The reuse of ash and slag waste from coal combustion is of great economic and environmental importance. The most material-intensive area of their reuse is the stabilization of ash and slag mixtures with Portland cement for the construction of layers of highways. A technical understanding of the processes of structure formation in stabilized ash and slag mixtures makes it possible to regulate the final properties and quality of the layers of road clothing and the roadbed. Strengthening of ash and slag mixtures with Portland cement makes it possible to increase the physical and mechanical properties of ash and slag mixtures: strength, frost resistance, density, etc.

Keywords: ash and slag mixtures, stabilized ash and slag mixtures, structure formation of stabilized ash and slag mixtures, sportland cement, microstructure of the ash and slag mixture

The loading history, including duration, stress level, number of cycles and environmental influences, also affects concrete performance by increasing strength while reducing deformability. Under long-term service, concrete can exhibit elastic behaviour until stresses in the order of 70-80% of the expected compressive strength are reached. The plastic and viscous properties of concrete play an important role under dynamic loading, determining its dynamic hardening capacity. Thus, long-term operation significantly alters the dissipative properties of concrete and affects its response under accidental dynamic effects. The aim of this study was to assess the extent to which the deformed state of the frame as a result of the erection sequence, creep and shrinkage strain accumulation influences the collapse resistance in an emergency situation.The process of deformation of reinforced concrete frame of a multi-storey building in an emergency design situation was modelled, taking into account the stage of construction and different age of concrete at the moment of load application. The computational analysis was performed in quasi-static formulation in Scad Office 21.1.9.9 using the ‘Assembly’ module.According to the results of the study, deformations and forces in the elements of the load-bearing system after the initial local collapse in it have been obtained and analysed. It is shown that when taking into account the sequence of building erection, accumulation of creep and shrinkage deformations, the building resistance to progressive collapse decreases.

Keywords: monolithic reinforced concrete frame, progressive collapse, creep, shrinkage, modulus of elasticity, modulus of deformation, static-dynamic loading

The installation of foundations of production facilities on sites subject to karst formation and suffusion processes in conditions of weak soils is a serious problem in the design and construction of large distribution centers. In such a situation, it is necessary to calculate the load-bearing elements of the building for the effect of the lack of reaction of the base under the sole of the foundations on a site with a diameter of 3.0 m, located in the most unfavorable places from the point of view of structural work. Such unfavorable locations of a karst sinkhole can be determined by digitally constructing "influence functions" and obtaining "envelope" diagrams of pressure on the base, foundation sediment, and structural reinforcement. If the maximum allowable precipitation of the foundations obtained by calculation is exceeded, it is possible to strengthen the soils by layer-by-layer recycling, which will allow reaching the normative indicators.

Keywords: karst formation, suffusion, sinkhole, calculated combination of loads, special combination of loads, reinforcement, foundation sedimentation, ground pressure

The article analyzes the issues related to the implementation of construction control at the facilities of existing enterprises during their reconstruction. The authors conduct the research based on the use of methods of scientific analysis, synthesis, generalization and systematization. The work uses domestic and foreign scientific sources, examines the experience of advanced construction control technologies and their implementation practices. Special attention is paid to the use of digital technologies, such as monitoring systems, automated controls and modern software solutions. The theoretical basis of the research was scientific works on construction control, regulatory legal acts and standards, as well as publications on modern methods and approaches to the reconstruction of enterprises. The empirical part is based on the analysis of real data on construction control at enterprises, including identifying problems and evaluating the effectiveness of applied solutions. As a result of the research, an optimized structure of construction control has been developed, innovative technologies and recommendations for their implementation have been proposed. The effectiveness of the new model has been evaluated, showing its advantage over existing approaches. The theoretical significance lies in an in-depth understanding of modern methods for performing construction control, including the use of digital technologies. The practical significance of this work lies in the potential of applying the proposed solutions to improve the quality of enterprise reconstruction, which in turn contributes to the sustainable development of industry and the reduction of operational risks.

