The article discusses the features of modeling composite reinforced concrete beams from various (B25 and B65) concrete strength classes. The basic principles of the theory of composite rods were applied in the modeling process. The section of the reinforced concrete beam was divided by boundary layers with a reduced shear coefficient. The stresses and the nature of the distribution of deformations over the height of the beam section were evaluated before and after the introduction of a different number of boundary layers. During the extended analysis, options for introducing vertically arranged boundary layers along the length of the beam were considered. Based on the results obtained, it was possible to evaluate the specifics of the operation of bent structures with a different number of boundary layers.

Keywords: contact zone, contact characteristic, shear modulus, shear calculation, composite structure, reinforced concrete beam made of high-strength concrete

Currently, bitumen-polymer roofing materials are used in the construction of various types of buildings and structures, which have sufficient strength characteristics, wear resistance, water resistance and are convenient for installation. The mechanical properties of bitumen-polymer materials are significantly affected by the operating temperature. Of scientific interest is the analysis of the possibility of restoring the integrity of bitumen-polymer roofing materials at elevated temperatures, damaged as a result of mechanical stress at subzero temperatures. The article presents the results of testing the flexibility of samples of roofing bitumen-polymer materials at subzero temperatures. The samples that were damaged during the test were subjected to subsequent heating in a temperature chamber in order to identify the possibility of restoring the integrity of the material and the temperature at which the restoration would occur. The analysis of the test results showed the possibility of restoring the integrity of the material and the direct dependence of the quality of restoration of integrity on the heating temperature of the material.

Keywords: restoration of integrity, bitumen-polymer materials, roofing materials, flexibility, influence of temperature

The article is devoted to the development of modular construction in Russia and related problems. Given the ongoing shortage of living space and the need to modernize the housing stock, modular construction is a promising solution for the rapid construction of affordable housing. Despite the advantages such as faster implementation times, high flexibility and adaptability to various needs, and the ability to quickly dismantle and expand buildings, the technology faces serious challenges in Russia. The lack of a unified regulatory framework and certification brings additional difficulties with financing and lack of infrastructure, which significantly limits the mass use of modular structures. These factors slow down the process of integrating modular construction into domestic construction practice. At the same time, international experience and successful examples of the implementation of such projects, such as the Habitat 67 residential complex in Canada and the high-rise building "Naikagin Capsule Tower" in Japan, demonstrate the possibilities of modular construction in various sectors. Russia continues to actively work on the adaptation of modular technologies, which opens up prospects for solving housing problems and the rapid construction of social facilities. In the country modular construction can play an important role in solving housing problems, especially in regions where traditional construction methods are economically impractical. Despite the existing problems, the implementation of this technology continues to evolve, which opens up prospects for future growth and improvement of the construction industry in Russia.

Keywords: modular construction, energy efficiency, prefabricated buildings, regulatory and technical documentation, block modules, modular systems, frame buildings, modular buildings, modular construction technology

The article deals with the principles of creating software used as part of sensing systems for restoring the visibility of the gas smoke protection service link in a smoke-filled environment during rescue operations. The architectural part of the device and the description of algorithms of the device operation are described. Attention is paid to the methods of forming a digital model of obstacle heights and visualization of the spatial situation. Approaches to filtering of erroneous sensor values and selection of significant contours of objects, processing of data from ultrasonic grating, infrared sensors, as well as temperature and humidity sensors are given. The role of the device in providing accurate navigation, reducing the time to search for the fire center and improving the overall safety of the gas smoke protection service unit when working in a smoky environment is emphasized.

Keywords: smoke protection service, smoke-filled environment, sensing device, algorithms, software, firefighting, reconnaissance, modeling, navigation, sensor data

The article considers a variant of constructing a model of a solar battery orientation drive based on a DC motor and PID control. Orientation in space is performed along two axes: azimuth and zenith. The model is used for optimal adjustment of PID controller parameters when processing the required orientation angles under gusty wind conditions. The following are used as the main adjustment criteria: small overshoot when processing the angle, aperiodic (non-oscillatory) nature of transient processes, minimum dynamic error in compensating for wind effects when processing the angle, minimum settling time when processing the effect. The controller was optimized using the coordinate descent method. A variant of controller adjustment for the optimal mode is given with process graphs confirming its practical optimality. The constructed drive model can be used to implement a digital twin of the solar battery panel orientation drive monitoring and control system.

Keywords: mathematical model of the drive, PID controller, solar panel, gusty wind effects, azimuth and zenith orientation, optimization by complex criterion

Toughening of requirements to buildings’ power efficiency enables development and implementation of modern lightweight concretes on efficient porous aggregates into building industry. The key demands to both lightweight heat-insulating and to fine concretes are ensuring low density index and thus low thermal conduction with high durability provided. There has been developed a lightweight heat-insulating fine concrete mix with the use of three fractions of granulated foam glass. To conduct the research there has been used a central composite design, which helped determine optimal consumption of separate fractions of granulated foam glass, and acquire a lightweight heat-insulating fine concrete with the lowest density. On the basis of obtained research results there has been carried out a calculation of thermal conduction ratio with the use of empirical formulae. The research results have been analyzed, and their descriptive statistics have been presented as diagrams and graphs. On the basis of the analysis of the research results there have been obtained regression equations and established influence degree of separate fractions of granulated foam glass on the density and thermal conduction ratio. There has been carried out an optimization of the material mix and the correlation between fine aggregate fractions calculated to provide the lowest average density.

