The massive restoration of buildings and structures after seismic impacts and in combat zones with the characteristic consequences of mine and explosive damage requires particularly effective methods of strengthening structures, which necessitates the development of appropriate regulatory and methodological justifications for these techniques. These solutions should primarily be based on experimental studies conducted on field samples close to real samples, and impacts that also correspond to actual structural loading patterns. In this regard, it becomes a question of choosing test methods, taking into account important factors in this case: repeatability and similarity, as well as the possibility of scaling if it is impossible to conduct tests on samples with dimensions close to real ones. The issues discussed in this article are devoted to the choice of methods for testing masonry structures after damage caused by equivalent seismic and mine-explosive effects, and a specific test proposal has been developed. 

The article presents a novel computational framework for developing constitutive models of reinforced concrete (RC) behavior, based on the concept of a Representative Volume Element (RVE) for simulating characteristic complex stress states in structural members. The framework is founded on the idea of block-based physical models of material response, combining the energy approach of fracture mechanics for cracked RC with deformation models of reinforced concrete theory. To determine the stiffness and crack resistance of RC members in regions subjected to combined bending moments and shear forces, a "single composite strip" model within cross-sections containing inclined cracks is proposed. The opening of normal and inclined cracks is simulated using RVEs represented by a reinforced prism and a double-cantilever element (DCE), respectively. The stress-strain state in the vicinity of a crack is determined taking into account a deformation effect in the fracture mechanics of RC, discovered by the author. 

Deformations of a clay soil sample are a consequence of shearing along sliding surfaces. The sliding surface front, moving in the loaded soil body, is slowed down by deformation heterogeneities. Overcoming the elastic resistance on them occurs with a displacement jump. Displacements on a group of deformation heterogeneities cooperatively manifest themselves in the form of a jump in the soil sample's settlement under compression. Deformational heterogeneities are represented, within the framework of a 2-component deformation model, by the largest rigid inclusions in the matrix of clay particles and microaggregates. The schematic diagram shows the relationship between the displacement of the sliding surface and the compression deformations of the sample, as well as the mechanism of stepwise settlement and the cyclicity of the settlement rate. The effect of stepwise settlement is observed both during the loading of the sample and during creep. Overcoming viscous friction in the clay matrix and elastic resistance on deformation heterogeneities causes the physical sliding surface to deviate from the surface of maximum tangential stresses, which creates the effect of internal friction.

The risk of accidental damage to buildings is currently increasing. This makes traditional design strategies, which focus on eliminating such impacts or designing key elements, ineffective and economically unreasonable. The most promising approach is to ensure the robustness of structures by limiting the extent of collapse after initial local failure. The goal of this study is to develop a calculation model for the resistance of a beam support section of a reinforced concrete frame under multi-level deformation in an accidental situation. The rationale for selecting a physical resistance model in the form of a structural node with support sections of beams and columns is explained. A calculation model has been developed to determine the resistance of support sections of beams in a reinforced concrete frame building under multi-level deformation in an extreme state resulting from an accidental situation. Analytical expressions have been obtained for the characteristic points of the "moment-rotation angle in a plastic hinge" diagram for flexural and compressive arch action, as well as for the "axial force-elongation" diagram for tensile catenary action. The proposed approach enables the evaluation of the load-bearing capacity of reinforced concrete frames under extreme conditions resulting from accidental events. The results of the study can be used to design structures that are more robust.

This article is the second in a series devoted to summarizing and analyzing numerous published materials on the thermomechanical properties of concrete exposed to high temperatures. This article provides an overview of experimental data related to the study of concrete properties under shortterm heating and attempts to analyze and structure the results of numerous, diverse tests related to the study of concrete properties under short-term high-temperature heating. The physics of concrete deformation during heating and its causes are discussed. The dependence of the obtained characteristics on test conditions is demonstrated. The key factors influencing the strength and deformation properties of concrete during heating are highlighted. Concepts regarding the mechanisms of thermal degradation and thermal resistance of concrete are developed, supported by specialized methods for studying concrete and its components. The main causes of changes in the strength and deformation properties of concrete during short-term high-temperature heating are presented, with an emphasis on identifying the influencing factors and their degree of influence, as well as summarizing existing interpretations of degradation mechanisms.

