capacity and acceptable transfer of forces to the concrete. The procedure for topping the slab is given, including placement of reinforcement cages into the hollow cores, mesh reinforcement across the slab, and staged concreting. Advantages of the combined approach for increasing stiffness and load-bearing capacity and measures to limit local effects on existing sections are analyzed. Implementation results confirm the effectiveness of the proposed solution for restoration and enhancement of operational performance of large-span reinforced-concrete structures in industrial buildings.
Copyright (c) 2025 Valentyn Marchenko, Dmytro Fedorov https://creativecommons.org/licenses/by-nc-sa/4.0
Rational design and construction solutions for the use of the foundations of demolished buildings for further reconstruction
Copyright (c) 2025 Dmytro Shvydkyi, Kostiantyn Sokolenko, Valeriy Sokolenko, Vitaliy Shvets https://creativecommons.org/licenses/by-nc-sa/4.0
Strength and force distribution of lap-welded composite longitudinal reinforcing bars formed during strengthening of reinforced concrete beam elements by increasing the cross-section in the tension zone
The article experimentally investigated the strength and stress-strain state of eccentrically stretched specimens from welded overlapped longitudinal reinforcing bars, which have cross-sections varying in length and are interconnected by electric arc welding. The strength of reinforcing bars of a composite cross-section was compared with the strength of individual centrally stretched reinforcing bars. As a result of the experiment, the influence of the main factors on the strength of the bars was investigated: electric arc welding; stress concentration; eccentricity of the application of longitudinal tensile force, as well as the distribution of forces in the sections of each element along the length of the composite reinforcing bar-sample
Copyright (c) 2025 Anna Azizova, Dmytro Ovsii, Oleksandr Semko, Mykola Ovsii https://creativecommons.org/licenses/by-nc-sa/4.0
Specific aspects of vertical roller mills design selection
The article analyzes specific design selection aspects of vertical roller mills, essential for grinding materials like granulated slag in the cement and mining industries. The research focuses on improving mill’s working elements to enhance efficiency, reduce energy consumption, and increase wear resistance under harsh operating conditions. Modern innovative designs, including multi-roller and modular concepts with active redundancy, are reviewed for improved reliability. The comminution principle relies on energy-efficient compression and shear within the material bed. A comparative analysis of various mills configurations, differing in roller and table geometry, is presented, demonstrating how design adaptations such as specialized rollers for high-moisture slag optimize performance, wear rate, and energy efficiency.
Copyright (c) 2025 Mykola Klymenko, Vasyl Marach https://creativecommons.org/licenses/by-nc-sa/4.0
Development of the statistical approach to the calculation of building structures
The current method of calculating building structures by limit states (previously by allowable stresses) is essentially semi-probabilistic. Meanwhile, in parallel with this dual method, for many years, fully probabilistic (statistical) approaches to the calculations have been developed. The aim of the article is to consistently review the approaches developed over the course of ninety years to the implementation of general probabilistic methods for calculating building structures, starting from the 1930s to the present. It is emphasized that domestic specialists are actively developing probabilistic methods, the results of which are implemented in regulatory documents. The prospects of the results of this scientific direction in creating a new generation of building design standards are noted.
Copyright (c) 2025 Sergii Pichugin https://creativecommons.org/licenses/by-nc-nd/4.0
Transforming Occupational Safety and Civil Defense: Wartime Challenges and Solutions
This article is dedicated to the urgent need for a fundamental reform of traditional occupational safety and civil defense systems under the conditions of a full-scale war. It examines new, previously unseen risks to the life and health of employees caused by military actions. These threats extend far beyond conventional occupational hazards, including direct missile strikes, the destruction of buildings, cyberattacks, and a severe impact on the mental health of personnel. It is proven that old approaches to occupational safety, which focused on preventing accidents in peacetime, are completely unable to cope with the dynamic, unpredictable, and aggressive nature of military threats. The paper substantiates the urgent need to integrate civil defense measures into the occupational safety management system, transforming two separate systems into a single, holistic, human-centric safety model at the level of each enterprise. Special attention is given to how digital technologies, particularly artificial intelligence (AI), can assist in this process. It demonstrates how AI can predict threats based on the analysis of large volumes of data, automate alert systems, optimize evacuation routes in real time, automatically assess damage, support decision-making in crisis situations, and provide psychological support to personnel. A conceptual model of such an integrated occupational safety and civil defense system, enhanced by AI tools, is proposed. This allows for a shift from a simple reaction to events towards proactive, preventive safety management. Finally, practical and scalable recommendations are formulated for enterprise managers to help them incrementally implement technological innovations into safety processes to increase the resilience and protection of personnel in wartime conditions, even with limited resources.
