Introduction. The method of strengthening the reinforced concrete structures is chosen depending mainly on the cost and timeframe of the performed work. In each specific case, the decision is made depending on the load, type of defects, operational features, etc. Apart from the direct costs of inspection, strengthening project design, materials, lifting and transport services and the cost of strengthening works proper, there is a number of additional costs related to the technological features of the work performed. Among the new methods of strengthening, the method of external strengthening with the composite carbon materials can be particularly emphasised. Compared to the previously developed methods of strengthening with the reinforced concrete and metal, the composite systems are easily transportable and do not incur additional costs. The aim of this study is to determine the method of strengthening most rational for the compressed structures.

Materials and methods. The authors have examined three methods of strengthening the compressed reinforced concrete structures. In the frame of the research a numerical experiment has been carried out, in which a reinforced concrete column was strengthened at different strengthening coefficients from 1.1 to 2.0, i.e., from 10 to 100% of strength increase. The estimations of the cost of strengthening the column by three methods of strengthening have been carried out: jacketing using the reinforced concrete, metal and composite materials. After carrying out thirty variants of calculation, a table presenting all specifications and quantities of the materials has been drawn up. At the final stage of the research, the total cost of each method under investigation has been estimated based on the prices of the selling companies.

Results. The analysis of strengthening with the reinforced concrete revealed that at most of the strengthening coefficients the achieved structural reinforcement is minimal. Under the high loading levels strengthening with the metal is not economically expedient, as it implies the use of the large-section angles.  The composite material systems of external strengthening are very material-consuming at all load increasing coefficients. Taking into account the high cost of materials, this method is basically the least economically expedient.

Discussion and conclusion. Based on the results obtained, the efficiency of three most common methods of strengthening the reinforced concrete compressed columns was analysed. Proposals on the rational design of the strengthening systems for the eccentrically compressed reinforced concrete poles under the different eccentricities of load applied have been developed.

Introduction. A number of research held in recent years on rational design of buildings and structures built for different purposes study the rational position of the vertical members — columns or supports. However, the majority of up-to-date research and publications focus on elucidating the rational position of the supports in the context of improving the efficiency of the beams. Whereas the behaviour of the reinforced concrete slabs affected by changing the position of the supports is not covered well enough in the modern research. The present study is targeted exactly at revealing the behaviour of the reinforced concrete slab structures of a building in case of varying position of the main supports.

Materials and methods. During the present numerical experiment, a reinforced concrete slab of arbitrary geometry with the given thickness h, the concrete grade with the respective properties and the reinforcement possessing the properties according to its class, has been investigated. Additionally, it was decided to set the distance magnitudes from the centers of gravity of the upper and lower row of reinforcement to the bottom and top surface of the slab 𝑎_𝑥, 𝑎′_𝑥, 𝑎_𝑦, 𝑎′_𝑦. The number of columns n was set for the slab. It was considered that the number of columns was known, but their position could change. Moreover, among the total number of columns, there were distinguished the certain ones having the definite (constant) position, whereas the remaining supports could change their position within the slab area. Bearing in mind the above, the researchers were to solve the problem of rational position of the moveable columns.

Results. This paper presents the results of the numerical experiment on identifying the most optimal (rational) position of the reinforced concrete columns supporting a slab of the arbitrary geometry. Based on the several parameters at once, such as deflection, potential strain energy and consumption of the reinforcement products, the analysis of the rational position of the supports under the slab was made and functional dependences on changing the above mentioned parameters have been presented in the work.

Discussion and conclusion. Based on the results obtained in the numerical experiment, the analysis of the behaviour of the reinforced concrete slabs of a set thickness upon changing the position of the supports under the slab was made and the changes of the slab operational parameters were analysed and compiled into the functional dependences. 

Introduction. During design, construction and operation of buildings and structures in the coastal areas there arises a serious problem of engineering protection of coasts and hillslopes from the dangerous geological processes, which include the coastal erosion, underflooding of territories, hillslope erosion, gravitational (slope) processes, such as intensification of landslides, etc. These processes often result in significant economic damage usually related to the non-recoverable loss of valuable coastal territories, deformation of buildings and structures, damage and destruction of the objects of transport and engineering infrastructure. In this regard, the study of the advanced foreign experience in engineering protection of the coastal areas and the evaluation of the possibility of it to be implemented in Russia is a relevant scientific and engineering task.