The paper considers the buildings of secondary schools of the current school fund of the Belgorod region, which need renovation to form modern full-day educational complexes of a new generation on their basis. School construction in the region flourished in the 1960s and 1980s, during which time new schools were built especially intensively in rural areas. Today, the buildings are outdated, and recently some of them have been modernized or overhauled, but many continue to operate as they were, which does not meet the current requirements for organizing educational activities, including extracurricular activities. The material and technical base of school buildings and their outdated spatial environment do not have the necessary conditions and space resources to expand the extracurricular function. There is a contradiction between consumers' demands for the content and conditions for obtaining basic and additional educational services at school and the limited possibilities of the architectural and planning structure of existing school buildings. This contradiction is a characteristic problem both for the Belgorod region and for other regions of the Russian Federation — a transition from a monofunctional school to a multifunctional full-time educational complex is necessary. In order to solve the problem, techniques and methods of renovation of obsolete school buildings have been studied, and the main trends in school design and construction have been identified (based on international experience). The analysis of the existing typology of regional schools made it possible to identify the main compositional schemes of buildings necessary for the design of additional block modules of extracurricular centers and their introduction into the structure of new complexes during renovation work. The expediency of introducing alternative functions into a monofunctional school building is due to current trends in the development of architecture in general education buildings and full-time complexes and sociological research conducted within the framework of this work. A strategy for the renovation of schools into full-day educational complexes, based on a modular approach and taking into account the established typology of buildings of the regional fund, is proposed for discussion; a variable range, functional and architectural planning organization of block modules of extracurricular centers using elements of sustainable architecture is proposed; an experimental design solution for a full-day educational complex with block modules is proposed extracurricular centers of various types. The renovation strategy proposed by the authors of the work will make it possible to quickly and efficiently modify and modernize existing school buildings, which is especially important in the context of the loss of a significant part of the regional fund and represents the shortest path for the transition from outdated to modern architecture of new-generation educational complexes.

This article is devoted to identifying the fundamental principles and techniques for managing urban coloristics and developing the color design of public spaces. This is considered in the context of socio-cultural factors, the structural-morphological basis of architectural and urban form, the color dynamics of the natural setting, and other elements that contribute to a city's unique character and its visual color identity. The authors define the key principles and techniques capable of significantly influencing the formation of the color environment in a city's public spaces and the uniqueness of its color image in the design of its object-spatial and architectural environment. It is concluded that applying these principles for shaping the color environment of urban public spaces will enhance and optimize the process of designing the coloristics of the city's object-spatial and architectural setting.

A study was conducted on the use of opoka from the Shipovskoye deposit in the Republic of Kazakhstan and thermolite obtained from opoka in road construction. The aim of the study is to develop new technologies for the production of building materials - opoka and thermolite, and their use in road construction. The object of the study is opoka from the Shipovskoye deposit in the Republic of Kazakhstan. The subject of the study is the properties of opoka and thermolite and their work in the composition of the road pavement of category III highways. Scientific hypothesis - opoka from the Shipovskoye deposit in the Republic of Kazakhstan can be used as an independent material or as a thermolite in the composition of the road pavement of category III highways. Scientific novelty - using modern research methods, new data were obtained on the physical and mechanical properties and meneralogical composition of opoka from the Shipovskoye deposit; new data were obtained on the physical and mechanical properties and chemical composition of thermolite obtained from opoka. The theoretical significance of the study lies in obtaining experimental data on the properties of opoka and thermolite, the practical significance of the work lies in using the research results to develop the composition of asphalt concrete mixture based on thermolite and its application in road construction. The main physical and mechanical properties of opoka from the Shipovskoye deposit in the West Kazakhstan region were established. The use of opoka in the construction of a road on the section Uralsk (Republic of Kazakhstan) - the village of Ozinki (Russian Federation) was studied. As a result of the work carried out to study the state of the road section after six years of operation, the advantage of using opoka for the construction of the road base was established compared to clay. A technology for producing thermolite was developed, for which a product quality certificate was received based on the results of the tests. The development of a technology for the production of asphalt concrete mixture based on thermolite for road construction, especially in those areas where there are no deposits of hard rocks for the production of crushed stone, is very relevant. An asphalt concrete mixture composition has been developed using thermolite, which has an advantage in terms of indicators compared to existing analogues, which is confirmed by the results of tests conducted in accredited testing laboratories, permitting the use of the developed asphalt concrete mixture composition for the construction of road surfaces of category III highways. 

