An analysis of known methods for evaluation the compressive strength and modulus of elasticity of existing masonry structures have been carried out. A method for determining the mechanical characteristics of masonry, based on tests of the specimens cutted from the body of the masonry in the form of triangular prisms have been given. Comparison of compressive strength, initial shear strength and angle of internal friction, obtained from the results of tests of prism specimens, with the results of tests of masonry specimens in accordance with the standards STB EN 1052-1 and STB EN 1052-3 has been carried out. Satisfactory agreement between the values of the compressive strength of the masonry and the secant modulus of elasticity obtained by testing the prisms with a compressive load acting perpendicular to the plane of the horizontal mortar joints with the test results according to the STB EN 1052-1 method has been shown. The initial shear strength of masonry, obtained from the results of tests according to STB EN 1052-3, differed downward from the strength established from the results of tests of prism specimens for compression, while the values of the angle of internal friction determined by the two methods were close.

The analysis of the types of damage to vertical load-bearing elements of masonry from explosive impacts is carried out, the main signs of such damage requiring special reinforcement methods are described. Modern methods of restoring the bearing capacity of masonry require refinement and adaptation when considering cases of explosive impacts. A substantive examination of the load-bearing walls revealed a decrease in the adhesion forces between the brick and mortar, degradation of the connections between the outer verst and the main masonry array. To restore the bearing capacity of damaged elements, a modern method is proposed, consisting in the device of one-sided applications of shotcrete, which allows to restore the destroyed connections inside the masonry and provides a high level of mechanization of labor. Experimental studies were conducted to determine the physical and mechanical characteristics of shotcrete, as well as the adhesive strength between the concrete of the application and the masonry brick, which ensures the compatibility of the reinforcement structure of shotcrete and existing masonry. Tests were carried out on 20 samples with a ceramic brick base to determine the physical and mechanical characteristics, prisms and cylinders made of shotcrete were tested. It is determined that the technology of applying shotcrete at a speed of 150 m / s leads to a decrease in the specific weight of the mixture due to its compaction. It is established that with the same modulus of elasticity of shotcrete and heavy concrete, the prismatic strength of shotcrete is significantly greater. According to the research results, the modulus of elasticity of shotcrete is 26400 MPa, the average prismatic strength of shotcrete is 42 MPa. The obtained characteristics can be used for numerical modeling and computational justification when developing a structural reinforcement project.

The paper provides a physical and computational model for determining the parameters of limit states of reinforced concrete structures under complex stress state such as bending with effect of axial and shear forces. The forward and backward transitions for determining the stiffness matrix coefficients of reinforced concrete bar structures with inclined and normal cracks have been constructed on the basis of the adopted cross-section discretization scheme and the duality theorem between force and deformation parameters by A.R. Rzhanitsyn. Determination of the stiffness of structures in the zone of inclined cracks was performed on the basis of the model of composite strips into which the zone with inclined cracks is divided. It is assumed a hypothesis about the character of deformation distribution in a complexly stressed reinforced concrete element with inclined cracks. For this model the effective shear modulus has been obtained. It 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. Using this model and the experimentally obtained value of the relative shear in the inclined crack, the dowel forces in the reinforcing bar crossed by the inclined crack were determined. The use of the obtained analytical dependences in the practice of designing reinforced concrete structures allows to clarify significantly the definition of displacements and width of opening of inclined and normal cracks, as well as to bring the calculation and physical model based on experimental data as close as possible.

Under the action of horizontal wind and seismic loads, torsion occurs in asymmetric load-bearing systems of multi-storey buildings. The reason for torsion is the appearance of an eccentricity between the center of mass and the center of rigidity of the application of a horizontal load. Vertical loadbearing elements of panel buildings are connected into a spatial system by various shear bonds. The deformability of welded butt joints in a nonlinear formulation is based on experimental data on the action of shear forces. Considering that the deformability of a shear connection depends not only on the shear force, but is also a function of all forces and stresses along the height of a multi-story building, a complete deformation diagram of the shear connections under consideration is necessary. The influence of torsional action on the deformability of shear bonds has not been previously considered. This paper presents a finite element model realized in the ANSYS software package of a fragment of a panel building. The building fragment was determined under the condition of further experimental studies on the strength and deformability of the welded joint connecting two vertical load-bearing structures.