Materials and methods. To prepare the review, the following data was used: field observation data with photographic evidences of the objects of engineering protection of seashores and hillslopes obtained by the authors during a business trip to the People's Republic of China (PRC) in October–November 2023; study and analysis of literature sources in the subject area, including the methods and technologies implemented in the Netherlands, Japan, the USA, Great Britain, Italy; summary and systematisation of the coastal protection methods for further development of their classification and evaluation of the possibility of implementing thereof in the Russian Federation.

Research results. The main principles of design, the advanced methods and technologies of coastal protection used in China have been defined. They include: construction of the multi-level protective structures, such as the multiple-row breakwaters of special shape in combination with the stepped retaining walls, the vertical walls consisting of the driven piles, anchoring and spray-concrete covering of the slopes in combination with the metal meshes; terracing in combination with the retaining reinforced concrete (horizontal and vertical) crossbeams; the sloping wave-absorbing reinforced concrete surfaces;  the meshy structures and fences combating the Aeolian processes, etc.

The main methods used in the Netherlands, Japan, the USA and Italy for comprehensive protection of the large territories have been defined. Such as: the network of dams, weirs, wave breakers, coast paving, regulation of the flows by water locks and barriers, creation of the artificial protective islands; artificial replenishment with sand; creation of the green spaces along the coast; forming the dunes — natural or artificial hills of sand or pebbles located along the coast; creation of the concrete structures, stone jetties, floating constructions and even artificial reefs.

The importance of management was emphasised, including the early warning systems for storms and tsunamis, weather and marine condition monitoring systems, as well as dissemination of the warning messages and evacuation plans among the population in the areas of potential threat.

Discussion and conclusion. Based on the results of the review, the main conclusions were formulated. The recommendations were given on the possible ways of improving the coastal protection of the Caucasian Black Sea Coast and other coastal areas of the Russian Federation based on the advanced foreign experience.

Introduction. Every year, the scale of construction of buildings and structures in the large cities increases, thus leading to generation and accumulation of a considerable amount of a wide range of different sort of construction waste in various aggregate states. At the same time, each type of waste is characterised by a certain set of properties with the parameters that determine the possibility of its future reuse, therefore there arise the urgent problems to be solved by society not only concerning the reduction of the environmental pollution, but also disposal, and at best recycling the waste.

The data on the specifications of the construction waste properties, which determine its behaviour in the environment, is extremely important for solving these problems.

In the works of the native and foreign scientists on solving the construction waste management problems, the features of its behaviour in the environment were hardly ever studied, nor was the relationship between the distinctive features of its components and the environment characteristics enough revealed, and the boundary conditions referring to this relationship were not fully taken into account.

That is why the authors present the results of the research on the classification of the distinctive features of the construction waste by grouping the parameters of their properties based on the theory of disperse systems stabilisation. Besides, the parameters of the construction waste properties have been investigated both for the dispersed phase and the dispersion medium, whereas the physical entity of the processes and phenomena observed in the construction waste has been chosen as the main classification criteria.

Thus, the research aims to analyse and systematise the construction waste properties, based on the theory of disperse systems stabilisation in terms of extending the scope of the waste reuse in various sectors of economy.

Materials and Methods. The object of the study is the construction waste generated in a result of the technological processes at the enterprises of the construction industry. Construction waste and its properties are investigated from perspective of the theory of disperse systems stabilisation. The classification of the parameters of the construction waste properties is carried out on the basis of the physical processes and phenomena that are characteristic for a particular type of waste. The construction waste properties and the parameters describing them are presented both for the dispersed phase and the dispersion medium.

Results. As a result of the conducted research, the generalised parameters of the construction waste properties have been systematised based on the theory of disperse systems stabilisation in terms of extending the scope of the waste reuse in the business activities that leads to reducing the environmental pollution.

Discussion and Conclusions. The proposed classification of the construction waste parameters will make it possible: – to change the behaviour of the waste in the environment aiming to reduce the environmental pollution and to extract the waste components from the environment for their further reuse in the business activity after pre-treatment resulting in the necessary property parameters;

– to decrease waste stability, i.e. its ability to resist the external impacts, and thereby also ensure the reduction of the environmental pollution at the final stage of the waste life cycle.

