The authors developed a model for single reinforced concrete strips in block wedge and arches between inclined cracks and approximated rectangular cross-sections using small squares in matrix elements. From the analysis of the works of N.I. Karpenko and S.N. Karpenko the "nagel" Qs forces in the longitudinal tensile reinforcement and crack slip D _s , as a function of the opening width and concrete deformations in relation to the cosine of the angle q . The experimental " nagel " forces Q_s,exp and crack slip D_crc,exp dependences for the connection between D_crc,exp and 0 а h/₀ in the form of an exponent for the reinforcement deformations e _s × m_s,3 and spacing 1_x are determined. The forces have been calculated for two to three cross-sections (single composite strips) of reinforced concrete structures.

On the bases of accepted hypothesis, a new effect of reinforced concrete and a joint modulus x_m in a strip of composite single local shear zone for the difference of mean relative linear and angular deformations g_{zx,stitch,sum,i} of mutual displacements of concrete (or reinforcement) are developed. The hypothesis allows one to reduce the order of the system of differential equations of Rzhanitsyn and to obtain in each joint the total angular deformations of concrete and the "nagel" effect of reinforcement. The curvature of the composite bars has a relationship from the total bending moment of the bars to the sum of the rigidities. The stiffness physical characteristics of the matrix from the compressed concrete area and the working reinforcement are obtained in a system of equations of equilibrium and deformation, as well as physical equations.

This paper considers elastic isotropic plates in the form of isosceles triangles with combined boundary conditions (a combination of hinged support and rigid restraint conditions along the sides of the contour). Calculations were performed using FEM to determine the integral physical characteristics in the considered problems F (the maximum deflection of uniformly loaded plates w0 and the fundamental frequency of oscillations in the unloaded state ω). On the basis of the obtained numerical results, approximating functions have been constructed: "maximum deflection - form factor of plates", "basic frequency of oscillations - form factor of plates", the structure of which corresponds to the structure of similar formulas obtained when presenting known exact solutions in the corresponding problems of technical theory of plates in isoperimetric form. Based on the properties of the form factor of plates, these approximating functions limit the whole set of considered integral physical quantities and therefore can be used as reference solutions for the calculation of triangular plates of arbitrary form applying the method of interpolation by form factor (MIFF). We consider an example of calculation of a plate in the form of a rectangular triangle with hinged support of the sides.

There were a number of characteristic damages and defects in typical panel houses when examine, one of which are tilts and biases of wall panels. The stiffness of the wall panel with the opening of residential building I-515/5 series has been determined at a given bias in its plane. The panel was calculated numerically using a nonlinear deformation model by the finite element method and analytically. The software package, LIRA-SAPR 2017, was used in this investigation. The calculation was carried out taking into account the nonlinearity and material creep. As a result, the fields of normal and shear stresses in the panel were obtained and the shear rigidity was calculated. The analysis of the obtained results showed that a possible decrease of the actual stiffness of the panel should take into account against the calculated stiffness was obtained according to the standards.

The relationship between the maximum deflections from a static uniformly distributed load W0 and the fundamental frequency of natural transverse vibrations of a round isotropic plate of linearly variable thickness with thickening to the edge under homogeneous conditions of support along the outer contour, depending on the ratio of the thickness of the plate in the center to the thickness along the edge, is considered. According to the results of the study, graphs of the dependence of the maximum deflection and the frequency of natural vibrations of the plate on the ratio t₁ / t₂ are constructed. It is shown that for round plates of linearly variable thickness at t₁/t₂<1.1 coefficient K with an accuracy of 5.9% coincides with the analytical coefficient for round plates of constant thickness. Numerical studies shows that when the ratio of the thicknesses on the contour and in the center is equal to two, the difference in the coefficient K, which depends on the relationship between the static and dynamic characteristics of the platinum, is about 25% for hinged support along the contour and up to 37% for rigid support. This indicates a more significant effect of uneven mass distribution for such boundary conditions. >< 1.1 coefficient K with an accuracy of 5.9% coincides with the analytical coefficient for round plates of constant thickness. Numerical studies shows that when the ratio of the thicknesses on the contour and in the center is equal to two, the difference in the coefficient K, which depends on the relationship between the static and dynamic characteristics of the platinum, is about 25% for hinged support along the contour and up to 37% for rigid support. This indicates a more significant effect of uneven mass distribution for such boundary conditions.

The heat and humidity regime of the buried parts can be essential, and sometimes crucial, for the normalization of the microclimate of the entire monument. The experience of thermophysical studies in church architectural monuments shows a wide range of factors that determine the impact of the temperature and humidity regime of the buried volumes on the formation of conditions for the preservation of the monument as a whole. Currently, the Climate Laboratory of Museums and Architectural Monuments of GOSNIIR conducts research on this problem in order to create a methodology for studying and normalizing the heat and humidity regime of the aboveground and underground parts of the building as a whole to develop design and technological approaches to optimizing the conditions for the preservation of the monument. The article considers a practical example of providing heat and humidity conditions for the preservation of a monument with monumental painting.

