Over time reinforced concrete construction tend to lose their strength properties. An important factor in maintaining the integrity of reinforced concrete structures is the compliance of the parameters of the erected structure with its design values and operating conditions. Otherwise, the likelihood of defects such as the formation of cracks in the protective layer and corrosion of reinforcement increases. There are methods for restoring reinforced concrete structures that can return the strength characteristics to the design level or even exceed it.

Keywords: restoration of the protective layer, repair, inhibitor, adhesion, corrosion, penetrating waterproofing, chemical anchor, foundation, shotcreting

The problems of competitiveness of construction organizations and ways to solve them investigated. The factors limiting the business activity of construction organizations are highlighted and evaluated based on statistical data. Three main categories and corresponding specific factors of competitiveness of construction organizations analyzed. The method of expert assessments revealed the degree of their influence on the competitiveness of the organization. The ways of increasing the competitiveness of construction organizations, taking into account these factors, proposed.

Keywords: competitiveness, increasing competitiveness, factors of influence, construction organization, statistical methods, the method of expert assessments

The article discusses modern methods of conducting construction control (CS) as part of the implementation of the government program for digitalization of the construction industry. The prerequisites justifying the need for automation of the SC are presented. A review of the software used by Russian construction companies to transfer quality control processes into electronic format was carried out. Based on the completed review, a comparative analysis of the most significant and frequently used software functions is presented. The requirements for them have been formed. They are classified based on their integration into digital models of capital construction projects. This allowed the authors to develop an algorithm for conducting a QC taking into account all the requirements of regulatory documents and the interaction of the main participants in the construction process. It provides for automatic data transfer for the generation of as-built documentation in electronic form, the appointment of persons responsible for correcting defects, their photo and video recording with reference to the 3D model of capital construction projects.

Keywords: digital technologies, automation, regulatory documentation, as-built documentation, quality, construction processes, construction control, information model

The main properties of slag-alkaline binders were studied to determine their optimal composition. The possibility of controlling the properties of binders developed on the basis of phosphorus and blast furnace slag by introducing corrective additives into the aluminosilicate component of slag-alkaline binders, as well as by changing the type of alkaline component, has been experimentally proven. The conducted studies confirm the effectiveness of the use of sulfate-containing alkaline components for the production of slag-alkaline binders. As a result of the conducted experiments, slag-alkaline binders with an activity of 30 to 110 MPa were obtained. The possibility of regulating the properties of the developed slag-alkaline binders has been established. The required binding strength is achieved by adjusting the composition of the aluminosilicate component by introducing additives and the type of alkaline component.

Keywords: alkali-silk binders, slags, optimal composition, basicity, chromium peak, construction materials, reconstruction, work technology

This paper analyzes the shortcomings of the existing organizational and technological documentation, namely the construction organization project and the project of work production. It is concluded that the main task of organizational-technological documentation is to minimize construction risks at the earliest stage, to increase knowledge about the project and to transfer the process of development and decision-making to an earlier stage of construction. As a solution to these problems, it is proposed to consider the use of building information modeling technologies (BIM) in construction, and move to the development of digital construction organization project (4D model of the construction process), which is a digital information model of the capital construction object (3D model), the elements of which are interconnected with the work on construction production. Two projects where the building information modeling technology was applied and a digital construction organization project was developed are considered: construction of an underground tunnel and reconstruction of a power unit of a combined heat and power plant. The advantages of using a digital construction organization project are proved, which makes it possible to forecast the planned duration of works, as well as the duration of works, taking into account the occurrence of risk events, necessary resources and equipment.