Introduction. Construction of the green healthcare buildings is a rather new and priority direction of construction in China. One of the key components of efficient implementation of the projects of green healthcare buildings is the cost management of a construction investment project. The projects of green buildings envisage the advanced technical content of a facility, a wide project scope and large number of participants. Therefore, the cost management requirements have to be more demanding, however, the traditional fragmented management fails to meet the requirements fostering the development of the green healthcare buildings. The present research investigates the issues of cost management of the green healthcare construction projects, analyses the necessity, feasibility, development trends and practical cost management problems thereof. The research strives to develop the cost management assessment indicators for all life cycle stages of the projects of green healthcare buildings.

Materials and Methods. The research was conducted using such methods as the literature review and the expert interview methods. The expert interview method allows using the experience of experts from the related fields to assist in decisionmaking. Therefore, a questionnaire was developed as a part of the research.

Results. Upon in-depth study of the various factors affecting the cost management of the green healthcare construction projects, the strategies and response measures have been developed based on the advantages and cost management features. By summarizing the cost management assessment indicators referring to implementation of the green healthcare construction projects and by combining the opinions of the experts and scientists from the related fields, the cost management assessment system for a project of green healthcare building has been created. The created assessment indicators make it possible to implement better control over the costs assigned to the green healthcare construction projects, elevate the level of project cost management, enhance the integrated benefits of the project and ensure the cost management and cost control for the similar projects.

Discussion and Conclusion. The results of the research provide a theoretical basis for creating a cost management assessment system for the green healthcare construction projects aimed to solve the problems of cost management of the green healthcare buildings. The practical significance consists in providing a real practical approach to improving the cost management of the projects of green healthcare buildings.

Introduction. High concentration of PM2.5 has the adverse effect on people's health. According to the evaluations made by the researchers, the impact of the particulate matter from the construction dust emissions resulted in 18% of deaths from respiratory diseases. Due to the growth of construction production volume and consequent increase of dust emission volumes, there arises the need to expand the scope of using the end-to-end technologies, namely the artificial intelligence technologies, for predicting the fine-dispersed dust particles PM2.5 concentration in dust emissions at the construction site.

Materials and methods. To achieve this goal, the measurements of PM2.5 concentration at the construction site were carried out using the Handheld 3016 IAQ particle counter in the period from July 1 to July 6, 2023 taking into account the meteorological characteristics of the territory, which then became the input data for modelling the forecast of dust pollution concentration using such algorithms as ARIMA, EMA, XGBoost, etc., and the ensemble models that included the above machine learning algorithms. The efficiency of using these technologies for predicting was determined by comparing the results of the forecast and the field measurements data.

Results. A correlation analysis was performed using the Modeltime program, which determined the relationship between PM2.5 concentration and meteorological variables. Autocorrelation was performed using Pearson correlation. At the first stage, four one-dimensional models based on the artificial intelligence were evaluated to determine the accuracy of mean concentration forecast. The next step was to evaluate the capacity of predicting the mean PM2.5 concentration using the multidimensional models that took into account the relationships between the independent and dependent variables. At the final stage of the research, three most efficient predictive models were included to test the ensemble model.

Discussion and conclusion. The reliable predictive models can be the useful tools for understanding the concentration impact factors. In the present research, seven machine learning algorithms were used to predict the concentration of PM2.5. The research, as a whole, presents the evidences of the integrated modeling method efficiency for predicting the air pollution. 

Introduction. The paper investigates the methodology for determining the rheological parameters of materials based on the nonlinear Maxwell-Gurevich rheological model using the stress relaxation curves. The review of the main directions of the metaheuristic approaches (local search, evolutionary algorithms) to solving the combinatorial optimization problems is presented. The metaheuristic algorithms for solving some important combinatorial optimization problems with the special emphasis on building decision trees are described. The comparative analysis of the algorithms for solving the regression problem in CatBoost Regressor is carried out. The aim of the work is to determine the rheological properties of polymers using machine learning techniques.

Materials and Methods. The objects of the study are the generated data sets obtained on the basis of the theoretical stress relaxation curves. The source data tables for model training across all samples are presented, and the statistical analysis of the source data sets characteristics is carried out. The total number of numerical experiments across all samples amounted to 346020 variations. To develop the models, the CatBoost artificial intelligence techniques were used; the regularization techniques (Weight Decay, Decoupled Weight Decay Regulation, Augmentation) were used to increase the model accuracy; and Z–Score technique was used for data normalization.