Numerical simulation determined the stress-strain state of a vertical dense joint of panel buildings under the action of shear and torsion. Step loading of the investigated fragment was carried out in the vertical and horizontal plane. The loading history adopted in the first approximation is the simplest – proportional. The bearing capacity and deformability of the joint under the action of shear and torsion are determined. Diagrams of the deformation of a dense joint are obtained. The ultimate load at which the joint becomes a hinge is determined. The torsional effect leads to an increase in the deformability of the dense bond. The results of the analysis can be used in the diagrammatic method of calculation of reinforced concrete structures of panel buildings subject to torsion.

External reinforcement of reinforced concrete structures with composite materials is successfully used for strengthening of damaged elements. At the same time, torsion with bending of such reinforced concrete structures is poorly studied and requires experimental and theoretical investigation. The scientific literature presents the results of the study of strength and deformability in bending with torsion of reinforced concrete elements of different cross-sectional shapes under static and dynamic loads, elements of composite cross-section. For reinforced concrete structures strengthened with external reinforcement by composite materials, such studies were carried out only for bending elements. The authors have developed a program and methodology of experimental studies of such structures. The results of experimental investigations according to the proposed methodology will allow us to verify the assumed design model, the working assumptions put in its basis and reveal the regularities of deformation of reinforced concrete structures with external composite reinforcement under bending with torsion.

The numerical study focuses on analyzing the structural response of reinforced concrete (RC) beams at high temperatures. Gaining more insight into the behavior of reinforced concrete (RC) structures at high temperatures and the material properties of steel reinforcement and concrete are the main goals of this research. To conduct this analysis, finite element analysis (FEA) using the ABAQUS software package is adopted. FEA allows for the simulation of the behavior of the RC beam under fire by inputting relevant parameters, such as material properties, dimensions, and temperature. The program calculates the temperature distribution within the structure and predicts the resulting structural responses. Two phases are applied: before and after exposure to fire. Both normalstrength concrete (NSC) beams and high-strength concrete (HSC) beams are considered. The results indicate that high temperatures have a detrimental effect on the overall behavior of concrete beams. At 600°C, the residual strength of HSC beams is shown to be twice that of NSC beams

The relevance of the study is due to the fact that erosion of the surface of building materials is a common phenomenon observed on the facades of historic buildings. Climatic changes can lead to an increase in the frequency and intensity of extreme precipitation, which can increase the erosion effects on the facades of buildings due to the wind-driven rain. The purpose of the study is to compare experimental methods for assessing the degree of surface erosion of historic building materials under the influence of wind-driven rainfall. The objectives of the study are to review modern methods for measuring the effect of rain with wind on the surface erosion and reduction of the strength of brick and limestone; to critically analyze the best-known methods for assessing the degree of erosion of the surface of building materials; to offer recommendations for the protection and restoration of damaged facades of cultural heritage objects due to the wind-driven rain. The significance of the obtained results for architects and designers is that the use of methods to assess the degree of damage to the facades of architectural monuments due to wind-driven rainfall makes it possible to monitor and develop measures to protect objects of cultural heritage.

The purpose of the study is to consider the classical model of the analysis of an architectural object, which is a trinity of traditional (universal), professional (modern) and general scientific research methods (methods of related sciences). Traditional research methods include the analysis and interpretation of historical research, archival documents, manuscripts and other sources. Professional methods include examination, engineering analyses and research using modern technologies. General scientific research methods include the use of knowledge from various scientific disciplines, such as history, archaeology, architectural theory and practice, sociology, psychology, and others. The process of formation of classical analytical methods for studying architectural objects took place within the framework of ancient philosophy and aesthetics. formation and development of the analysis methodology. Structural analysis involves the consideration of the scientific method as a system of its constituent elements and the principles of interaction of these elements, the study of their interrelationships. The application of this approach in the study of the scientific method is justified by the complexity of its organization. Attention is paid to the analysis of aspects of the perception of architectural monuments. The structure of the method of historical and architectural research allows us to show the theoretical foundations of a special research method that establishes a link between the categories of general and particular in the methodology of architectural monuments, analyze historical and architectural data in the context of their general significance and specific features. In conclusion, the article emphasizes the importance of analyzing historical and architectural objects for the preservation of historical heritage and cultural value of buildings. 