Keywords: digital project of construction organization, 4D model, building information modeling, project of construction organization, capital construction object

This article is devoted to identifying and analyzing the main factors that influence the effective overhaul of medical institutions, which have a great impact on the quality of life of the population, but do not meet modern standards and new trends of the Industry 4.0 concept. During the study, a comparative analysis of regulations governing the overhaul of medical institutions was carried out, design and working documentation was studied, and practical examples of the implementation of such projects were analyzed. As a result of the study, the most significant factors influencing the effectiveness of capital repairs of healthcare facilities were identified. Identified factors include: the lack of a modern legislative framework on capital repairs, insufficient quality of project documentation, ineffective planning and execution of capital repair projects, and lack of consideration of innovative approaches and technologies. These factors entail a number of additional risks, leading to increased costs and timing of work, as well as a decrease in the quality of work performed. In conclusion, recommendations are presented for optimizing the process of carrying out major repairs of medical institutions, including a detailed study of regulatory documents in order to update them in accordance with modern needs, and the involvement of a technical customer for the purpose of control from the initial stage to the commissioning of the institution.

Keywords: major repairs, healthcare facilities, medical institutions, modern standards, project documentation

Technological pipelines of compressor stations are one of the significant types of basic equipment that ensures uninterrupted operation during gas transportation. In this article, we paid special attention to the issue of safe operation of the pipeline strapping of the gas treatment plant for transportation, which is designed to dry gas to the required parameters required by consumers and is one of the main technological units of the compressor station. During the operation of the adsorber lines with "hot" and "cold" gases, the pipelines of the regeneration line are subjected to high variable temperature loads. Thus, the operating organization faces the problem of ensuring sufficient compensation for the linear expansion of technological pipelines during their periodic heating. The calculation of the service life of the piping and its stability with a matched axial bellows compensator has been performed. Various solutions to the reliability problems of these compressor station components are considered and analyzed. It is concluded that it is necessary to update the regulatory design framework and introduce continuous technical monitoring methods into the operated facilities.

Keywords: gas treatment plant, process pipeline, adsorber, safe operation period, temperature load, compensator

the effect of a thickener and a setting retarder on the technological properties of GSHS START is investigated. One-factor plans of a two-factor model have been developed, with a minimum (0.1%; 0.005%) and maximum (0.2%; 0.05%) dosage levels of pore-forming and water-retaining additives, respectively. Regression equations of output parameters in the form of a second-degree polynomial are obtained using regression and correlation analysis of experimental data. The values of partial correlation coefficients are analyzed. With an increase in the dose of water-retaining and pore-forming additives from 0.1% to 0.2% and from 0.005% to 0.05% of the binder, respectively, for all possible combinations of the dosage of the thickener and setting retarder, there is an increase in setting time by 10 ... 72%, and sliding by 33 ... 80%. The least sensitive to an increase in water-retaining and pore-forming additives was a mixture in which the amount of thickener is 0.2% (at the upper level), and the amount of moderator is 0.04% (at the lower level).

Keywords: technological properties, organizational and technological solutions, dry building mixes, functional additives, thickener, setting, retarder, two-factor experiment, coefficient of determination, regression analysis, correlation analysis

Methods of calculation and design of building structures are considered that make it possible to provide trouble-free operation on time during the service life, and hence the level of reliability. According to the reliability indicator, the following scheme for standardizing the reliability of designed building structures is linked to the assessment of quality indicators of constructed structures. Indicators of design quality that are not related to strength, guaranteed with a given probability of failure-free operation, are introduced: geometric dimensions, modular deformation and elasticity, taking into account the properties of variability and technology. The appropriate safety factors are determined, ensuring mandatory protection of failure-free operation. A scheme for calculating design structures with the required level of reliability during the design, construction and operation of structures is being developed.

