Modern technologies and methods of calculations in construction

Basalt insulation is a natural «green material» for modern constructions

Ye.A. Bakulin — 2025-01-12

Modern economic conditions require materials not only with high-performance
characteristics but also with accessibility and relatively low cost. Thus, significant
potential for improving composite materials' characteristics lies in using inexpensive and
effective fillers, among which basalt and its derivatives undoubtedly stand out.
Basalt insulation materials, widely used for external insulation of wall panels, are
materials made of basalt fiber, which, in turn, is obtained from basalt. Although this is not
a new breed, its research is important for the development of new and innovative materials
not only in construction but also in other industries. Research into the natural origin of
basalt, as well as the chemical and mechanical properties of basalt fiber will help to
identify its strengths and weaknesses and compare it with existing basalt materials on the
market. Therefore, the development of new insulation materials with improved properties
compared to their predecessors remains a pressing problem.
Given the growing demand for energy-efficient and environmentally friendly
building materials, basalt insulation has great potential for further development and
application. Innovative production technologies and continuous improvement of material
properties contribute to their widespread implementation in the construction of new
buildings and the reconstruction of existing ones.
In the process of further research, it is necessary to analyze the technological
processes of production of modern insulation, which is key to identifying possible ways of
optimization and cost reduction. Studying production lines, their impact on product
quality, and the possibility of introducing new technologies, such as automation and the
use of new types of raw materials, can significantly increase production efficiency.

Modern photogrammetry technologies for object transformation on a 3D model

L.V. Haponova — 2025-01-18

The task of preserving architectural monuments, urban planning objects, and
engineering structures is prescribed in the Law of Ukraine on the Protection of Cultural
Heritage. Within the framework of the modern state of engineering structures and the
capabilities of modern software complexes, methods of preservation, visualization, and
maximum reproduction of objects in Ukraine are being developed. The model of the bridge
was chosen for the visualization studies of the structures. The available and accurate
method proposed in the work, which is easy to apply in practice, is the reverse engineering
digital photogrammetry method. The process is based on creating a three-dimensional
model from two-dimensional photographs using software. With its help, the user uploads
a set of photos to Autodesk servers and receives as a result a triangulated model of the
object with preservation of all real dimensions and with high-quality textures. The
obtained data was subsequently imported for further processing into another program of
this family - the Autodesk Inventor package. The Autodesk Inventor package has a
convenient interface and a large set of tools for modeling products. To demonstrate the
scope and level of processing of ReCap Photo, the options included in the application are
demonstrated in the work. The purpose of the article is to develop a sequence of scientific
research using digital photogrammetry. Setting the task. Based on the stage of evaluation
of priority processes, it is necessary to determine the key directions of research into the
digitization of objects and, based on the results of the evaluation, to propose a rational
model for the use of the reverse engineering method in the educational and scientific
activities of the Department of Computer Graphics. Highlighting previously unsolved parts
of the general problem. The Autodesk ReCap application processes DEM data. The
Сучасні технології та методи розрахунків у будівництві. Луцьк, ЛНТУ. 2024, Випуск 22
Modern technologies and methods of calculations in construction. Lutsk, LNTU. 2024, Volume 22
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obtained DEM can be used in Autodesk Revit, etc. Autodesk packages for: the design and
reconstruction of bridges; reconstruction of damaged housing stock; restoration of
damaged infrastructure and much more. The application supports almost all laser
scanning file formats. Clouds of points, in addition, can be edited arbitrarily - delete them,
copy, highlight, or even add survey points. As a result, it demonstrated the possibility not
only of creating technical documentation but also of reconstructing objects with millimeter
accuracy. Visualization and design make it possible to exclude possible errors. Due to the
identity of the spatial virtual model and the real physical object, the accuracy and quality
of the design increase. Digitization of monuments of architecture and cultural heritage of
Ukraine, establishment of a legislative framework, and preservation of UNESCO
monuments are important scientific and practical tasks. Conclusions and prospects for
further developments in this direction. The proposed algorithm makes it possible to use the
Autodesk software complex to preserve the cultural heritage of Ukraine. It is worth noting
that under safe conditions, the proposed algorithm for visualization of cultural heritage
objects will be used in peacetime.

Increasing wood strength through autoclave impregnation with linseed oil

S.S. Homon — 2025-01-18

Wood, due to its high strength characteristics, aesthetic and other parameters, does not lose its relevance in use until now. However, due to the influence of aggressive environments, biological and atmospheric adverse factors, the characteristics and terms of effective operation of wood are reduced. For more effective use of wood, it is necessary to improve its physical and mechanical characteristics.

One of the ways to improve the physical and mechanical characteristics of wood and prolong the terms of its effective operation under the influence of aggressive environments, biological and atmospheric adverse factors is modification by impregnation with an impregnate - a substance that, penetrating into the pores of wood, improves its characteristics. Materials for impregnation - impregnates have also been studied quite widely. Substances are used for impregnation, which are classified by origin. Each group of materials for impregnation has certain inherent advantages and disadvantages. Existing methods of autoclave impregnation of wood, which ensure the maximum depth of penetration of the impregnate and the speed of its drying (polymerization), have been analyzed. This paper presents the results of a theoretical analysis of methods and techniques for impregnating wood to enhance its compressive strength along the grain. The use of a linseed oil-based impregnating agent via a two-stage "pressure-vacuum" process is substantiated. Experimental studies were conducted on the impregnation of pine, birch, and spruce samples using the proposed agent and justified method. Based on mechanical tests of wood samples subjected to short-term compressive loads along the grain under rigid conditions, an increase in the strength of wood impregnated with the proposed agent and modification technology was determined.