The Russian standardsfor earthquake resistant constructions suppose the development of plastic strains in reinforced concrete constructions under seismic effects. Their presence influences significantly on the stress-strain state, bearing capacity and mechanism of destruction of reinforced concrete constructions under alternation loads of high intensity. The methodology and main results of experimental tests connected with the evaluation of plastic deformations influence on the behavior of reinforced concrete bending elements when changing the force sign is represented. The information about the bearing capacity reduction when changing the force sign with the increase of plastic strains in the first semi cycle of loading is given. The coefficients of plasticity for reinforcement deformations limit values are obtained, corresponding to the beginning of compressed zone concrete destruction when changing the force sign and the plots of normal sections deformations distribution of experimental specimens under direct and reverse loading have been built.

After a period of relative calm in the construction and design of thin-walled largespan shells and network multilayer shell structures, which, according to the world's leading architects, began in the 1980 s, the time has come for the expanded use of spatial structures in the architecture of public and industrial buildings. Less commonly, shells are used in small-sized housing construction: ecological villages, noospheric and bionic architecture. The entire 20th century did not stop research on the development of analytical and numerical methods for analyzing shells for strength and stability, for the creation of new building materials. Geometers have created and studied more than 600 analytical surfaces that can be mistaken for the mid-surfaces of civil and mechanical engineering shells. As a result, by the beginning of the 21st century, architects and engineers had all the necessary tools to continue the traditions of the "golden age of shells". The analysis of problems with the use of new forms in parametric architecture, carried out in the article, showed that more than ten classes of surfaces from their classification have not yet found application in architecture and mechanical engineering. It is assumed that the number of applied classes of surfaces will not expand, and new ideas for the shaping of shells will be based on the use of already well-known surfaces, namely, surfaces of revolution, transfer, umbrella, minimal, ruled and wavy surfaces. Mainly, shell structures will be designed taking into account environmental, energy-saving requirements and transforming structures.

Variants of architectural, spatial, and compositional solutions of entrance signs in small towns are considered. The article analyzes the features of architectural and artistic, structural, and compositional solutions of the entrance sign, as well as the use of finishing materials.

The urgency of development of small cities taking into account the historical, cultural, economic characteristics and achievements of the district, as well as symbols of culture and long history of the region in the context of solving problems of urban development.

The requirements for the assessment of each characteristic indicator that affects the identification of new architectural, artistic and aesthetic possibilities for the representation of the symbol at the entrance to a small city are given.

In the Russian Federation, most low-melting clays used in the production of ceramic bricks have a low content of aluminum oxide (Al₂O₃=12-15%). With such a low content of aluminum oxide in clay materials, it is impossible to obtain bricks of grades M150 and higher from them. For the construction of load-bearing walls of the lower floors of high-rise buildings (15 floors or more), ceramic bricks of the M150-M300 brands are required. In such clay materials, to obtain earthquakeresistant bricks M150 and higher, it is necessary to introduce a thinning agent containing A1₂O₃>50%. Taking into account the reduction of reserves of traditional high-alumina natural raw materials, it is necessary to find new ways to replace it with various types of waste. The experience of advanced foreign countries has shown the technical feasibility of this direction and its application as a tool for protecting the natural environment from pollution. In this paper, instead of natural traditional desiccants, it is proposed to use slag from the smelting of carbon-free ferrochrome containing A1₂O₃=55.8%. As a clay material, substandard beidellite clay was used, which is not suitable for the production of ceramic bricks without thinners. A ceramic earthquake-resistant brick M125-M175 was obtained on the basis of slag from the smelting of carbon-free ferrochrome and substandard clay in the temperature range of 1050-1100^oC

The article discusses the option of strengthening the soils of the roadbed of highways with complex binders based on granular slag of copper smelting production and air lime. The characteristics of the investigated slag, photomicrographs of its surface, as well as the chemical and phase compositions are presented. A detailed description of the X-ray diffractogram of the studied slag with the processing of the obtained reflections using the ICDD PDF-2 database is presented. Calculations of hydrolytic equilibria were carried out using the main phases found from the data of Xray phase analysis. It was found by the calculation method that at pH = 11-12 in the lime-slag mixture decomposition of iron silicates and aluminosilicates occurs with the formation of gels of iron and aluminum hydroxides, as well as amorphous silica. On the basis of the obtained complex binder, standard samples of strengthened soil based on loam were made and tested to determine the physical and mechanical properties. The results of the experiments carried out create an opportunity for obtaining hardened soils based on a complex mineral binder with a compressive strength of up to 2.2 MPa.