Introduction. In previous publications, the authors examined the features of calculating the strength of normal sections of reinforced concrete structures associated with the possibility of using two approaches – the nonlinear deformation model (NDM) and the method of limiting forces (MLF). Using specific examples, the results obtained with both approaches are compared. Cases of significant discrepancies in the consumption of selected reinforcement have been identified, trends have been explained, and the physical essence of the phenomenon has been analyzed. Calculations were performed according to the OM SNiP Reinforced Concrete program.

Aim. To analyze the implementation of features when using various computer programs for calculations of reinforced concrete structures, identify differences in results, establish their physical cause, evaluate economic aspects and problems, and make the necessary recommendations.

Materials and methods. The studies were performed for three types of structures. The first type included four sections of elements under two stress states: off-center compression (rectangular and annular) and oblique offcenter compression (rectangular and I-beam). The second type of structures included columns and pylons of a projected and constructed reinforced concrete building. The third type was an illustrative example – the T-section of the bent element at different operating moments and percentages of reinforcement. Calculations of the first type of structures were carried out by the authors by the OM SNiP Reinforced Concrete program, as well as the program developers of the Ing+, Arbat, Lira-SAPR, Lira 10, STARK ES programs. The calculation of structures of the second type was carried out by the authors by the OM SNiP Reinforced Concrete program and the designers by the Lira-SAPR 2022 program. The test example was calculated by the authors according to the OM SNiP Reinforced Concrete program.

Results. When calculating according to the NDM, a significant unjustified overspending of the required reinforcement was revealed compared to the calculation according to the MLF. In an illustrative example, the overspend is 220 %.

Conclusions. The general state of calculations of reinforced concrete structures should be recognized as requiring adjustments. To obtain a multibillion-dollar economic effect, it is proposed to provide in SP 63.13330.2018 two equal approaches to the calculation of normal sections of reinforced concrete structures - NDM and MLF. It is advisable to develop a document with a set of reference examples that allows you to get the same results for different programs with the same source data.

Introduction. The material of the article considers the strength characteristics of ceramic and concrete masonry products, the operation of which is carried out in difficult conditions. The analysis of domestic and foreign publications and sources carried out in this work, including the results of previously performed experiments and field studies, showed that the values of the tensile strength of concrete and ceramic masonry products largely depend on moisture saturation.

Aim. When analyzing previously performed works, it was found that moisture saturation and operating conditions significantly affect the strength properties of concrete and ceramic masonry products in the form of bricks and small blocks. It is noted that in some cases, the effect of degradation of the physical and mechanical properties of the products was observed. When performing surveys of buildings and structures, it becomes necessary to determine the bearing capacity of the masonry of foundations and basement walls located below the mark of the adjacent ground surface. These structures are located in an environment of excessive humidity, therefore, the masonry products themselves are in a state of increased moisture saturation, for example, due to the absence or damage of waterproofing, violation of the heat and humidity regime of the indoor microclimate.

Materials and methods. During the work, masonry ceramic products in the form of bricks were used – new ones made according to State Standard 530-2012; historical bricks selected during the inspection of buildings and structures of historical buildings, as well as concrete wall products made according to State Standard 6133-2019. The test procedure complies with the established standard State Standard R 58527-2019.

Results. Conducting of the research and developing of methods to assess the effect of humidification of ceramic and concrete masonry products on the strength of masonry is important for assessing the reliability of buildings and structures.

Conclusions. The current problem requires comprehensive studies of the strength characteristics of ceramic and concrete masonry wall products, taking into account the influence of humidity.

Introduction. This paper provides materials justifying the introduction of a new constructive solution for the reinforced concrete protective shell of a nuclear reactor in a prefabricated and monolithic design.

Aim. Among the tasks that were set during the development of the constructive solution, the main one was to ensure the work of reinforced concrete for compression under all types of loading and the perception of tensile forces by ropes that are in a free state, available for maintenance and operation.

Materials and methods. The calculations were performed by the finite element method using a software package MicroFe-StaDiCon for calculation of the spatial structures for strength, stability and vibrations.

Results. A fundamentally new constructive solution has been developed for the protective shell of the nuclear reactor of the NPP, consisting of reinforced concrete elements in the form of cylindrical folds with a bulge directed towards possible external and internal force emergency effects, including the explosion of the reactor. Variants of protective shells have been developed with the elaboration of fundamental technical solutions for unified folded elements made of reinforced concrete with the possibility of their monolithic and prefabricated manufacture. A scheme of open arrangement and tensioning of cable bundles with tension transfer to pre-fabricated structures of the inner and outer parts of the protective shell is proposed.

Conclusions. This design solution provides compressive forces in reinforced concrete of the folds of the inner and outer parts of the protective shell from the load during loading, which prevents the formation of cracks in them. The tensile forces in the shell are perceived by the prestressed reinforcement located inside its structure, free for maintenance and control. In the process of work, fundamental solutions have been developed for the structural nodal joints of prefabricated folded reinforced concrete elements, technological holes in the shell structure and the implementation of prestressing in it. A comparative technical and economic analysis of the proposed and existing inner protective shell showed the possibility of reducing concrete consumption by 1.5–2 times, non-stressed reinforcement by 3–4 times, construction time by 4 times.