Keywords: method of calculation of structures, reliability, safety factor, strength class, reliability index, improvement of calculation of structures

The article discusses methodological approaches to assessing the quality of work projects (WPP). Based on an analytical review of modern scientific articles and regulatory documentation, it is shown that PPR is subject to a significant amount of uncoordinated requirements, both in terms of content and the availability of approvals for various conditions of construction sites. At the same time, projects are increasingly of a formal nature, the quality of technological solutions is decreasing, and third-party developers, so-called freelancers, are involved in their preparation. In this regard, the goal of the research work is formulated in the form of developing a methodology for analyzing the quality of PPR. Based on the analysis of various methodological approaches, it was established that it should be based on the assessment of various indicators obtained from projects drawn up for the conditions of specific construction sites, design features of buildings and structures being erected, etc. It is shown that the assessment of PPR should be carried out on the basis of a single, measurable, comprehensive criterion, which includes the following factors: ensuring safe working conditions at the construction site and the integrated safety of construction processes for the surrounding buildings; compliance with technological discipline requirements; compliance of the technology used with the specific conditions of the construction site; sufficient completeness of the project, completed on the basis of the requirements of regulatory documents. It is proposed to translate qualitative information characterizing these factors into quantifiable indicators based on their analysis using general definition tables.

Keywords: organizational and technological documentation, work project, quality, efficiency, general definition tables, incoming documentation control

The relevance of the topic of the article is due to the fact that currently there is no linking of the calendar plan to the schedule for the development of capital investments. The principle of constructing a schedule for the development of capital investments is proposed, which ensures the uniformity and proportionality of the use of financial resources. Schedules for the development of capital investments are constructed, each schedule for the development of capital investments corresponds to an image describing the change in the absolute value of the profitability of the investment and construction project. The use of a mathematical apparatus describing the movement of a material point can be used in the development of investment schedules and calendar plans for construction. The construction of construction schedules in the section of the construction organization project based on investment schedules will have a significant impact on the economic efficiency of investment projects.

Keywords: construction schedule, investments, return on investment, development of capital investments, duration of construction, efficiency of capital investments

The article synthesizes several approaches to the development of the social environment of neighborhoods and clusters, taking into account scientific developments in assessing the potential of territories in terms of building density, number of floors and capacity saturation of schools, preschool institutions and production areas. Options for implementing the strategy are outlined based on multi-product models for calculating capacity and scientific and production potential for the development of territories.

Keywords: cluster, quarter, region, potential, strategic planning, production capacity, multi-product models, building density, schematic map, optimization

Girderless ceilings have become particularly popular in the construction of civil buildings. However, it is often necessary to reconstruct them, namely, to strengthen the joint of the plate with the column. Both domestic and foreign researchers deal with the issues of punching. This scientific article is devoted to the study of the method of strengthening reinforced concrete floor slabs by adding transverse reinforcement.

Keywords: floor plate, punching, transverse reinforcement, reinforcement

Reliable and safe operation of oil and gas pipelines in the conditions of the Far North and Siberia is an urgent task facing the Russian Federation. It has the most important economic and strategic importance. The climatic and geological conditions of these regions suggest a high degree of risk associated largely with seasonal temperature fluctuations and oil pumping technologies, leading to freezing or thawing of the soil, the appearance of thawed permafrost waters. The purpose of our study was to analyze the influence of extreme natural and operational conditions on the design and spatial position of pipelines during the operation of the section of the CPS-2 - NPS Urengoyskaya highway. It was found out that the studied section of the oil pipeline has a predisposition to failures due to unfavorable conditions: meltwater, heaving soils, swampy territory. Technological calculations allowed us to conclude that at this stage the pipeline route meets all the conditions of strength and stability, i.e. the reliability of the pipeline is ensured.

Keywords: hydrocarbons, pipeline, melt water, underground laying, strength calculation, stability calculation, permafrost soils, spatial location

Information technologies and systems are a promising tool for solving a wide variety of problems in the development and implementation of construction projects at the present stage. Their active use makes it possible to reduce the cost and time of project implementation, as well as improve the quality of work performed by creating a modern and effective construction control system.