Use of glue-laminated wood in industry

O.O. Homon — 2025-01-18

Wood is popular with developers, it is chosen for the construction of load-bearing structures, decoration, and creation of various interior items, small architectural forms. Natural material is undoubtedly good and environmentally friendly, but ordinary timber and boards have significant disadvantages: a tendency to change volume when humidity changes, drying out, deformation, and knots. These unpleasant consequences are practically excluded when using glued timber as a structural material and are used in various sectors of the world economy.

Glued timber is a material made by gluing layers of processed wood, where each layer is located perpendicular to the direction of the fibers. For production, mainly pine and spruce trunks are used.

The purpose of this article is to establish the scope of the application of glued timber and list its advantages compared to other traditional materials.

A detailed analysis of literary sources on the features of the use of glued timber has been carried out. The main physical and mechanical properties of glued laminated timber are characterized and analyzed in detail, and its structural schemes are given.

Wood, like other materials (metal, concrete, reinforced concrete, polymers), is exposed to various active aggressive environments. The scope of application of elements and materials based on glued laminated timber in various sectors of the economy is given, in particular, construction, woodworking, furniture, mining and quarrying, mechanical engineering, and others.

It has been established that one of the main advantages of glued laminated timber is its high mechanical strength and stability. Unlike solid wood, glued laminated timber is less prone to warping, cracking, or changing shape under the influence of temperature and humidity changes. This is achieved due to the fact that wooden lamellas are carefully processed and arranged so that the wood fibers alternate before gluing, which allows reducing internal stresses.

Features of microstructure organization decorative composites

O.D. Dovgan — 2025-01-18

The article proposes to use multi-level reinforcement of the structure of cement composites to improve and preserve the functional properties of decorative products. Strengthening the structure of the composite at all levels of its heterogeneities will provide the necessary resistance to various loads. The influence of discrete fibers of different lengths on the organization of the microstructure of dispersed systems was discussed earlier. The results of structural parameters of cement compositions presented in this paper are a continuation of previous studies.

To accurately describe the microstructure of the decorative composite and consider the relationships between its structural parameters, the method of experimental-statistical modeling was applied. Studies of 25 different compositions were carried out according to a 4-factor symmetrical plan. Processing of experimental data showed that the value of the water-cement ratio has a rather noticeable effect on the structural parameters of cement systems. A significant correlation between the indicators of cement systems has been identified. An analysis of the nature of damage to the surface of samples by cracks, internal surfaces of the section was carried out. It is confirmed that discrete fibers are able to actively participate in the processes of structural formation of building composites. Analysis of the data has shown that by introducing fiber, the uniformity of scattering of microdefects, internal stresses, etc. can be improved. The influence of composition factors on the structural parameters of the stone was evaluated using mathematical models. Visualization of local fields of properties in the coordinates of recipe factors made it possible to analyze the individual and synergistic effects of the influence of two groups of components on the formation of structural parameters of cement systems. It is shown that with rational ratios of composition factors, the structure of the capillary-porous space of the composite improves. The change in the number of microdefects in the structure of the material should affect the mechanical properties of the cement stone. It is planned to analyze the results of the study of the structural strength of the cement system.

The results of the inspection of the structures of the extension to the public building in Lutsk

S.Y. Drobyshynets — 2025-01-18

Information on the inspection results of the extension inspection to the public building is presented. The results of the visual survey are provided. The defects identified during the inspection are described. The technical condition of the load-bearing structures is analyzed. Measures to restore the technical characteristics of the inspected structures are proposed.

Analytical solutions of simplified equations оf motion in ballistic problems of a material point

Andrey Zadorozhny — 2025-01-18

The paper substantiates the application of Lambert's special function for solving ballistic problems of a material point taking into account the resistance of gaseous (air) medium. Analytical solutions of simplified equations of motion for gentle and steep (relative to the horizon) trajectories are given. A comparative analysis of the results obtained using the Lambert function with the classical results obtained by Didion is carried out for the calculation of a hollow (hovering) flight trajectory. For the case of steep (relative to the horizon) flight trajectories of a material point, analytical solutions of the problem of external ballistics in quadrature have been obtained for the first time. The results obtained in this paper can be used to refine and improve the existing engineering methods for calculating the trajectories of motion and its main characteristics in the problems of external ballistics of a material point, when the nonlinear (proportional to the square of the velocity of motion) resistance of the medium is taken into account, in the problems of modern construction production, describing the processes of shotcrete concrete mixtures, as well as for the identification of the main parameters of motion, in particular, the coefficient of sailing.

Ensuring the functioning of engineering, transport networks thanks to the strengthening of damaged reinforced concrete columns of their structures

L.M. Ksonshkevych — 2025-01-18

The reliability of the functioning of engineering and transportation networks largely depends on the technical condition of their structural facilities. For example, in many design solutions for pumping stations in water supply, sewage, and heating networks, significant attention is paid to the compact use of the internal space of technological rooms. This is due to the need to accommodate large-sized technological equipment in these rooms, as well as to install a complex pipeline system in accordance with the operational scheme of the pumping station. Therefore, the use of columns in such spaces aligns well with the requirements for the reliable operation of engineering networks because it: ensures the technological requirements for the operation of the pumping station; facilitates the relocation, repair, and replacement of large-scale technological equipment and the installation of complex pipeline systems during modernization, reconstruction, or restoration after damage, while considering changes to the system's operational scheme. In this regard, the mechanical properties of concrete made with ordinary Portland cement, microsilica, and the SP-1 superplasticizer have been studied for its potential use as a high-strength material in reinforcing the load-bearing concrete structures, specifically the columns of engineering structures within engineering and transportation networks. These include pumping stations in water supply, sewage, and heating networks; district heating plants; bridges; and pedestrian overpasses. The concrete mix was developed to construct reinforced concrete jackets for strengthening damaged column structures. This technology has significant advantages for constructing column structures in terms of their resilience during shelling, particularly in terms of execution speed, strength, reliability, and protection from various external impacts during such events. When performing research, first, mixing water, SP-1 additive, Portland cement and microsilica (from 0 to 10 %) were sequentially introduced, later they were combined with a dosed amount of quartz sand and granite crushed stone in an ordinary concrete mixer. The compressive strength of concrete was determined according to DSTU B V.2.7-214:2009. Experimental data showed that by varying the selected factors, it is possible to increase the strength of concrete in the initial period when it is doubled in compression.