Results. As a result of the research, the intelligent models for determining the rheological parameters of polymers (initial relaxation viscosity, velocity modulus) have been developed based on the generated data sets on the example of the epoxy binder EDT-10. Based on the testing results of the models with the best parameters, the quality assessments were carried out: for the parameter 𝜂^∗₀ the range of values MAPE 0.46 — 2.72, MSE 0.15 — 1.09, RMSE 0.19 —  0.44, MAPE 0.46 — 1.27; for the parameter 𝑚^∗ — MAPE 0.07 — 0.32, MSE 0.01 —  0.13, RMSE 0.10 — 0.41, MAPE 0.58 — 2.72. The resulting metric values are permissible. The training graphs demonstrate the stability of the process.

Discussion and Conclusion. The developed intelligent models are scalable and cross-platform, have practical applied significance that ensures their implementation in a wide range of the scientific and engineering apps. 

Federation Government Resolution on Adoption of the Concept of the Federal Target Programme "Development of the Domestic and Inbound Tourism in the Russian Federation (2019-2025)" foresees the comprehensive development of the tourist clusters in the priority types of tourism1. Within the tourist industry, the ethnic tourism is one of the priority directions, which has the great potential, but is still in the stage of infancy. Currently, there are 49 ethnographic centres in 36 regions of our country. In recent years, the trend for creating the ethnography-oriented recreation centres in the south of Russia becomes evident. In the south of Russia the following destinations are referred to such centres: the ethnographic centre "My Russia" in Greater Sochi on the territory of Rosa Khutor, the “Ataman” exhibition complex in the village of Taman in the Krasnodar Region, the ethno village of the Nekrasov Cossacks and Molokan Spiritual Christians in the Stavropol Region, Novokumsky settlement, however, their number is not enough for the territory of the south of Russia. The acquaintance with the experience of building and designing the ethnographic facilities has led to the conclusion, that nowadays the creation of a new type of the ethnographic centres combining the education and recreation functions with resting in the natural environment is highly relevant. However, the normative and methodological documents regulating their creation are missing.

Materials and methods. The research included: the analysis of development of the various types of the ethnographic facilities using the analytical and graphical analytic methods, field research and photo-fixation, as well as the comparative analysis of the functional zoning and layout, spatial arrangement and composition of the ethnographic museums and the ethnographic parks "in the open air". The article investigates the foreign and domestic examples of the facilities.

Results. Based on the study of the ethnographic facilities, the main scientifically based urban planning principles for creation thereof have been distinguished, their features and territorial planning distinctions within the structure of the settlements have been found. The research results are being piloted within the conceptual project of layout and development of the tourist ethnographic centre in the city of Semikarakorsk, Rostov region. The proposed project aims at creating the tourist ethnic environment within the structure of the planned urban settlements of the south of Russia for preserving the Don Cossacks’ traditions and boosting the development of the ethnic tourism in the south of Russia.

Discussion and Conclusion. The layout and functional zoning of the ethnographic centres depend not only on the urban planning situation, location of their territory within the structure of the urban entities, but also on the identity of the culture represented on their territory. The results of the study enable the geographical expansion of the ethnographic centres across the south of Russia, increase the range of the recreation and education services provided within the urban environment through their enlargement and transformation, bring a person closer to the natural environment and different peoples’ national environment. This will enable each ethnographic centre to demonstrate its distinctive features ensuring its individual character.

Introduction. The present article raises an issue important for breadboarding — the future of this field of activity. Breadboarding is a developing technology, which has become a sphere of occupation for many people, whose work results are highly appreciated in the fields of science and construction. 3D modeling is also becoming popular in the similar fields, having its own digital (innovative) advantages. The detailed analysis, allows us to find the pros and cons of both technologies.   

Materials and Methods. The methodological framework of the research includes the conventional scientific methods, as well as the emerging interdisciplinary approaches characteristic for the architecture and construction. The material studied in the present article refers to the evolution of the technological concepts of architectural prototyping the facilities of capital construction and reconstruction by the example of 3D modeling and breadboarding.  

Results. It has been found that form making by means of breadboarding and 3D modeling is widely used at different stages of the advanced construction, innovative reconstruction and up to date restoration. 

Discussion and Conclusion. The study of breadboarding and 3D modeling reveals that these technological concepts are getting popular in the fields of construction and architecture.