Keywords: information technology, digital building model, information modeling, design, construction process

The article on the design of student campuses is necessary in order to help architects and builders create a comfortable and convenient environment for students to live and study. It carries the main idea that when creating student campuses, it is necessary to take into account not only the social, psychological and cultural characteristics of student life, but also functional aspects. The campus should become not just a place to live and study, but a real community where students can find support and interact with each other, developing their skills and passions. In addition, the article allows you to better understand what new technologies and trends can be applied in the design of modern university campuses to make them even more convenient, innovative and environmentally friendly

Keywords: design, student campus, student dormitory, energy efficiency, landscaping, construction, self-sufficiency, materials, architectural solutions

The current legislative acts and regulatory and technical documents defining the requirements for the organization of the customer's activities are considered in the work. A review of studies with different approaches to the formation of organizational structures of the customer, depending on the types of construction, their volumes and features of objects, is carried out. The factors determining the requirements for the formation of organizational structures of the customer for various objects are highlighted.

Keywords: construction organization, technical customer, organizational structure, construction control, project approach

Capital construction projects include buildings and structures whose construction has not been completed. Currently, in the construction market, software developers offer more than 160 variants of construction information models (hereinafter BIM-model) for a complex cycle of building construction systems. BIM in design is not only a tool that supports modern technologies for investment and implementation of construction projects. Using BIM technology that analyzes the schedule of disbursement of funds and deadlines for the current dates, it is more convenient to control investment projects. It becomes possible to carry out electronic document management at all stages of the project cycle, launch digital construction control, add and adjust model attributes.

Keywords: information model, terms of reference, capital construction object, organizational and technological solution, BIM model, model element, monolithic structure, construction project implementation

The study is aimed at studying the corrosion processes of a metal waterstop inside technological seams in order to ensure its tightness and maintain performance qualities, since if corrosion occurs, the waterstop may lose its functional properties, which can lead to groundwater leaks. At the moment, there is no single source containing a complete set of information on corrosion processes in relation to metal waterstops, which leads to design errors, since it is extremely difficult to make the correct choice of metal waterstops, because it is impossible to analyze data and determine the parameters that determine the corrosion rate of metal waterstops in the technological concreting seam, it is necessary to take into account a large number of parameters related to the study of groundwater.

Keywords: waterproofing, technological seam, metal waterstop, corrosion processes, concrete, waterproofing system, ground water, carbonization, galvanized waterstops, copper waterstops, stainless steel waterstops

Often in practice, construction times are estimated using deterministic methods, for example, based on a network schedule of the construction plan with deterministic values for the timing of specific works. This approach does not reflect the reality associated with the probabilistic nature of risks and leads to a systematic underestimation of the time and, as a consequence, the cost of construction. The research proposes to use a Markov discrete heterogeneous Markov chain to assess the risks of non-completion of construction in due time. The states of the Markov process are proposed to correspond to the stages of construction of the object. Probabilities of system transitions from state to state are proposed to be estimated on the basis of empirical data on previously implemented projects and/or expertly, taking into account the risks characterising construction conditions in dynamics. The dynamic model of the construction plan development allows to determine such characteristics as: the probability of the construction plan realisation within the established terms, the probability that the object will ever be completed, the time of construction to the stage of completion with a given degree of reliability; unconditional probabilities of the system states (construction stage) in a given period of time relative to the beginning of construction. The model has been tested. The proposed model allows us to estimate the time of completion of construction, to assess the risks of failure to complete construction within the established deadlines in the planned conditions of construction realisation, taking into account the dynamics of risks.

Keywords: construction time, risk assessment, markov model, discrete Markov chain, inhomogeneous random process

By conducting a construction and technical expertise on the inspection of building structures and identifying several signs that can lead to their destruction, it is possible to identify a defect in which the destruction and accident of the structure under study is most likely to occur. It is proposed to use a Bayesian approach to evaluating the effectiveness of methods for determining defects affecting structural failure. The use of knowledge on the inspection and testing of building structures of buildings and structures is to determine the degree of relationship between the possible destruction of a building structure and its inspection, based on methods developed in the theory of reliability of technical systems. Based on the results of mathematical determination of the degree of malfunction, it is possible to more objectively assess the effectiveness of the method used to check the condition of the building structure. The method of using construction and technical knowledge to determine the technical condition of structures in an emergency state, in relation to the use of the Bayes formula, is considered. According to the proposed methodology, examples of determining the defect and the degree of destruction of building structures are given.