Cyclic Loads and Fatigue Analysis of Steel Structures of Frame Mine Headframes

Volodymyr Kushchenko — 2025-01-18

The structures of mine headframes are classified as lifting and transport mining structures, which fall under the highest responsibility class. Most mine headframes in Ukraine have been in operation for extended periods, subjected to intense cyclic dynamic loads and aggressive environmental conditions. Consequently, there is a need to assess the residual life of these structures and ensure they meet the required service life in terms of fatigue strength. Currently, fatigue analysis for mine headframe structures is not covered by existing standards, as there is no established methodology for determining typical load cycles. Based on an analysis of the key stages in the technological cycle of mine hoisting installations, it is proposed to define a typical load cycle as the sequential application of loads from two design scenarios: the design scenario of the maximum total tension force in the hoisting rope branches, and the design scenario of the minimum total force in the hoisting rope branches. These scenarios, combined with constant and long-term loads, define the maximum and minimum stresses in the load cycle for the critical sections of the structures. This methodology accounts for dynamic forces arising from forced oscillations of the lifting vessels when calculating the cyclic forces in the hoisting ropes. For the characteristic structure, the types of structural elements and critical sections for endurance analysis are identified in accordance with the provisions of the standard methodology. Through the analysis of the stress-strain state in the critical sections of the mine headframe structure, the characteristics of dynamic stress cycles were determined, and a fatigue strength calculation was performed. The analysis revealed a limited fatigue life for the main beams of the headframe structure. The proposed engineering method for analyzing the fatigue strength of mine headframe structures can be applied both in the design of new structures and in the development of systems for monitoring the technical condition of operating mine headframes.

Strength and deformability of structural modified wood of spruce and ash during operation in water environment

O.V. Matviiuk — 2025-01-18

Structural wood is operated in various aggressive environments. It is most affected by alkaline, aqueous, saline, and acidic environments. At the same time, wood-based materials and elements under such operating conditions can operate under various types of loads. The most common are the operation of solid, glued, and modified wood under axial compression and tension along the fibers. In this article, we will be interested in the operation of structural modified wood under axial compression along the fibers under short-term loads during operation in an aquatic environment. The purpose of this article is to establish the main strength and deformation parameters in the subcritical and postcritical stages of operation of a composite material when operating in an aquatic environment.

The methodology of experimental studies of modified and unmodified 40-year-old structural wood of spruce and ash by axial compression along the fibers under normal operating conditions and in an aquatic environment is presented. According to the results of the experiment, histograms of the dynamics of changes in the main characteristics of strength and deformability were constructed. It was established that the influence of the aquatic environment significantly reduces the temporary ultimate strength of wood and the modulus of elasticity, increases the relative critical and residual deformations compared to the indicators at a standard humidity of 12%. It was found that the modification of wood with the polymer composition Silor increases the maximum stresses and the modulus of elasticity; reduces the relative critical and residual deformations compared to the indicators at a standard humidity of 12%. The obtained composite materials based on spruce and ash wood and the polymer composition Silor are stable during operation in aquatic environments and do not deteriorate the main strength and deformability properties.

Reconstruction and landscaping of a park in Ratne village

Y.A. Мelnyk — 2025-01-18

This article presents a conceptual framework for the reconstruction and enhancement of the Ratne village park. The primary objective is to enhance the landscape environment by augmenting the appeal of each functional zone and ensuring the provision of comfortable conditions for visitors to reside in the green and coastal areas of the park. In consideration of the desires of the village residents and the extant circumstances, the area designated for reconstruction and improvement was delineated into functional zones, comprising the entrance, parking, greenery, cultural and public gatherings, commercial, entertainment (sports grounds, children's play area), memorial and coastal zones. The division was made on the basis of the intensity of use and purpose, thus ensuring an integrated approach to the organisation of space.

The design concept of the park entails the integration of natural and infrastructural elements to create a space that is responsive to the needs of all age and social groups. Particular attention is paid to ensuring accessibility and safety for visitors, which is achieved through the implementation of a well-developed infrastructure. In particular, the project provides for the arrangement of paved paths, the installation of rubber-coated bicycle routes, and the placement of modern benches and lighting systems. A barrier-free environment has been created for individuals with limited mobility, thereby facilitating their comfortable access to all areas. The park's design incorporates spaces for children's and sports activities, with the objective of promoting a healthy lifestyle. Additionally, a memorial area has been established in accordance with the community's request, serving to honour the memory of fallen heroes and residents of the village.

The park's landscaping was designed with the objective of creating a harmonious combination of tall trees, bushes and ornamental shrubs. Significant effort was made to conserve the existing natural landscape and to introduce new species of trees and shrubs, with a particular emphasis on local flora.

The project will result in the creation of a multifunctional park that incorporates both active and relaxation areas, cultural and memorial elements, and the natural beauty of the surrounding area.

Influence of modifiers on the structural and physical characteristics of rigid polyurethane foam

О.А. Mikulich — 2025-01-18

Experimental studies of the influence of modifiers on the structural and physical characteristics of rigid polyurethane foams were carried out in this work. The article analyzes the structure and properties of polyurethane foam material. The methods of manufacturing PPU materials are presented with an assessment of the advantages and disadvantages of each method.

