Introduction. It is the first analysis and presentation of the materials on surveys conducted in the pipe rolling workshops of the Tagmet JSC since 1995. The investigations were carried out after the collapse of four roof spans with a total area of 14 thousand square meters. Research Institute of Building Constructions named after V.A. Koucherenko was actively involved in clarifying the causes and eliminating the consequences of the accident for one year. After that the institute's specialists for a long time conducted inspections of the plant's workshop structures in order to issue conclusions on their industrial safety and recommendations for repairing and strengthening worn and damaged elements of building structures for their further safe operation. One of the objects to be surveyed in 2008 was the so-called "Crystal section", which was part of the buildings of pipe welding workshop No. 3 of the Tagmet JSC.

Aim. To show one of the ways to possible strengthening of the structures of industrial buildings on the base of the results of a survey of mixed structures, calculations and analyses of their load-bearing capacity reserves.

Materials and methods. Visual and instrumental inspections of the technical condition of building structures, analysis of drawings, photographs, plans, etc.

Results. As a result of visual and instrumental surveys of the technical condition of building structures of buildings of the "Crystal section" TSC-3 during the inspections and examination of industrial safety of structures of buildings of the Tagmet JSC plant, defects and damages exceeding the values established by current regulatory documents and affecting the operational suitability of the building were revealed.

Conclusions. Scientific and technical support for strengthening of the structures of the workshops of the Tagmet JSC, the recommendations of specialists made further safe operation and continuous increase in the commodity productivity of the plant possible.

Introduction. Overlapping reinforcement joints in monolithic reinforced concrete structures are the most common, because they have sufficient simplicity and low labor intensity when installed on a construction site. When designing such joints in structures subject to compressive load, questions often arise related to the need to arrange an increased overlap length of compressed reinforcement in accordance with the requirements of domestic regulatory documents.

Aim. The aim of the work is an analysis of modern design practice, as well as available experimental studies of the bearing capacity of compressed reinforced concrete elements with overlapping reinforcement joints located in the same design section.

Materials and methods. The analysis was carried out by studying the provisions of domestic and foreign regulatory and technical documentation, as well as the results of experimental studies available in the public domain.

Results. The data on the methods available in the design practice for determining the overlap length of compressed reinforcement are systematized, including the case, when the joints are located in the same design section.

Conclusions. Based on the results of the work, the existing approaches for assigning the length of the overlap of compressed reinforcement located in the same design section of reinforced concrete structures were analyzed. The methods adopted in Russian and foreign regulatory and technical documents, as well as experimental research on this topic, are considered. Based on the results of the analysis of the available data, it can be said that additional studies to assess the effect of the overlap length of the compressed reinforcement on the strength of reinforced concrete elements can optimize their design solutions – without reducing the required level of reliability.

Sustainable construction technologies, which today form the trends in the development of the global construction industry and related economic, political, environmental and social aspects, are firmly based on the principles of implementing the main directions: durability, climateefficient construction, carbon neutrality, energy conservation, energy efficiency, resource conservation, recycling.

The concept of tomorrow is precast concrete construction systems, unique in their content and individuality, capable of providing reliable design, high profitability, high requirements for indoor climate and energy balance of buildings.

The article highlights the GREEN CODE system – one of the modern industrial technologies of precast concrete, which allows you to build buildings and structures in accordance with the trends in the development of the global construction industry. In production and construction logistics, the GREEN CODE system has a higher potential for economic efficiency than traditional construction methods, and allows additional resource savings.

Introduction. Plasters are still one of the most popular materials for finishing of facades of buildings. Modern plasters are produced mainly in the form of ready-to-use dry mixes. Manufacturers set themselves the task of obtaining not only plaster mixtures meeting standards, but also having hydrophobicity, low density, thermal conductivity and other features that determine the functionality of the plaster coating. In this regard, there is a need to develop and implement plaster mixtures based on new types of light aggregates.

Aim. To conduct comparative studies of the physical and mechanical properties of a light plaster mortar using the "SPADAR" foam ceramic granules and plaster mortars with similar fillers as a light filler.

Materials and methods. The research was carried out on light plaster mortars using as light fillers: "SPADAR" and foam ceramic granules from another manufacturer ("KERWOOD"), foam glass granules, expanded perlite sand. The parameters of density, strength under axial compression, water absorption during capillary suction and thermal conductivity of a light plaster mortar in a dry state were studied. The tests were carried out according to standard methods.

Results. The comparative technical characteristics of the studied plaster compositions are determined. During the analysis of the data obtained, the advantages of plaster compositions using foam ceramic granules as a light filler were revealed. Based on the data obtained, the composition of a light plaster mortar with a density of up to 700 kg/m³ using the "SPADAR" foam ceramic granules was developed.

Conclusions. The composition of the plaster based on the "SPADAR" foam ceramic granules turned out to be the most effective by the obtained values of the studied characteristics in total. In many ways, the obtained values of the technical characteristics of this plaster studied in this work are provided precisely by the "SPADAR" foam ceramic granules. Based on the results obtained, it is necessary to investigate other properties of the developed compositions of light plaster mixtures (adhesion, vapor permeability, moisture-proof properties with respect to the mineral base, frost resistance, etc.).

Introduction. The calculation model of the strength of slabs during punching, adopted in domestic regulatory documents, contains a number of contradictions to the physical side of the process. So it is known from experience that even before the moment of destruction, many cracks develop in concrete. Therefore, its tensile strength, which is the basis of the current model, is exhausted long before the destruction of the structure. The current model does not take into account the longitudinal reinforcement of the slabs, which is one of the main factors in ensuring strength during penetration. There are similar disadvantages in foreign models. The accuracy of normative calculation methods, both domestic and foreign, is low.

Aim. Creation of a method for calculating of the slabs for punching, which correctly takes into account all known features of the structure and has high accuracy.

Materials and methods. The method of calculating of the strength of slabs for penetration is considered, which is based on the condition of equilibrium of moments of external and internal forces, in contrast to the normative method, which considers the equilibrium of projections of all forces on the vertical axis.

Results. A calculation method has been developed that does not contradict the known experimental data on the operation of slabs during punching. It was possible to correctly take into account the work of the longitudinal reinforcement of the slab. The high accuracy of the proposed calculation method is shown.

Conclusions. The conducted research allows us to take a fresh look at the essence of the punching process. The mechanism of destruction, which has fundamental differences, is considered. The proposed calculation method allows us to obtain results comparable in accuracy with the best numerical models.

On September 26, 2024, after a short illness, Yuri S. Volkov, Candidate of Technical Sciences, Honorary Builder of Russia, honorary member of the Russian Academy of Architecture and Building Sciences, Scientific Secretary of the Research Institute of Concrete and Reinforced Concrete named after A.A. Gvozdev, JSC Research Center of Construction, member of the editorial board of the journal "Concrete and Reinforced Concrete", died suddenly.