The "Strategy for the development of the construction industry until 2030 and for the future until 2035" developed by the Ministry of Construction of Russia indicates that one of the goals of construction development for this future is to "reduce the carbon footprint from the impact of the construction industry on the environment. The article analyzes the factors that allow the main building material - concrete to make a significant contribution to reducing the carbon footprint in relation to the environment. Examples of European practices in solving this problem are given, the need for appropriate research work is indicated regarding the assessment of the impact of cement and concrete production on increasing the carbon footprint, the development of methods to solve this problem and taking this factor into account for practical needs.

The analytical review of 2023 was prepared based on the analysis of materials and publications of the Beton GmbH information center (Germany).

Concrete construction, concrete and reinforced concrete technologies, carbon neutrality, and resource efficiency are the central topics that the Beton GmbH (IZB) information center is working on today on behalf of German cement and concrete manufacturers. As an analytical platform for manufacturers and the driving force of the industry, the center promotes new applications of cementbonded building materials and introduces innovative products and processes. Given the critical importance of cement and concrete in construction, the industry also has a special responsibility to mitigate the effects of climate change. Therefore, the German cement industry has been actively working for many years to reduce carbon emissions and conserve natural resources. Using innovative technologies, Germany plans to produce cement and concrete with zero carbon emissions by 2045.

An important element of the promotion and training of sustainable concrete construction is the provision of technical advice to builders, contractors, architects and engineers in the field of civil, road, high-rise and agricultural construction. The main focus is on concrete and processes that provide sustainable, reliable solutions, as well as contribute to the implementation of major planned ideas in accordance with the main global trends: climate efficiency, resource conservation, energy conservation.

Introduction. In construction science, the name of Professor Boris Grigoryevich Skramtaev is widely known to the engineering community of the country and far beyond its borders. He actively participated in the formation and development of the Russian scientific school of concrete and reinforced concrete. The construction industry actively implemented the innovation of researcher Skramtaev and his colleagues, using precast concrete proposed by scientists on large-scale construction sites, introducing new types of cements developed by them for the construction of residential and industrial facilities.

In Boris Grigoryevich's informative biography, in addition to research on hydraulic engineering, coarse-porous and high-strength concretes, participation in the development of inorganic binders is vividly reflected. He devoted a lot of time and effort to leading research teams, the results of which are impressive by today's standards. Thus, during the difficult for the country war period, scientists under the leadership of Professor Boris Grigoryevich Skramtaev contributed to the full and timely provision of domestic industry with building materials, primarily high-quality concrete and reinforced concrete, even in extremely difficult periods for the construction industry during the Great Patriotic War and the post-war restoration of the national economy.

The aim of this article is to conduct an author's analysis of the fruitful scientific activity of Professor B.G. Skramtaev, to confirm his talent as a leader of research teams. To trace the biography of the outstanding Russian scientist Boris Grigoryevich Skramtaev, the founder of the Russian school of reinforced concrete, who made a great contribution to the creation of modern building materials, various types of concrete, which were actively used in the construction industry.

Results. The article examines and analyzes the newly discovered biographical data about Professor B.G. Skramtaev, analyzes the influence of the environment in which the scientist's worldview was formed, the motives of his active and fruitful activity in the field of concrete science. For the first time, the responses of representatives of the scientific community and heads of interested ministries of the country about B.G. Skramtaev's popular textbook "Building Materials", which has undergone five reprints, has become a reference book for several generations of students and engineers.

Conclusions. The source base of the research has been expanded, archival documents and materials that were previously unknown or little known to the scientific community have been introduced into scientific circulation. Several materials have been found confirming the heuristic outstanding abilities of researcher B.G. Skramtaev in the field of concrete science.

The role and place of scientific activity of Professor B.G. Skramtaev as a theorist on the creation of new promising concretes and mixtures for the construction industry are determined.

In the article, the scientist B.G. Skramtaev is shown as a versatile and in-depth researcher, the author of numerous textbooks and monographs, relevant articles on the topics he studies. For example, his 1952 textbook "Building Materials" reflects the priority of Russian science and technology more fully than previous editions. It presents the achievements of Soviet construction materials technology and changes in outdated terminology on building materials. The fifth edition provides new data on materials and reinforced concrete parts for prefabricated construction, takes into account the basic principles of the draft Schedule, replenishes the section "Achievements of domestic science and practice", reflects the works successfully implemented in practice in 1950–1952, including personal works of the authors, especially in the field of new cements, concrete technology and building solutions.

The conclusions obtained as a result of the analysis of the material contribute to the study of the originality of the versatile personality of B.G. Skramtaev, his phenomenon in scientific thought in the field of concrete science and building materials in the period of the 1930s–1960s.