Rigid polyurethane foams were manufactured by pouring into open molds. The main components for obtaining foam were polyol (component A), which included a foaming agent, and polyisocyanate (component B). We used different weight ratios of polyol and polyisocyanate for preparing experimental samples. As a viscous modifier siloxane rubber was used. As a granular modifier of two types swollen perlite of volcanic origin was used.

It is shown that the modifying additives of siloxane rubber and granular perlite enter the structure of polyurethane foam heterogeneously, forming an independent phase. The microstructure of the test samples was characterized, their morphology was described, the average density was determined, and the porosity of the modified foam material was investigated. It was established that the addition of silicone into the polyurethane system leads to a change in the morphology of the pores and the emergence of a mixed type of porosity. For some samples, it was the presence of both closed and open pores. In the case of using as a modifier expanded granular perlite, the foam's porosity does not change and all pores in obtained foam are closed.

Further studies of the properties of PPU modified with expanded perlite in the direction of practical application as a heat-insulating material were described.

Research of neglected buildings in Volyn region and assessment of their adaptation potential for community needs

I. O. Parfentieva — 2025-01-18

With the current rapid population growth in the Volyn region, the need for the construction of a larger number of buildings is growing. However, cities are quite densely built up these days and it is very difficult to find vacant land for construction.

We must to pay attention to old abandoned buildings that have not been used for many years to provide the population of the Volyn region with new premises for commercial, industrial and other purposes,. Very often, the structures of such buildings are in normal condition, and the building can be used after reconstruction or major repairs. Using old buildings as a foundation for new ones is one of the most environmentally friendly and economical ways to build. People should make the most of urban areas and prevent areas from remaining unused. In addition, reconstruction takes much less time to implement than new construction. This factor contributes to a faster commissioning of the facility.

It is necessary to conduct a technical inspection of old buildings to check the load-bearing structures and confirm their condition, which meets the requirements for strength and reliability. First of all, load-bearing and enclosing structures are checked. It is also necessary to take into account the condition of non-capital structures for budget planning.

This article examines the problem of old buildings without exploitation, examines individual buildings, analyzes their technical condition, and draws conclusions about the possibilities of further exploitation. The examples given show only a small part of the abandoned buildings that can get a new life.

One building in the city of Lutsk and one building in the village of Zhuravychi were selected for the research. Both buildings have not been used for more than 15 years, but their structures are in good condition and suitable for use.

Modular systems: concept, energy efficiency, and functional capabilities in the context of reconstruction

R.V. Pasichnyk — 2025-01-18

The article examines the concept, energy efficiency, and functional capabilities of modular systems in the context of reconstruction. Modular construction is based on the principles of factory production of modules, ensuring high precision, quality, compliance with standards, modular versatility, rapid assembly, and design flexibility. The modular approach allows buildings to be easily adapted to individual needs. Within this approach, various types of modules are used, each fulfilling specific functions: facade modules, structural modules, engineering modules, and functional modules. Modular systems have clear advantages over traditional reconstruction methods. They ensure speed and quality of work, reduce costs, and have a positive environmental impact. In the context of post-war recovery, these characteristics make modular systems the optimal choice for fast and sustainable reconstruction of the housing stock. Strengthening load-bearing structures and using replaceable modules for damaged walls and floors are key technologies in restoring damaged buildings. These technologies provide a quick, cost-effective, and high-quality return of buildings to operation, meeting modern construction and safety requirements. The integration of modular systems enables efficient solutions for reconstruction tasks while minimizing disruption to residents and reducing resource consumption. Modular systems are among the most effective approaches to building reconstruction in post-conflict conditions. They not only ensure rapid and high-quality restoration but also contribute to improving the energy efficiency of buildings. Considering current requirements for reducing energy consumption, modular solutions allow for minimizing energy losses and providing comfortable living conditions for residents. One of the key advantages of modular systems is the ability to integrate insulation materials directly into facade modules. This significantly enhances the energy efficiency of buildings, especially in cases of reconstructing old concrete buildings that typically have low thermal insulation properties. In modern conditions of housing stock reconstruction after military actions, it is essential not only to restore damaged buildings but also to ensure their environmental sustainability. An ecological approach involves minimizing environmental impact through the use of environmentally friendly materials, recycling damaged structures, and reducing the volume of construction waste. In this context, modular systems play a crucial role as they combine efficiency with environmental care. Modular systems provide extensive opportunities for improving the design and aesthetics of buildings. The use of diverse materials, the creation of harmonious appearances, and integration into urban environments make such systems the optimal solution for reconstructing the housing stock under modern conditions. They not only meet aesthetic demands but also contribute to the creation of a comfortable and functional urban space.

Level of heat loss of heating systems in existing buildings

O.A. Pakholiuk — 2025-01-18

Energy consumption in buildings is largely dependent on losses through the building envelope and through engineering systems.

It is known that the largest losses in engineering systems occur at the stage of transportation of energy resources to the building, as well as in places where they are located in unheated premises. Therefore, it is very important to provide high-quality, full-fledged insulation of engineering systems to minimize energy losses.

A significant number of heating systems currently operating in our buildings were designed and commissioned more than 30 years ago. The materials and thickness of insulation used at that time differ significantly from the current requirements set out in Annex B of the relevant DBN.

It should also be noted that the condition of the pipelines themselves is quite different. In some buildings, although not insulated, they are well maintained, painted, and protected from moisture. In others, the pipelines are in disrepair, the walls are covered with rust, leaking in places, and can lead to an emergency.

Comparing the dependence of heat loss changes in insulated and non-insulated pipelines, we can note the similarity of their character in the form of a polynomial of degree 3.

It is also worth noting that the heat loss of pipelines with outer diameters of 50 mm or more increases sharply (in uninsulated pipelines) or gradually (in insulated pipelines).