Keywords: construction and technical expertise, defects, reliability, diagnostic methods, wear, efficiency

Factors affecting the limited mineral resources of the planet and requiring the expansion of the raw material base of the construction industry are considered. The negative impact of overburden dumps on the ecological state of the habitat was noted. The importance of their processing into a useful product was emphasized in connection with the need to implement the industry program of the Russian Federation ""Involvement of overburden and containing rocks classified as production waste in economic circulation for 2022-2030."" The properties of sand and opoka as raw materials for making foam concrete were analyzed. The result of the analysis made it possible to formulate a list of restrictions, as a result of which it is undesirable to use opoku in concrete of a cast-in-place structure and a list of reasons, based on which it is possible to predict the feasibility of its use in foam concrete. The results of experimental studies are presented, reflecting the influence of the individual properties of sand and opoka on the density of foam concrete mixtures, the density of solidified foam concrete and the kinetics of their plastic strength during three hours of hardening from which it follows that replacing sand with opoka allows significantly improving the technological properties of foam concrete mixtures without compromising the achievement of their design density. It follows from the analysis of experimental data that the structural features of the foam concrete mixtures have a positive effect on the technological properties of foam concrete mixtures, which accelerate the gain of plastic strength of foam concrete mixtures after their placement into molds. The most important reason for the achieved result should be considered mesopores located in the volume of dispersed particles of aggregate from opoka. The established scientific facts make it possible to predict the expanded use of overburden rock - opoki in order to save resources in the construction industry and construction.

Keywords: resource saving, sand, opoka, foam concrete mixture, plastic strength

This article reveals a number of examples of the features of the construction of the base of a gravity offshore platform used for the extraction of hydrocarbons. The design of the reinforced concrete base of the platform in the form of a "monopod" consisting of 8 lower cylindrical tanks and a vertical reinforced concrete support with a length of 95 m is considered. Reinforcement of the entire structure was carried out by pre-tensioning reinforcement ropes on the hardened concrete in height by mechanical means. During the construction of the gravity foundation, new compositions of heavy high-strength modified concretes with the use of microsilicon and nanocarbon additives were used. During the construction process, adjustable formwork was used along the entire height of the structure.

Keywords: gravity platform base, monopod, pre-tension on concrete, high-strength modified concrete, towing, positioning

The article is devoted to the issues of optimizing the process of technical inspection of buildings and structures damaged as a result of emergency situations, using the most modern information systems and technologies. The difficulty in carrying out work on the inspection of buildings damaged as a result of natural and man-made emergencies necessitates the search for effective organizational and technological solutions in order to reduce the time required to carry out work on the inspection of buildings and structures without losing the quality and accuracy of the studies, as well as to create safe working conditions for specialists during work.

Keywords: technical inspection, emergency situation, digital building model, ground penetrating radar sensing, information technology, geographic information technology

The article views the process of preparing territories damaged by the war for housing stock restoration and it describes the main measures that need to be carried out in the damaged neighborhoods, depending on their degree of damage. These activities in the article are divided into two groups: the first for moderately damaged quarters, and the second for severely damaged quarters. The works from the first group are somewhat different from the ones in the second. For example, the decision to restore moderately damaged quarters requires temporary strenghtning and temporary protection of damaged buildings, while in severely damaged quarters, demolition of all buildings is required. In addition, the quantity of work in the second group is larger compared to the quantity in the first due to the need to demolish all buildings, dismantle all outdoor networks and lay new ones. However, the advantages of constructing works in these quarters are that it is possible to speed up the work due to the variety of implementation methods and the equipment that can be used.

Keywords: post-conflict reconstruction, demining of territories, preparatory works, technical condition of damaged buildings