The article discusses the problems of improving the quality of the living environment in the special conditions of Palestine, as well as the theoretical foundations of programs (vectors) for the transformation of residential areas in the formation of an architectural and landscape complex based on a model of complex schemes of the environment-regulating system. Natural characteristics and human activity are the main elements of this system since their interaction is a condition for transformation in accordance with the principles of architectural and urban planning organization of residential development while maintaining the similarity, integrity, and effectiveness of interactions based on the principles of mutual influence and interdependence of old and new. Cases of contradictions and differences are identified on the basis of a comprehensive assessment of the development site in planning, functional, and compositional aspects, according to the principles of interaction between old and new. At the same time, it is determined how the formed elements of the environment as a result of human activity function under the influence of natural characteristics. As a result, areas of internal discomfort are identified. Development of a program of targeted transformations of the characteristics of the residential urban environment based on a step-by-step analysis of the interaction of the main elements of the system, the ultimate goal of which is to improve the quality of urban space. Identification of the environment-forming potential of the territory determines a method of measures in accordance with climatic, aesthetic, and environmental changes in the metropolitan area. Based on the principles of architectural and urban planning of comfortable residential areas, according to the principle of value and the direction of analogy, the environmentforming potential of the territory is determined. This is done by analyzing the mutual influence of natural characteristics and human activities. In conclusion, based on the study, trends are identified to improve the development and comfort of products located in accordance with accepted priorities and specific requirements.

The definitions of concepts “Architectural style”, “Architectural direction”, and “Style flow” are given. Five architectural groups that are “Vanguard”, “Ar-deco”, “Modernism”, “Eco-tech”, and “the Newest Styles” containing erections of curvilinear form, shell structures, and thin shells of building purposes were determined. In the work, all known architectural styles and their subsemblances as applied only to erections of curvilinear form including shell structures and thin-walled shells were firstly gathered and illustrated for concrete examples. The known definitions for architectural styles, directions, and style flows that reflect exactly the content of these concepts are presented. The proper chronology of origin of architectural styles and their sub-semblances are adduced. Marked rise of interest to designing and building of large-span shells and shell structures in the 21st century is mentioned. In the 21st century, architects used 16 architectural styles. The materials presented can help to the researchers in the carrying of new investigations devoted to classification of architectural styles, their systematization, more accurate definition and chronology of their appearance.

The article presents the results of the effect of the additive on water resistance, frost resistance and workability, which are one of the main indicators of the physical and mechanical properties of concrete. In the presented work the authors used a complex additive containing alkali (caustic soda), post-alcohol bard and hardening regulator (gypsum) in different % ratios. It is shown that the use of a complex additive in the composition of concrete significantly increases the water resistance and frost resistance compared with the control samples. The influence of the complex additive on the workability of concrete mixture has been studied. It has been established that the complex additive allows obtaining highly workable concrete mixtures and reducing their water separation, providing high preservation of concrete mixtures. The water impermeability of concrete is also significantly improved - the water impermeability grade increases by 4 steps in comparison with the concrete without additive. The proposed method speeds up the process of determining the concrete water impermeability grade and allows you to determine the water resistance grade and the degree of permeability of concrete on the basis of the obtained dependencies. When adding a complex additive in an amount of up to 7 % of the weight of cement increases the brand on frost resistance. It is found that the concrete with the studied complex additive has high physical and mechanical properties. The optimum dosages of the considered additive were found and used in the present work.