Copyright (c) 2025 Volodymyr Pogrebnyak, Oleksandr Kondrat, Iryna Perkun, Andrii Pogrebnyak https://creativecommons.org/licenses/by-nc-sa/4.0
Experimental studies of the strength of masonry under axial and local compression
Masonry is one of the traditional building materials that remains highly relevant in modern civil and industrial construction. Determining its strength characteristics, especially under compressive loads, remains an important scientific and technical task, since such forces prevail in load-bearing walls, columns, and other structural elements of masonry. The compressive strength of masonry is affected by numerous factors, including the strength and geometric properties of the units, their shape accuracy, the presence of voids, the mortar strength, the deformation characteristics of hardened mortar, the workability of the mortar mix, the bond strength between mortar and masonry units, the degree of joint filling, the bonding pattern, and the overall quality of workmanship. When determining the strength of masonry under local compression, the nature of the sample's destruction is taken into account, on the basis of which a corresponding kinematic scheme is developed that determines the main parameters that affect the strength of the masonry. One of the key issues is the lack of a unified approach to determining the geometric parameters of the samples used for testing. The objective of this study is: 1. to develop scientifically based recommendations for the optimal shape and size of standard samples that allow the most reliable assessment of the axial compressive strength of masonry based on test results; 2. to consider the case of local compression of walls by stamps located near the end face with a width less than the wall thickness.
Copyright (c) 2025 Maryna Pents, Oksana Dovzhenko https://creativecommons.org/licenses/by-nc-sa/4.0
Structural Features and Survey Results of the 18th-Century Illinska Church in Korop
The article presents the results of a comprehensive study of the 18th-century Illinska Church located in the urban-type settlement of Korop, Chernihiv region, which is a valuable monument of Ukrainian Baroque architecture. The aim of the study was to identify the structural characteristics of the building and to determine the technical condition of its main elements. The research utilized archival materials that made it possible to reconstruct the history of construction and subsequent renovations, as well as data from on-site surveys conducted by the author during field expeditions.The main attention was focused on the analysis of the masonry walls, the wooden floor structure, and the metal tie rods that ensure the spatial rigidity of the building. It was established that the masonry consists of brick laid on a lime mortar and contains areas of material loss and wall cracking. The walls in the northern part of the church are 2 m thick, while those in the southern part are 1 m thick. The wooden structural elements of the floor are almost completely destroyed, with remaining fragments in an emergency condition. The metal tie rods embedded in the masonry are partly cut and are made of square steel bars with a cross-section of 4×4.5 cm, as well as steel strips measuring 7–8×1.0–1.5 cm. The study was carried out with the support of the Department of Urban Planning and Architecture of the Chernihiv Regional State Administration. The obtained results have practical significance for the further development of conservation and restoration guidelines for the church and are of scholarly interest in the context of studying traditional structural systems and their adaptation to modern operating conditions.
Copyright (c) 2025 Mykola Korzachenko https://creativecommons.org/licenses/by-nc-sa/4.0
Defensive Urbanism in Modern Conflicts: The Case of Ukraine
This paper examines the influence of dense urban development on modern military conflicts, with a focus on Ukraine. The research highlights how urban form dictates the dynamics of combat operations, restricts troop mobility, and shapes tactical decisions. Historical models of fortified cities are considered, as well as contemporary examples, including Israel’s urban planning paradigm. The paper argues that Ukraine must adapt its state-building standards to incorporate defensive urbanism and resilient infrastructure. Recommendations for integrating urban planning with defense strategies are provided.