Keywords: construction control, operating company, reconstruction, entrance control, operational control, acceptance control

The paper considers the problem of the stress state of a rock array with continuous inhomogeneity. This type of inhomogeneity can be observed in rock arrays with cavities created by explosion. In this case, the dependence was chosen when the main mechanical characteristics depend only on one coordinate - the radius. It was also taken into account that the chosen dependence gives an opportunity to obtain relatively simple methods of solving the problems. The chosen calculation scheme of the problem allows to reduce it to the solution of one-dimensional task. For the case of the centrally symmetric problem we consider the solving equation, which is an ordinary inhomogeneous differential equation of the second order with variable coefficients. Using the substitution of variables, we can proceed to the solution of the hypergeometric equation. Solutions of hypergeometric equations are given in the form of hypergeometric series, which are known to converge. Using inverse substitutions, the stresses are found. The stress state of the rock array at different degrees of its heterogeneity is determined. The results are presented in the form of graphs. Comparison with similar solutions for homogeneous arrays is carried out. The presented results allow us to conclude that when solving problems on the stress state of rock arrays with cavities, it is necessary to take into account the heterogeneity of the arrays obtained in the process of creating such cavities with the help of explosion.

Keywords: heterogeneity of the medium, rock array, spherical cavity, stress state

In the process of developing a plot of the junction field, the theoretical calculation of the load capacity and the permissible load on the piles is carried out, based on which the number of piles and their arrangement are decided. The results of theoretical calculations are in some cases underestimated when compared with actual values, and the application of theoretical calculation may lead to an increase in construction costs. The article examines the change of pile size and position in a swave field after the actual results of the field tests are obtained. The technical-economic comparison was carried out and the conclusion of the effectiveness of the adopted solution for the three designed houses was drawn.

Keywords: pile, load-bearing capacity, the maximum weight load, pile field, techno-economic comparison

The article contains the results of the inspection of power transmission line structures within the framework of the preparation of design documentation for the reconstruction of cable racks and power transmission line supports due to the increase in the diameter of cables and, as a consequence, the increase in the load on the racks located in the Chaunsky District of the Chukotka Autonomous Okrug. The article presents a geodetic survey of load-bearing structures (determination of deflections and displacements of structures), lists of defects and damages, verification calculations of structures, and measures to strengthen structures.

Keywords: bearing capacity, inspection of structures, overhead power lines, wooden structures, supports, overpasses

The cargo turnover of modern distribution centers of network operators reaches hundreds of thousands of tons per year. The technological load on the floors in the warehouse part of the building is 8-10 t/m2 (80-100 kPa), on the floors – up to 2.4 t/m2 (24 kPa). These loads transfer significant pressure through the foundations of the frame to the ground, which, with large sole sizes and mutual influence, increases the lower boundary of the compressible thickness and, as a result, the draft of structures. In the presence of weak soils at the base, precipitation reaches exorbitant values. The situation is aggravated by the high groundwater level, which also increases the sedimentation of foundations. The article presents and analyzes options for solving the problem by strengthening the base by compacting the top layer and cementing it to different depths depending on the pressure and construction of the foundation.

Keywords: reinforcement of the base, recycling, permissible calculated precipitation, calculated soil resistance

The application of a mechanical-empirical method of designing road pavement for predicting track formation on the surface of road structures is discussed in the article . The occurrence of ruts is one of the most common types of defects in road surfaces, significantly reducing safety and comfort of movement. MEPDG calculation models were used in this work for assessing the stability of a road structure to the accumulation of plastic deformations. Models takes into account factors such as the intensity and axial load of transport, climatic conditions, and the physic and mechanical properties of coating materials. An example of predicting the depth of a track using the considered method is given.

Keywords: rutting, mechanical and empirical method, road pavement, forecasting, MEPDG, traffic loads, climatic conditions

A significant number of long-span public buildings with spatial steel structures are designed, erected and exploited in our country. One of the main areas of their application are unique sports objects. In the article experience of dye penetrant inspection of the Gorki Gorod Mall's long-span steel dome's welded joints is analyzed. The shopping and entertainment center was built in Sochi for the 2014 Olympic Games. Methodology, advantages and disadvantages of dye penetrant inspection are given. Typical defects of welded joints in spatial metal structures identified by this method are described. The data obtained from the experience of use of such structures allows to actualize and expand the developing normative documents.