During the heating period, the level of losses corresponds to the temperature of the heat carrier in the system, and therefore to the ambient temperature. For pipelines of other diameters, we observe a similar dependence.

Regardless of the diameter of the pipelines, losses in non-insulated pipelines significantly depend on the temperature of the heat carrier and fluctuate within significant limits. Losses in insulated pipelines fluctuate within insignificant limits. The highest losses will occur in January, and the lowest - in April. We do not take into account the months when there is no heating.

An average heating system in a five-story building with damaged or missing insulation will lose UAH 378,294.3 during the heating season compared to a well-insulated one. On average, buildings that have been in operation for a long time can usually have localized damage or lack of insulation in the amount of up to 30% for various reasons. In this case, the cost of losses in such systems will amount to UAH 113488.3.

Improvement of the method for determining the necessary heat transfer resistance of building enclosures

V.A. Pashynskyi — 2025-01-18

The study was carried out with the aim of developing a method of more precisely determining the required heat transfer resistance of building envelope, taking into account the climate conditions of their operation and permissible heat losses. The methodology is based on the dependence of heat loss on the heat transfer resistance and the mutual relationship between the number of heating degree days determined for different values of the air temperature in the premises.

The administrative-territorial zoning of Ukraine by the number of heating degree days at an indoor air temperature of +20°C is based on the published results of meteorological observations at 367 weather stations located at an altitude of up to 400 m above sea level. For each of the oblasts of Ukraine, Autonomous Republic of Crimea, and separately for the South Bank of Crimea, regional values with zoning coverage of 0.9 and 0.95 are set. In order to reduce the spread of data across the territory, the Odesa region and the Southern coast of Crimea are divided into groups of administrative districts.

The effect of using the proposed method of determining the heat transfer resistance of building envelopes is analyzed on the example of the walls of residential buildings. The walls are designed for the climate conditions of 24 regional centers of Ukraine, Simferopol, the capital of Crimea, and Yalta, located on the southern coast of Crimea. The results of the experimental design showed that when designing according to DBN B.2.6-31:2021, the values of the required heat transfer resistance of the walls within the territory of Ukraine differ by only 14%, and the difference in heat loss through the designed walls in different cities reaches 89%. When designing according to the proposed method, the values of the required heat transfer resistance of the walls within the territory of Ukraine differ by 2.17 times, due to which the territorial variability of heat losses decreases to 20%.

The proposed method contributes to the equalization of heat losses through the building envelopes on the territory of Ukraine due to the differentiation of the necessary heat transfer resistance of the envelopes by region. The significant influence of the permissible amount of heat loss on the required value of the heat transfer resistance of the envelopes requires the determination and normalization of the permissible heat loss through the building envelopes of various types in buildings of various purposes.

Determination of plasticity of the cast asphalt mixture by torque value

Y.І. Pyrig — 2025-01-18

Mastic asphalt concrete, unlike other types of hot asphalt concrete, has a long history and a wide range of applications in both industrial and road construction. The peculiarities of the composition of mastic asphalt mixtures and asphalt concrete are the reason for the use of non-standard quality indicators, which include, in particular, the indicator of technological plasticity. Many different methods have been proposed to determine the technological plasticity of mastic asphalt mixtures, but there is no single generally accepted method. Each country uses certain methods to assess the plasticity (mobility) of mastic asphalt mixtures during their manufacture and placement in pavement layers. The aim of the study is to review the method for determining the plasticity of mastic asphalt mixtures based on the establishment of the value of the mixer torque during mixing of the mixture at technological temperatures. To achieve this goal, a corresponding device was manufactured at the Department of Road Construction Materials of Kharkiv National Automobile and Highway University and the plasticity of mastic mixtures was experimentally determined with an assessment of the sensitivity of this method to the parameters of the mixtures. During the first tests, the advantages and disadvantages of this method and the device were identified. A significant advantage is the ability to conduct the entire test cycle of one mixture at different temperatures without the need to unload/load the mixture into the mold during the test at each temperature. This, in turn, significantly reduces the test time. A certain disadvantage of the method is its subjectivity and relatively low reproducibility of the results. This disadvantage can be corrected by replacing the manual rotation of the shaft with mechanical rotation using a motor with a constant rotation speed. The experimental verification of this method of determining plasticity was carried out on a mastic asphalt mixture of the LABS-10 type, made with three concentrations of bitumen. It was determined that the experimentally obtained temperature dependences of the torque are described by power functions of the second order and are characterized by determination coefficients not lower than 0.985. During the experimental verification of the manufactured device, its advantages and disadvantages were identified, based on the analysis of which ways to improve the design of the equipment were proposed. It has been established that this method (after making improvements to the design of the device and changes in the test methodology) can be recommended for use in production laboratories of the domestic road industry to design the composition of mastic asphalt mixtures and check their quality.

Design of multi-story industrial buildings taking into account resistance to progressive collapse in the SCAD++ PC

S. Rotko — 2025-01-18

Progressive collapse is a process in which local damage to a structure leads to a chain reaction of destruction that spreads to the entire building or a significant part of it. This phenomenon can have catastrophic consequences, so understanding its causes is extremely important for ensuring the safety of buildings and structures.

The most common causes of progressive destruction are external influences caused by natural or man-made factors. Traditionally, the highest percentage of such destruction is occupied by brittle destruction (for example, during fires) and loss of stability (due to seismic effects, explosions, impacts, etc.), less often by fatigue and ductile destruction.

To prevent progressive destruction when making design decisions, it is necessary first to reduce the level of risk by directly calculating such risk. It is important to use such calculation and design solutions that will make possible damage impossible (general strengthening of the entire building, local strengthening, interconnection). Structural interconnection of elements (or structural continuity) is also noted among the methods of general or local strengthening.