Copyright (c) 2025 Bohdana Rudakova, Ruslana Tryhub https://creativecommons.org/licenses/by-nc-sa/4.0
Results of the Inspection and Technical Condition Assessment of the Multi-level Load-Bearing Roof Structures of a Supermarket before the Installation of a RoofTop Solar Power Plant
A comprehensive detailed inspection and technical condition assessment of the multi-level load-bearing roof structures of a supermarket was conducted to determine the feasibility of installing photovoltaic elements on the building's roof. The work included analysis of technical documentation, visual and instrumental inspection of the building structures, and verification calculations. During the visual inspection, the structural features of the building and the technical condition categories of the building structures based on characteristic signs were established. During the instrumental inspection, non-destructive testing methods were used to determine the concrete strength and reinforcement parameters for reinforced concrete structures, and the steel strength and element thicknesses for the roof beam elements. Verification calculations established the load-bearing capacity of the reinforced concrete slab and metal roof beams. In the event of installing a rooftop solar power plant, a limitation on the building's service life was recommended. The research carried out underscores the necessity of conducting building and structure inspections when installing rooftop solar power plants.
Copyright (c) 2025 Ivan Matiushenko, Ruslan Kozak, Serhiy Gayda, Roman Shchupakivskyy, Zoya Kopynets https://creativecommons.org/licenses/by-nc-sa/4.0
Results of the Study of Mining and Processing Plant Waste for the Construction of Motor Roads and Railway Tracks
The pavement of technological motor roads consists of rock formations extracted from the quarry. With the current increase in the tonnage of quarry transport, the road pavement structure is also changing. On the other hand, the construction of the railway subgrade on dumps and stripping horizons of the quarry leads to increased operating costs for track repair and maintenance works. The relevant task is to investigate the physical and mechanical properties of rock materials from PJSC “Inhulets Mining and Processing Plant” (InGZK), to develop optimization measures and recommendations for the efficient use of these rocks for technological road pavements and the construction of railway embankments within the quarry and waste dumps of PJSC “InGZK”. The aim of this paper is to study the physical and mechanical properties of the rock formations of PJSC “InGZK” and to determine the grain-size composition of crushed stone produced from dense hard rocks. To determine the physical and mechanical properties of the rock materials of PJSC “InGZK,” the following were sampled: iron ore rock (migmatite) and associated dense rock types such as amphibolites, schists, granites, substandard quartzites, oxidized quartzites, oxidized jaspilites, and arkosic metasandstones. Experimental studies provided the physical and mechanical parameters and data on the grain-size composition of crushed stone from these rocks. Examination of the structure of amphibolites and schists from PJSC “InGZK” showed that these rocks have a dense texture, which provides high strength (1000 and 1200), and their mineral inclusions do not require additional beneficiation. The grains of crushed stone obtained from amphibolites and schists of PJSC “InGZK” have a cubical shape and high void content. This opens up the possibility of their use in the construction of roads and railway tracks, as well as in concrete and reinforced-concrete structures.
Copyright (c) 2025 Oleksandr Valovoi, Dmytro Brovko, Vitalii Afanasiev, Maksym Valovoi, Dmytro Popruha https://creativecommons.org/licenses/by-nc-sa/4.0
Cement-ash compositions with ash - fluidized bead removal
The results of studies of ash-fluidized bed removal by X-ray structural analysis, differential thermal analysis and IR spectrometry are presented. Ashes and ash-slags of the fluidized bed have slightly different properties due to the fact that in fluidized bed boilers the fuel is burned for several seconds longer than in traditional boilers. During this time, the dispersed part of the mineral component of the fuel has time to melt and transform into a glass phase, as a result of which their internal energy increases and they become capable of chemical reactions. The results of the research allowed us to establish that the fly ash of anthracene coal from domestic deposits when burned in a fluidized bed can be classified as medium-calcium and sulfate, which may hide the manifestation of hydration properties. The results of the IR spectrometry study confirmed the presence of calcium sulfate compounds of the gypsum and anhydride type in the fly ash composition. Sulfate minerals in the presence of aluminates and moisture can contribute to the formation of the ettringite mineral during the hardening of cement-ash compositions, which can contribute to the emergence of expansion stresses in cement stone. However, the study of cement-ash stone by X-ray structural analysis methods at the age of six months does not confirm the formation of ettringite. Testing of cement-ash compositions showed that the strength of the compositions at the vintage age is somewhat lower than that of cement stone. However, with a further increase in the hardening period, the rate of strength gain of the compositions is somewhat greater than that of cement stone.
