The article presents the results of a numerical experiment to determine the effect of non-removable void generators on the strength of monolithic reinforced concrete floor slabs clamped along the contour. The experimental samples are made in the form of spatial models using volumetric finite element models in the LIRA-CAD software package. The tests were carried out on 4 series of samples, differing in terms of dimensions and reinforcement. Detailed descriptions of the dependencies used and the laws of deformation of materials during the construction of models are given. The values of compressive stresses in concrete and reinforcement, as well as tensile stresses in reinforcement obtained as a result of tests, were subjected to comparative analysis. Based on the conducted experiment, it was found that the use of non-removable voids in a monolithic reinforced concrete slab does not reduce its strength, while reducing concrete consumption by 18.3-23.1%.

The paper presents a physical and computational model for determining the parameters of limit states of reinforced concrete structures under complex stressed state - bending with axial and shear forces. Based on the adopted scheme of cross-section discretization and A.R. Rzhanitsyn's theorem of duality between force and deformation parameters, the forward and backward transfer for determining the coefficients of the stiffness matrix of reinforced concrete rod structures with inclined and normal cracks have been constructed. Stiffness of structures in the zone of inclined cracks is determined using the model of composite strips which separate the zone with inclined cracks. The hypothesis about the character of deformation distribution in a complex-stressed reinforced concrete element with inclined cracks is accepted.

For this model the conditional shear modulus is obtained, which allows to determine the average relative linear and angular strains of concrete and reinforcement at the point adjacent to the shear joint between inclined cracks. Based on this model and using the experimentally obtained value of the relative shear in the inclined crack, the dowel forces in the reinforcing bar intersected by the inclined crack were determined. The application of the obtained analytical relationships in the practice of designing reinforced concrete structures allows not only to clarify significantly the definition of displacements and width of opening of inclined and normal cracks, but also to maximize the convergence of the design and physical model based on experimental data.

It is well known that imperfections are always present in structural elements. Imperfections can significantly affect the behavior and bearing capacity of steel structures, especially in the case of stability-related tasks. Therefore, inconsistencies must be taken into account in the loadbearing capacity model and their correct application (setting the shape and value) is a key point in the numerical analysis process. In recent decades, much attention has been paid in the domestic scientific space to updating imperfection models for use in numerical models, including taking into account modern more accurate manufacturing and installation technologies for steel structures. The purpose of this study is an analytical review and analysis of scientific research and technical literature, followed by synthesis and elaboration of recommendations on imperfections in relation to the calculation of steel structures using computer modeling technology, including the finite element method. The results of the study contain instructions on how to set the shapes and values of imperfections for different groups of imperfections. The article consists of two parts. The first part is devoted to the study of geometric imperfections, residual stresses and rules for the combination of imperfections, the second part of the article is devoted to equivalent imperfections.

Load-bearing masonry is quite widespread, including in earthquake-prone areas and zones in which military operations were carried out. At the same time, the existing treasure models, as well as reinforcement technologies, are mainly focused either on strengthening in order to increase the load-bearing capacity, or on restoring structures damaged during operation, actually static loads. Complex retrofitting methods, as well as models of reinforced masonry that have been damaged as a result of seismic or mine-explosive impacts, for the most part are not focused on mass use and imply mainly the re-laying of destroyed areas. At the same time, there is a need to adapt existing high-tech methods of strengthening masonry structures for mass use, taking into account the latest developments in the field of materials science. The most optimal variant of reinforcement, according to the authors, was the use of single-sided shotcrete applications. For this method, a model of reinforced masonry was defined and described in order to carry out a calculation justification and a comprehensive calculation and design methodology was developed, including for load-bearing multi-storey buildings structures. On the basis of laboratory studies, a constructive solution for fixing applications was justified only due to the forces of adhesion to the surface of the base masonry. The specified complex technique was adapted on real objects of multi-storey buildings with load-bearing masonry walls.

CLT panels are made by gluing several layers of boards crosswise, which provides them with high load-bearing capacity and bending resistance. In addition to the number of layers in the panel, the deformability and bearing capacity are influenced by the geometric parameters of the plate, the way the layers are attached to each other, the way the structure is supported, etc. Due to the fact that the material has recently been used in construction, many issues remain poorly understood, and therefore there is an opportunity and need to optimize some aspects both in the CLT panels themselves and in the way they interact with other building structures.

In this article, the influence of the pitch of boards in the transverse layer on the deformability and stress distribution in a three-layer CLT panel rigidly pinched on both sides was studied. Numerical studies of the finite element method (FEM) were carried out using the computing complex SCAD+. The computational model of the plate in this study is a composite orthotropic plate with rigid connections between the layers. The result of the study is numerical data reflecting the dependence of the distribution of normal stresses OX and OY and the transverse deformation of the plate on the pitch of the lamellae (boards) in the bottom layer. Projections of the computational model with normal stress isofields on the stretched and compressed plate layer are also obtained. This makes it possible to identify general patterns of stress distribution and deformation changes with variations in geometric parameters for this type of support for their use in the design of building structures using CLT panels as well as in the optimization of the structure in order to increase the cost efficiency of resources.