Progressive collapse usually begins with the loss of stability and strength of one or more vertical structural elements of a building or structure (columns or pylons). For the building to withstand, it is necessary to provide an alternative path for transferring the load to other structural elements. Adjacent elements must be designed to resist these redistributed loads (those that the collapsed structure would have to bear). Otherwise, collapse will inevitably occur, and further load redistribution will occur until equilibrium is reached. This in turn will lead to partial or complete collapse of the building or structure.

Protection against progressive collapse involves computer modeling using finite element and limit equilibrium methods. It allows you to create full-fledged models that almost completely correspond to the response of the building to local destruction.

The work performed a calculation of a multi-story building of the production building of a compound feed plant with a steel frame for progressive collapse. The calculation was performed using licensed software - SCAD Office - an integrated system for strength analysis and design of structures of the MSE.

Analysis of the effectiveness of using high-strength concrete in compressed elements of monolithic frame buildings

S. Rotko — 2025-01-18

Traditionally, reinforced concrete is the most common material for constructing multi-story civil buildings. Modern construction is characterized by a significant increase in the number of storeys of buildings and at the same time a significant increase in the complexity of architectural solutions. Therefore, high-strength concretes are quite popular materials, especially in implementing ambitious architectural projects, where it is necessary to ensure high strength and reliability of structural elements.

The issue of increasing the strength and durability of concrete has long been on the agenda of scientists around the world. Many of them believe that the main method of improving the physical, mechanical construction, and operational indicators of concrete is to ensure the quality of its micro- and mesostructure, i.e., high density, impermeability, and minimal cracking.

It has been proven that the use of high-quality aggregates, highly active cement, and a low W/C ratio is the simplest and most economical way to obtain high-strength concrete using traditional manufacturing technology.

Among the advantages of using high-strength concretes are higher early strength, the possibility of early stripping (and therefore, earlier commissioning of the facility), increased load-bearing capacity, reduced costs for formwork due to a reduction in the cross-section of structural elements (respectively, a reduction in the weight of the latter, and therefore, the load on the structures below). This, in turn, will contribute to a reduction in the volumes of concrete and reinforcement, i.e., the installation mass of the elements, and, accordingly, a reduction in transport costs for the delivery of materials. Important advantages are also higher density, water and gas impermeability due to a reduction in capillary pores, increased resistance to chemically active substances; high corrosion resistance, and therefore, protection of reinforcement; and reduced costs for formwork.

The paper studies the feasibility of using high-strength concrete for the manufacture of vertical elements operating in compression - columns and pylons of multi-story residential buildings.

To study the effectiveness of the use of high-strength concrete, a monolithic 13-story frame residential building with commercial premises located on the first floor was taken. The calculation was carried out in the MONOMAKH-SAPR PC using the finite element method (FEM).

The study found that replacing concrete in columns of class C20/25 with concrete of class C50/60 allowed a total economic effect of 223,693 thousand UAH due to the reduction in the cross-sectional dimensions of the columns and the reduction in the cost of reinforcing steel. The savings on materials amounted to 17.9%. It is also important that the useful area of the building increased when the cross-sections of the columns were reduced, which will also have a significant economic effect.

Therefore, we can conclude that it is economically feasible to use high-strength concrete for columns of multi-story buildings, especially in high-rise construction.

Holovan's House: determination methodology of measures for the storm drains sewerage of buildings and territory

S.V. Synii — 2025-01-18

Under the general understanding of the "Holovan's House" complex, this article examines the buildings and structures along with the land on which they are situated. The construction of the sculptor's own two-story brick residential house, which became the main element of the complex and gave it its name, was started by the renowned contemporary Ukrainian sculptor Mykola Holovan (1943 – 2022) in the 1980 s. Today, the history of the Holovan's House complex spans over 40 years. One of the reasons for this prolonged construction is the sculptor's creative approach, as he handcrafted various sculptural elements throughout the building process, aiming to incorporate them into the structural solutions for the house's enclosing constructions. These include lintels above the entrance doors, numerous decorative elements on the exterior walls, and the roof. The artist also applied this principle when arranging the house's storm drains sewerage, using handmade sculptural elements. Overall, most of the construction work on the buildings and structures, improvement of the territory was carried out manually by the sculptor. For Mykola Holovan, this was a continuous creative process. However, this also became one of the reasons for the partial incompletion of the Holovan's House complex, with the sculptor expressing in interviews his hope that his descendants would complete the work.

The preliminary review of the Holovan's House complex revealed that the partial incompletion of certain construction works related to the installation of the storm drains sewerage for the buildings, structures and territory would have a negative impact on the technical condition of the residential house. Specifically, one of the reasons for the damage to the enclosing structures of the house, identified during the inspection, is the negative influence of the existing storm drains sewerage. In this context, the article justifies the methodology for determining measures to install the storm drains sewerage for the buildings, structures and territory. This methodology is based on the belief that a methodologically sound approach to making technical decisions in construction, reconstruction and restoration will provide protection against the gradual damage and deterioration of the house's structures.

Acid numbers – a criterion for the suitability of bitumen for wearing courses for slurry surfacing

Iu. Sidun — 2025-01-18

The article explores the dependence between the acid number of bitumen binders and the cohesive strength of Slurry Surfacing. To produce cationic bitumen emulsions and Slurry Surfacing, paraffinic binders from the Polish company PKN Orlen and domestic bitumen from PJSC Ukrtatnafta (Kremenchuk Refinery) were tested. Naphthenic bitumen was sourced from the Swedish company Nynas, the world’s largest producer of naphthenic bitumen. To create the cationic bitumen emulsions for Slurry Surfacing, bitumen, a cationic emulsifier (amine-based), hydrochloric acid, and drinking water were used. Emulsions were prepared in a laboratory setting using a colloidal mill. Slurry Surfacing was designed and tested following the technical bulletins of the International Slurry Surfacing Association. In addition to emulsions, the Slurry Surfacing mix included a granite crushed stone-sand mixture (0-10 mm fraction), water, portland cement, and a decomposition regulator in the form of a 10% emulsifier solution.