During the operation of buildings and structures, reinforced concrete structures are exposed to various loads that cause deformation and failure. The strength and elastic-plastic properties of modern concrete are controlled by introducing plasticizers, nanoadditives, and fillers. The biostability of composites is enhanced by adding biocidal additives. This article examines the deformation and failure of cement compositions modified with biocidal additives to create durable powder-activated concrete—a type of next-generation concrete. The potential of using guanidine-based compounds as a fungicide additive has been experimentally demonstrated. The key characteristics of concrete deformation processes are determined using stress-strain diagrams. Complete stress-strain diagrams for biocidal concrete are obtained and analyzed, showing a descending branch with an extended section of concrete loading at a constant, decaying strain rate, with a smooth decrease in stress. The concrete deformation diagram on the descending branch is fixed by the ultimate deformation, corresponding to the concrete achieving the maximum strength value, and the end point of the descending branch, corresponding to the residual strength of concrete. The dependences of the influence of the water/cement ratio and the biocidal additive on the main parametric points of the σ–ε diagram are studied. The obtained diagrams are analyzed. It is shown that the introduction of the biocidal additive increases the strength properties of the cement stone. Moreover, the role of the water-cement ratio is revealed: the strength of concrete on a test of normal consistency increased within the range of 12 to 65% (depending on the composition), with an increase in the water-cement ratio these changes are more significant – 29–79%. An increase in the water-cement ratio from 0.267 to 0.350 for compositions with a biocidal additive lead to a decrease in the strength of the cement stone by 27–39%

To effectively utilize reclaimed land and maintain its fertility, it is necessary to ensure the construction and operation of a comprehensive irrigation system (troughs) with a high degree of durability and reliability throughout the entire service life. This research examines issues related to improving the performance of modified heavy-duty concrete operating under harsh conditions. The objective of this study is to establish the feasibility of controlling the grain size distribution of a cement binder modified with a complex modifier (superplasticizer + polymer + microsilica) by forming a spatially reinforced, fine-crystalline structure of the cement matrix with the highest possible packing density, which is maintained over time. The presence of a microsilica component in the complex modifier promotes a pozzolanic reaction with the formation of chemically stable, low-basic calcium hydrosilicates, which positively impacts the corrosion resistance of concrete. Object of study: heavy-duty concrete based on a polydisperse binder with a complex modifier (superplasticizer + polymer + microsilica), reinforced with basalt fiber for irrigation and drainage construction, specifically irrigation system trays. The following research methods were used in the study: laser granulometry, X-ray phase analysis, electron microscopy, and chemical analysis. Mathematical processing of the obtained experimental data was used to form dense packings of finely dispersed fractions of the clinker component. Research results: new data were obtained that complement theoretical understanding of the structure formation process of heavyduty concrete based on a polydisperse binder with a controlled grain size distribution, combined with a complex modifier and reinforced with basalt fiber. A composition and technological solutions have been developed for producing effective heavy concrete for irrigation and drainage construction with improved performance characteristics: compressive strength – 77.3 MPa; tensile strength in bending – 8.62 MPa; water absorption – 1.9%; water resistance grade – W14; frost resistance F1=600, increased resistance to aggressive environments.