Keywords: defect, dome, dye penetrant inspection, grid shell, inspection, long-span structure, non-destructive testing, spatial rod structure, steel structure, welded joint

Road construction plays an important role in the infrastructural development of any country. Road infrastructure is a network of roads and motorways that move goods and passengers between and within cities and regions. A well-developed road network contributes to economic growth by providing easy access to markets, reducing transport costs and facilitating more efficient logistics. Roads play an important role in providing accessibility to remote and sparsely populated regions, which contributes to the social and economic development of these areas. Modern motorways provide safer and more comfortable travel for drivers and passengers, and reduce journey times. Roads serve as an important part of the transport infrastructure for the movement of goods. They provide access to ports, railway stations and other transport hubs. Well-developed motorways contribute to the development of tourism as they make tourist destinations and attractions accessible. The article provides a statistical analysis of the construction of federal and regional highways in the period 2021-2023 for eight districts of the Russian Federation. Diagrams of the length of constructed motorways in each district are given, and the main parameters of descriptive statistics are calculated.

Keywords: roads, construction, road infrastructure, motorways, motorways, non motorways, statistical analysis

When designing flat reinforced concrete slabs, the most complex and responsible structural unit is the area where the slab is supported by the columns and walls. This is due to the action of large concentrated efforts and the greatest density of reinforcement. In view of this, the issue of choosing calculation methods that most accurately estimate the punching capacity for suchstructural units is relevant. With an increase in the ratio of the dimensions of the sides of the pushing structure, the force ceases to be distributed uniformly along the pushing contour and a concentration of forces occurs near the short side. This article is devoted to the evaluation of the results of finite element modeling and calculations of the bearing capacity for pushing in the area of ​​the end of the pier, analysis of the influence of the floor thickness, the dimensions of the pier and the class of concrete on the concentration of pushing forces in the floor near the end of the pier.

Keywords: punching shear resistance, flat reinforced concrete slab, static load

The article discusses the use of liquid chlorides of natural genesis to combat winter slipperiness. The aggressive effect of liquid chlorides on snow removal equipment, road structural elements and the environment as a whole is also studied. Methods for assessing the effect of liquid chlorides on metal and cement concrete are developed. The article presents conclusions and recommendations on the use of liquid natural chlorides to combat winter slipperiness on roads.

Keywords: liquid chloride, formation water, brine, corrosion rate, cement concrete pavement, winter slipperiness

Today in the modern world many architectural solutions are aimed at improving the quality of the environment, increasing energy efficiency by minimising the consumption of artificial light. One of the solutions to these problems is the use of natural light, thanks to which it is possible to reduce the impact of artificial lighting, reduce energy consumption. As it is known in most cases daylight enters the premises through translucent constructions, it is the correct design of windows that makes it possible to increase the flow of sunlight. Depending on the window parameters it is possible to control, distribute the natural light coming into the room. The article considers the influence of the ratio of windows to walls as one of the design options for optimising natural light. The research will be carried out with application of modelling in the software complex for calculation of distribution of daylight.

Keywords: natural light, natural light factor, translucent structures, optimisation, area, modelling, walls, working surface, illuminance, vertical expansion, horizontal expansion, recommendations, model, energy efficiency

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

The work deals with the study of the reliability of welded joints of pipeline systems, provided that there are various types of defects in the welds: external undercuts, internal undercuts, pores. Finite element modeling of welded joints was performed and the intensity of operating stresses was calculated using the Ansys application software package. Stress concentration coefficients are calculated and the probability of trouble-free operation of welded joints in the presence of the considered defects is estimated. The data obtained can be used in the design and optimization of pipeline system elements.

Keywords: modeling, reliability indicators, welded joint of piping systems

The article discusses the issues associated with the preparation of hot water in individual apartment heating systems that use a secondary plate heat exchanger of the boiler. The drawbacks of this approach are highlighted, including delays in hot water supply, the need to drain water from the pipeline, the inability to regulate temperature and flow rate, as well as the lack of recirculation capabilities. As an alternative, a system with a storage tank and a plate heat exchanger is proposed, which ensures stable water temperature, adjustable flow rate, resource savings, and the possibility of recirculation. Based on experimental studies, the heat transfer coefficient for heat exchangers with profiled and flat plates has been determined. Calculations of the required heat exchanger area are provided, depending on the type of plates, the volume of the storage tank, and its charging time, which allows for the optimization of hot water supply system design.