It was found that high-acid bitumen binders are optimal for Slurry Surfacing in terms of cohesive strength. The study confirmed that naphthenic bitumen exhibits significantly higher acid numbers than paraffinic bitumen. Additionally, Slurry Surfacing compositions based on naphthenic and paraffinic bitumen require different amounts of decomposition regulator to achieve the desired decomposition time. Specifically, formulations with naphthenic bitumen require 0.5 parts more degradation agent than those with paraffinic bitumen. Despite this increased need for degradation agent, the rate of cohesive strength gain in Slurry Surfacing samples with naphthenic bitumen is 12 times higher than that of unmodified paraffinic samples and 10 times higher than that of polymer-modified paraffinic samples.

Influence of rules on the road surface on traffic safety during maneuvers by vehicles

R.V. Smolianiuk — 2025-01-18

The influence of different factors leads to rut formation on roadways. Ruts not only diminish the aesthetic appearance of the pavement but also cause danger to vehicles. It is obvious that during precipitation water accumulates in ruts potentially leading to hydroplaning and loss of vehicle stability. On dry pavements, rutting can also be hazardous when a vehicle leaves its lane to perform an overtaking maneuver or other maneuvers. Ruts cause additional suspension oscillations, body sway and loss of wheel contact with the pavement, which negatively affects traffic safety. In 2022, Ukraine introduced rut depth requirements for roads in operation for the first time. However, it must be understood that non-compliance with these regulatory standards does not immediately result in resolving such issues through repair work. The reasons are evident – a significant lack of funding currently exists and is likely to persist for quite some time. From the moment of problem identification until its resolution, the road will remain in operation. This article presents the results of a research evaluating the effect of rut-affected pavement on a vehicle performing a maneuver. For this purpose, pavement models with varying rut parameters were created within the following ranges: rut depth from 0 mm to 100 mm, rut width from 300 mm to 1500 mm and rut base from 1700 mm to 2100 mm. The cross-slope of the roadway was set at 25‰, with a dual-slope cross-section profile. Surface modeling was conducted using RutGenerator software developed by KhNADU. The Kristy model was chosen to calculate the parameters of lane-changing maneuvers as it provides the most accurate representation for modern vehicles. The primary distinction of this methodology from Illarionov's approach lies in limiting the maximum lateral lane displacement based on the vehicle's sideslip condition, rather than its overturning condition, which better aligns with the characteristics of modern vehicles. Using RutGenerator software, vehicle trajectory simulations during a lane-change maneuver were carried out for speed ranges from 50 km/h to 130 km/h. Basing on the calculated trajectories, pavement profiles along the vehicle's path during the maneuver were constructed. The resulting set of profiles was analyzed using the ProVal 3.51 software package developed by The Transtec Group. The developed methodology can be used to plan measures to ensure road traffic safety in areas with rutting. Such measures may include speed limits, restrictions on overtaking and others.

Determining the Location of the Pavilion and Recommendations for Designing Stops for Route-Based Public Transport

S.Yu. Timkina — 2025-01-18

The article examines and provides recommendations for the optimal placement of pavilions and the design of stops for route-based public transport. The research reveals that the positioning of pavilions has a significant impact on the effective utilization of the stopping platform, the capacity of stops, and the ease of passenger service. The interaction between pedestrians and passengers waiting for transportation and vehicles arriving at the stop is looked at.

Experimental data showed that vehicles usually stop opposite the pavilion, regardless of location. It leads to uneven use of the stopping platform, particularly when a pocket is absent. A formula is suggested to determine the optimal stopping point of the vehicle based on the location of the pavilion. These results demonstrate a strong linear relationship between these parameters (the coefficient of determination is 0.8962).

It's best to put the pavilion 3/4 of a mile away from the starting point of the stopping platform to make the most of its length. Furthermore, the geometric parameters of the stops are examined, particularly the width of the boarding platform, which should be determined considering passenger density and waiting time. We figured out the optimal parameters for pockets and the number of parking spaces for urban streets with varying traffic intensities.

The findings provide recommendations for the engineering and planning organization of route-based transport stops, with the aim of enhancing their operational efficacy and enhancing passenger service quality.

Increasing the durability of pavement on bridge structures through the use of thin-layer coatings

O.V. Fedorenko — 2025-01-18

Road pavement is a key structural element for ensuring the safety and comfort of vehicles, in particular due to its flatness, low noise level and roughness, which guarantees the proper coefficient of adhesion to the tires of vehicles while driving. However, it should be noted that during operation, such a coating is easily exposed to negative factors that lead to its premature deformation.

In today's conditions of intensive development of transport infrastructure, the use of materials capable of ensuring the durability and reliability of pavements on roads and bridges is of particular importance. One of these materials is methyl methacrylate-based mixtures, which are becoming increasingly popular due to their exceptional performance properties. Methyl methacrylate mixtures provide high wear resistance, chemical resistance, fast curing and the ability to be used in various climatic zones. They also demonstrate excellent adhesion to various types of surfaces, making them particularly valuable for repairing and overlaying bridges and other complex structures.

However, in order to maximize the potential of methyl methacrylate-based materials, it is necessary to comply with the requirements for the quality of the initial components and the technology of manufacturing mixtures. Inadequate quality of raw materials or violation of technological processes can lead to deterioration of the pavement performance, its premature wear and the need for frequent repairs.