Under emergency situations associated with sudden failures of the load-bearing elements of the structure, torques may additionally occur in the columns due to the specifics of the structural design of the buildings. Thus, the columns may be in a complex stress-strain state. The objective of this study was to develop a semi-analytical design model for analysis of the stability of reinforced concrete columns subjected to compression with torsion as a result of an accidental action. For achieving the objective, authors formulated the initial hypotheses, developed the determining equations for calculating the stability of a reinforced concrete column subjected to compression with torsion. To validate the reliability of the proposed model, it has been compared with the results of modeling in the software complex Ansys. Analysis of the data showed that the largest difference between the results was up to 8.08% for the case P = 0.4·P_cr,e = 126.6 kN. The smallest difference of 3.6% was for the case P = 0.9·P_cr,e = 284.85 kN. It has been shown that as the torque increases, there is a decrease in the value of the critical force causing loss of stability. This is due both to the action of the torsional pair of forces during the distortion of the rod and to the decrease in the mechanical properties of concrete under the combined action of normal and tangential stresses.

The article describes the probabilistic approach of reliability analysis for steel truss bars with imprecise statistical data. An approach to recovery the probability density of a random variable by the kernel density estimation method is illustrated for a small number of tests/measurements cases. The estimation of the distribution density parameters is presented in an interval form, which makes it possible to form a p-box for the random variable. Evaluation of the probability of non-failure allow to get a quantitative assessment for the safety of steel trusses, to identify the most unreliable trusses for monitoring their technical condition or to calculate the effect of strengthening the truss according to the reliability criterion. The probability of non-failure is estimated in the interval form. If the lower limit of the interval does not allow to get a conclusion about the truss safety level, then it can be increased by obtaining additional statistical data or by strengthening the truss or reducing the permissible load.

In the professional environment of architects, there is concern about the formation of a trend of reconstruction and renovation of buildings and structures in large and major cities in order to develop urban infrastructure. The underestimation of the contribution of Soviet architecture to the cultural heritage of post-Soviet countries and countries of the socialist camp is noted. At the same time, the "new architecture" forms the urban environment under the stereotypes of homologation, which does not correspond to the socio-cultural demand of the glocalization of "digital nomads" seeking to live in eco-digital cities. The obsolescence of the "new architecture" is observed already at the project stage or in five years. In Moscow, the reconstruction program includes 39 Soviet cinemas in the peripheral zone of the city. Public and shopping complexes with underground levels are being built on the site of these cinemas. The article classifies the types of projects of Soviet cinemas and shopping centers, and also forms diagrams for their qualitative comparison. This eventually made it possible to evaluate the architectural and artistic contribution to the Moscow development of both Soviet cinemas and new shopping complexes, the continuity between them and differences in design principles.

The urgency of the problem associated with the use of injection erection technology of soil cementation in various engineering and geological conditions is substantiated. Due to the peculiarities of cementation technologies under various modes of injection impregnation and the possibility of applying certain technical injection parameters for different types of soils, it is possible to improve various deformation characteristics of the soil mass when implementing the technology. Some results of the analysis of the work of injection cementation of soils in dispersed soils are presented and general patterns are established under which it is necessary to adjust the parameters of cementation. The theoretical prerequisites are considered in relation to experimental data, the effectiveness of the application of cementing technology in the injection impregnation mode is proved and the general applicability of the application of these cementing methods with an increase in the technical indicators of the fixed soils is established.

The article considers creation of elastic self-adhesive radio absorbing materials for frequency range of 2-7 GHz. Carbonyl iron is widely used in the production of radioabsorbing materials. Materials with this filler have a low absorption of electromagnetic radiation, and more reflect it. The main advantage of this filler is that it is produced by domestic manufacturers in industrial volumes. Another filler used for the production of radioabsorbing materials is carbon fibre. Materials on this filler have a high absorption coefficient of electromagnetic radiation, but operate in a very narrow frequency range. Therefore, in order to increase electromagnetic absorption and extend the frequency range, a certain amount of carbon fibre is introduced into the composition of the radioabsorbing material containing carbonyl iron. It is shown that in this case absorption of electromagnetic radiation reaches 93%. The material is intended for protection of premises and equipment against electromagnetic radiation.

In the modern construction industry, the problem of finding materials with increased stability that would provide minimal environmental impact with optimal economic efficiency is urgent. Considering global trends in the field of ecology and sustainable development, attention is focused on recycling and reuse of industrial waste. Of particular interest is the pulverized material formed during the operation of asphalt concrete plants. In this paper, the potential of integrating this type of waste as an alternative construction resource is studied. This article focuses on the urgent need to adapt the principles of sustainability in construction practice through the integration of materials with minimal environmental footprint. The key aspect of the study is the concept of recycling of pulverized waste from asphalt concrete production, which can help optimize the resource potential and reduce the environmental burden on the ecosystem. The study examines various dust compositions obtained from asphalt plants of different operating principles. The morphology of particles and the bitumen capacity parameter were investigated. It was found that by replacing up to 50% of mineral powder with carryover dust, there can be a significant environmental and economic impact for the road construction industry.