Copyright (c) 2025 Rasul Akhmednabiev, Andrii Yalovehin https://creativecommons.org/licenses/by-nc-sa/4.0
Calculation of steel-reinforced concrete structures made of cold-formed steel profiles under biaxial loading
The aim of the work is to establish theoretical dependences for determining stresses at the extreme points of the cross-section of steel-reinforced concrete rod structures made of cold-formed steel profiles under biaxial bending loading. The steel part of the cross-section of the rod under consideration is a U-shaped profile, which is filled with concrete. At the first stage of manufacturing a prestressed rod, an initial bending of the steel part of the beams opposite to the operational one is created using mechanical jacks. During concreting of the U-shaped cavity and for the period of setting of the concrete to the design strength, the jacks under the steel beams remain. At the live load (third stage), the combined steel-concrete cross-section works together. In the concrete part, deformations develop from the undeformed (zero) state, while in the steel part, deformations of the normal cross-section are superimposed on the already existing deformations opposite to the operational ones obtained at the first stage of the combined structure during its manufacture.
Copyright (c) 2025 Oleksandr Drobotia, Hennadii Vakhnenko https://creativecommons.org/licenses/by-nc-sa/4.0
Restoration measures for foundations of metal silos on degraded loess soils
This paper examines the restoration of the serviceability of foundations of steel silos located on wetted and degraded loess soils. Based on the survey results and the analysis of the recorded deformations, a sequence of engineering measures is presented, including local repair of the ring foundation, restoration of the underground gallery, strengthening of the anchor connections and replacement of the pavement. It is shown that the applied set of repair measures ensures the stabilisation of the foundation structures and allows continued operation of the silos without a complete shutdown. The effectiveness of the implemented measures is confirmed by the results of geotechnical and geodetic monitoring conducted after the completion of the repair works.
Copyright (c) 2025 Oleksii Kichasov https://creativecommons.org/licenses/by-nc-sa/4.0
Flexural Behaviour of 3DCP Beams with Expanded Metal Sheet Reinforcement: Experimental Investigation and Numerical Verification
An experimental and numerical study of the flexural behavior of 3D-printed concrete (3DCP) beams reinforced with expanded metal sheet are presented in this paper. Four-point bending tests on beams of 3DCP were carried out in accordance with DSTU B V.2.7-214:2009, recording load–deflection curves and strains. The 3DCP showed an equivalent axial tensile strength 30–45 % lower than that of class C16/20 concrete. Correctly oriented sheet reinforcement increased failure load and flexural toughness by about 30–40 %, while a 3D FE model in LIRA-FEM reproduced ultimate loads within 5–10 % but underestimated stiffness.
Copyright (c) 2025 Petro Reznik , Dmytro Petrenko, Anton Volodymyrov, Dzhamaldii Alataiev https://creativecommons.org/licenses/by-nc-sa/4.0
Conditioning of boron-containing LRW with composite binders
Modern management of liquid radioactive waste (LRW) requires mandatory conditioning, which they practically carried out by cementing, most often with Portland cement. As an alternative to cementing, alkaline binders are used, which are chemically more stable, increase strength over time, and do not pollute the atmosphere with CO2. Most often, the basis of such binders is granulated blast furnace slag in combination with alkaline substances. As a development of LRW management, the direction of conditioning with composite binders we formed, which combines Portland cement and blast furnace slag in composition. Composite binders can take into account the positive properties inherent in the constituent components, while the properties will depend both on the physicochemical parameters and on the conditions under which the LRW is conditioned. The work shows that boron-containing LRWs with a pH > 12 and a total salt content of 60.2% can be conditioned with composite binders, with a ratio of granulated blast-furnace ground slag (particle size < 80 μm): PC-500 cement as 1:1 with a compressive strength > 3 MPa at a temperature of 55 - 60C. The amount of LRW (imitate) in the compound can be 35 - 40%. Alkaline substances included in the LRW composition they used as a binder hardening activator, without the addition of additional alkalis and liquid glass. Depending on the types of components involved: Portland cement, blast-furnace slag or composite binder, samples of compounds with a compressive strength of mainly > 10.3 MPa we obtained.
Copyright (c) 2025 Alla Rozko, Yuriy Fedorenko, Sergii Guzii https://creativecommons.org/licenses/by-nc-sa/4.0