Keywords: fine concrete, granulated foam-glass, thermal conduction ratio, average density, durability, experiment design, regression, mix optimization

The article analyzes modern approaches to the use of innovative materials to create an inclusive environment in residential buildings. The paper examines the main problems associated with the obsolescence of building materials, and offers promising solutions based on the use of adaptive and environmentally friendly technologies that enhance accessibility and comfort.

Keywords: inclusive environment, the problem of outdated materials, innovative materials, innovations, trends and prospects, bioplastics, carbon concrete, OLED panels, adaptive structures, accessibility, comfortable environment, design

This article presents a conceptual model of the reconstructive solution of an industrial enterprise in the structure of a large industrial unit in the engineering industry. Based on the multifactorial analysis of the enterprise, a model was proposed that ensures the compliance of the reconstructed production environment with the updated requirements for industrial facilities located in the structure of dense urban buildings.

Keywords: industrial buildings, reconstruction of industrial buildings, architecture of industrial buildings, aesthetics of industrial buildings, conceptual models of industrial buildings

The article describes the mathematical foundations of time-frequency analysis of signals using the algorithms Empirical Mode Decomposition (EMD), Intrinsic Time-Scale Decomposition (ITD) and Variational Mode Decomposition (VMD). Synthetic and real signals distorted by additive white Gaussian noise with different signal-to-noise ratio are considered. A comprehensive comparison of the EMD, ITD and VMD algorithms has been performed. The possibility of using these algorithms in the tasks of signal denoising and spectral analysis is investigated. The estimation of algorithm execution time and calculation stability is performed.

Keywords: time-frequency analysis, denoising, decomposition, mode, Hilbert-Huang transformation, Empirical Mode Decomposition, Intrinsic Time-Scale Decomposition, Variational Mode Decomposition

The article shows calculation on the arrangement of the embankment and the design of reinforced concrete casings on metal staves for stairs. The dam boundaries are located on the territory of a residential complex with a large difference in height. The ground base is prosaic. Calculation of transfer of the soil from II type of drilling to I type by tamping method, which will ensure the strength and reliability of the body of the fill. Constructive actions to ensure resilience are described. The metal piles with forced connecting link and reinforced concrete coaxes in the form of a beam system have been designed.

Keywords: a mound, drilling ground, improvement, dense urban development, sediment, density of the ground, collapse prism, sliding radius, the method of ramming, sling

This study investigates the integration of piezoelectric elements with marine buoys for the purpose of utilising wave energy in autonomous marine devices. The buoy system was subjected to controlled wave conditions during testing, resulting in a peak voltage of 5.6 V and a maximum power of 40 microW. The findings indicate the viability of the system in powering low-power marine equipment. The integration of piezoelectric elements into marine buoy systems offers a cost-effective hybrid solution, making it a promising power source for powering buoys and sensors in remote offshore environments.

Keywords: wave energy conversion, sea waves, piezoelectric elements, wave height, wavelength

The paper proposes and specifies the engineering mathematical model of the drive using a block of ferrofluid couplings and, within the framework of preliminary design, studies its dynamic properties, in the course of which transient characteristics are obtained, allowing to assess the qualitative performance of such a drive and to outline measures for their improvement.

Keywords: uninterruptible power supply system, automatic regulation, relay voltage regulator, relay system modeling.

The purpose of this work is to study the thermal stress of the furnace of a fire-tube boiler and its effect on the design of the boiler. To study the effect of thermal stress and furnace proportions on the ratio of heating surface areas, the calculated resistance was tested. Calculations of heat-tube boilers of sectional hot-water boilers with different proportions of the furnace at different thermal loads of the same furnace volume are performed. The calculation of each heating surface is carried out by the method of successive approximations, based in this case on the chord method. In the calculation process, the flue gas temperature at the outlet of the heating surface was first set, and then refined by successive approximations. To reduce the overall balance of the boiler, another global approximation is made when the temperature determined at the outlet of the last heating surface is set at the beginning of the calculation – in the heat balance, where it affects the loss with outgoing gases and the efficiency of the boiler. It is determined that the optimal.

Keywords: energy efficiency, fire-tube boiler, heat supply, thermal voltage, resource conservation

A combined theoretical and practical study of the burner device parameters has been performed. The flow characteristic of the fuel supply system has been determined. Aerodynamic studies of the burner device characteristics have been conducted, axial velocity fields have been constructed, and critical parameters of the air supply unit design have been identified. The temperatures of in-chamber processes have been experimentally determined. A mathematical model of chemical reactions of the torch has been developed, and the dependence of diesel fuel toxicity on the excess air coefficient has been constructed. The effect of water vapor on the burner device operation has been determined.

Keywords: burner device, axial velocity field, intra-chamber processes, thermochemical parameters, mathematical modeling, toxicity

The paper considers the choice of the optimal technology for the construction of tongue-and-groove fencing based on the hierarchy analysis method. Decision-making in construction practice requires consideration of many factors, including internal (cost, reliability, speed of work) and external local conditions (risk of interruptions in the supply of materials, the influence of weather conditions, work in cramped conditions). The hierarchy analysis method makes it possible to formalize the decision-making process by structuring the task in the form of a hierarchy and comparing alternatives in pairs. In the course of the study, a comparative analysis of the technologies of hammering, vibration immersion and static indentation of sheet piles was carried out. Priority vectors for each criterion were calculated, and the consistency of the matrices was checked. The final choice of technology is justified based on the integration of internal and external factors. The results obtained allow us to recommend the optimal technology that takes into account the technical and organizational features of the construction process.

Keywords: tongue-and-groove fencing, technology selection, hierarchy analysis method , selection criteria, construction technologies, pairwise comparison, priority vectors