Keywords: plate heat exchanger, storage tank, heat transfer coefficient

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 introduces a methodology for verifying BIM models of capital construction facilities. This approach focuses on dynamic assessment of intersection collision weights, combining geometric analysis, statistical methods, and adaptive metric weighting. Key metrics considered include granularity, geometry errors, tessellation complexity, and fill factor. The proposed methodology utilizes Python implementation with IfcOpenShell, leveraging a multithreaded architecture to significantly reduce data processing time. Testing on 20 multidisciplinary models highlights critical problematic elements such as walls, beams, and air ducts. The results demonstrate that adaptive weight distribution effectively identifies and prioritizes potential errors, improving the accuracy and reliability of BIM models. The study's findings are crucial for enhancing design and construction processes. By accurately assessing and mitigating errors, the methodology reduces project delays, cost overruns, and safety risks. It also promotes better coordination among project stakeholders, streamlining workflows and improving project outcomes. In conclusion, the proposed methodology is a valuable tool for verifying BIM models, ensuring the integrity and quality of capital construction projects. Its application can lead to more efficient, cost-effective, and reliable construction processes, benefiting both developers and end-users.

Keywords: TIM, collisions, verification, dynamic weights, adaptive metrics, algorithms, IfcOpenShell, python, standard deviation

When designing engineering protection, it is necessary to use modern and progressive technologies. The technical decisions made must comply with the fundamentals of design - economic and operational efficiency. This article discusses the methods and principles of operation necessary for hazard assessment and the development of effective measures to prevent and reduce risks in the design, selection of optimal solutions and recommendations for the development of engineering protection projects. A section of a public highway of local significance in the Krasnodar Territory was selected during the survey. The materials of engineering and geological studies of the slope were used as initial data, which included reconnaissance route observations, engineering and geological workings with soil sampling, and determination of the physico-mechanical characteristics of the soils.

Keywords: engineering protection, surveys, design, stability, reconstruction, soil, landslide slope

The presented program for operation/monitoring of the mill foundation includes monitoring the development of crack width by installing beacons, monitoring the foundation vibration by means of sensors installed in the equipment structure and geodetic monitoring of foundation settlement by means of an electronic tacheometer and a level. Monitoring was performed due to an increase in the vibration level of the equipment installed on the foundation and the detection of foundation defects in the form of cracks and concrete chips.

Keywords: monitoring, bearing capacity, foundation, dynamic load, concrete, reinforcement

The article proposes to strengthen the upper chord of the triangular spacer system with fiberglass. The material used for strengthening shows high efficiency in increasing the strength of the wooden element for the 1st group of limit states. The material proposed for strengthening does not lead to a change in the original decorative expressiveness of wooden structures, and maintains the service life.

Keywords: spacer structure, upper chord, glued laminated board element, modulus of elasticity, volumetric weight, geometric characteristics, bending moment, longitudinal compressive force, structural reinforcement, composite material

Numerical studies of the temperature and humidity properties of three types of enclosing exterior walls have been performed using gas-silicate autoclave hardening blocks as the base, and a comparative analysis of the results of the study with the results of research by other authors has been carried out. The design features affecting the condensation of moisture in multilayer walls are revealed. It has been found that multilayer walls have a number of disadvantages that affect their performance and durability, in particular, the presence of materials with different vapor permeability and moisture absorption, which leads to the accumulation of moisture inside the wall. The prospects of using single-layer structures and the importance of choosing the right material for the finishing layer are shown. An example of the use of a finishing material based on acrylic and marble chips is given, and the need for further research of this material is shown.

Keywords: gas silicate block, condensation zone, plaster facade, finishing material, acrylic, marble chips

In the practice of hydraulic engineering construction, especially in mountainous and foothill areas, quite often there are conditions under which it is economically advantageous to build a dam reservoir from heterogeneous local materials with different filtration characteristics. As a rule, in such areas near the site of the future dam there is not enough homogeneous construction soil that meets all the requirements. However, it is possible to find soils that differ in water permeability, but in sufficient quantity for the construction of the body of this dam.

Keywords: reservoir, dam, filtration, soil, section, pool, anti-seepage core, flow, slope

The effectiveness of advanced pavement defect detection algorithms is considered depending on the data collection devices used, such as cameras, GPR, LiDAR and IMU sensors installed in smartphones. Rational use of these hardware and software tools will allow utilities to identify and eliminate road surface defects in a timely manner, thereby improving road safety.

Keywords: transportation sector, pavement defects, mobile road laboratories, neural network algorithms, computer vision