Asphalt concrete mixtures based on methy methacrylate resin with different types of aggregate (sand, screenings) were tested. The main task was to determine the physical, mechanical and thermo-rheological properties of the tested samples. The obtained results of the studies indicate the effectiveness of the use of asphalt mixtures based on methomethacrylate for use as a thin-layer pavement on road bridges.

Modern materials for sealing seams in road surfaces and structural elements of automobile roads

O.O. Fomenko — 2025-01-18

Motorway structures are constantly in direct contact with natural and climatic factors. The article is devoted to the problem of providing waterproofing and vapor barrier protection against the effects of water seepage or anti-icing salt solution. The question is raised that in the current conditions of modern construction, not always proper attention is paid to the issue of high-quality waterproofing coating, which, in turn, is one of the most important components for preserving durability, for ensuring the strength and reliability of the main constructions of transport structures. In addition, in this article, the authors consider various types of waterproofing materials and road equipment for installing waterproofing. Rolled materials, liquids, mastics, pastes, and powders can be waterproofed. Waterproofing mastics and pastes differ from sealants in that they contain a significant amount of filler and their main purpose is to protect the material from moisture. An effective option for modern waterproofing of cracks and deformation joints of concrete coatings is the use of cold-applied thermosetting sealants, especially silicones. They have good adhesion, and a small modulus of elasticity, so it is advisable to recommend them for filling narrow cracks. Such sealants are acceptable for cracks that have a wetted surface. Cold sealants are used at air temperatures above 5 °C. It is advisable to use the two-component, bitumen-latex, highly elastic waterproofing material FLEXIGUM-HP on fairly responsible structures, which is distributed on the treated surface by cold spraying with special equipment. In foreign countries, the use of sealing deformation joints with rubber templates of various profiles, in particular with polychloroprene silicone gaskets, has expanded. An analysis of the factors that determine the quality of the installation of waterproofing of deformation joints of road surfaces was performed.

Modeling of oscillations of the undercarriage suspension system of crawler load-lifting machines

Yurii Chovnyuk — 2025-01-18

This paper considers longitudinal vibrations of spring elements of the caterpillar mover and undercarriage support system of crawler load-lifting machines within the framework of the discrete-continuum model. A comprehensive analysis of the wave processes arising during the caterpillar mover operation is carried out.

Crawler belts of modern hoisting machines are spring-closed chains consisting of movable links with lugs (tracks) of relatively small mass, connected by rigid elements - fingers. By design, the pins can be covered with wear-resistant rubber when pressing into the lugs of the tracks [1]. The effect of the elasticity of caterpillar belts leads to the fact that when the caterpillar machine moves, some parts of the caterpillar mover acquire the properties of oscillating systems in which dynamic processes of wave type are maintained.

One of the effective ways to eliminate the reflected waves on the boundaries of adhesion of caterpillar belts with the teeth of drive wheel crowns is the introduction of a tensioning mechanism with elastic-dissipative elements into the design of the running gear of the caterpillar. The provision of uniform tensioning of the caterpillar belt (using the tensioning mechanism) allows for the exclusion of the possibility of resonance occurrence as a result of the addition of the incident and reflected waves. In this way, it is possible to achieve a uniform distribution of dynamic loads on the teeth of the drive wheel gears as well as in other units and parts of the crawler.

Longitudinal spring oscillations of caterpillar belts are considered a superposition of two weakly damped waves simultaneously moving toward each other. It is theoretically presented that a significant reduction of caterpillar belt oscillations can be achieved by selecting the parameters of a damping device that eliminates reflected waves at the tension and sagging boundaries of the caterpillar belts. Estimated parameters of fixation of caterpillar belts on toothed crowns of driving wheels and boundaries of their final fixation, from which waves are not reflected, are presented.

Analysis of snow removal equipment and measures aimed at improving the winter maintenance of highways

O.P. Shymchuk — 2025-01-18

The article analyzes the existing snow removal equipment for winter maintenance of highways and city streets. An auger snowplow is proposed to ensure snow removal from the roadway, loading it into car bodies and taking it off the road.

During operation, highways are subjected to constant loads and exposed to atmospheric influences. Weather conditions and destructive transport actions worsen the operational properties of the road as an engineering structure while reducing the efficiency and safety of road traffic.

The most important factors in the winter period that affect the safety of road traffic and the speed of movement of vehicles are the slipperiness of the surface and snow accumulation (when snow accumulates on the roadway). These factors lead to a decrease in the coefficient of adhesion of car tires to the road surface and an increase in the probability of skidding. As a result, the braking distance increases, traffic becomes more difficult, and the probability of traffic accidents increases.

The winter maintenance of highways includes a set of works performed by road organizations with the aim of ensuring safe and uninterrupted traffic in winter, in particular, snow removal, combating slippery conditions, and clearing roads.

Winter road maintenance is an expensive process, as it is quite often difficult to predict weather conditions.

Road cleaning measures affect their service life and safety. Therefore, the proper execution of works and the use of modern equipment for winter road maintenance is an urgent task today.

For full mechanization during winter road maintenance, we use a wide range of equipment. These are snow plows, snow loaders, ice scrapers, and sand throwers. Snowplows are rarely used on country roads, mainly where the ability of snowplows to throw snow a considerable distance from the roadway is limited or completely excluded. They are also used to clear snow drifts from roadsides. Snow plows are mainly used on road sections in populated areas.

The purpose of this scientific article is the analysis and comparison of existing snow removal equipment for winter maintenance of highways and city streets, and the development of an auger snow plow for maintenance of roads in the winter period, namely, the removal of snow cover from the carriageway.

Today, snow plows are manufactured by many companies around the world and are available for various types of vehicles. They are available with manual, electric, and hydraulic drives. They have different sizes and designs.