The article provides information about the tests of rectangular cross-section reinforced concrete beams made of high-strength steel-fiber concrete on combined torsion and bending. Given information contains the main results: a diagram of the cracks with an indication of their opening width, the values of support reactions at the moment of cracking and at the moment before destruction. It was found that as the load is applied in beams made of high-strength steel-reinforced concrete, in the case of several cracks at the first stage, there is one crack increases. The beams are modeled in the design complex and given description of the main design parameters. The results of the calculation are presented and a comparative analysis of the results obtained with the experiments results. It is noted that the adopted models in the computational complexes require the development of subroutines and refinement.

On the basis of the carried out experimental and numerical studies, the mechanism of crack formation in the masonry of the face layer with flexible ties under temperature influences has been established. Experimental studies were carried out for five years on a floor-high fragment of a building formed by external three-layer walls resting on a monolithic reinforced concrete slab. Numerical studies were carried out using the author's specialized program for calculating masonry structures, which implements the finite element method, taking into account structural nonlinearity. The program was verified by comparing the calculation results with the experimental data, as well as at the stage before the formation of cracks using the LIRA-SAPR program. It is shown that, depending on the ratio of the tensile strength of the masonry along the vertical joints and the cut along the horizontal mortar joints, different variants of crack development are possible. Vertical cracks, like expansion joints, reduce tensile and shear stresses. Cutting the masonry along the horizontal mortar joint at the base of the wall leads to a reduction in the length of the area of influence of the floor slab. Together, this leads to a decrease in the level of tensile and tangential stresses and damping of the crack propagation process. At the top of the wall, the effect of the floor slab on the stress-strain state of the masonry is relatively small and the temperature deformations there are close to free. This made it possible to apply a simplified methodology for assessing the crack opening width. A method is proposed for calculating the facing layer masonry for temperature effects and for assigning distances between vertical expansion joints.

One of the most important issues when calculating buildings and structures for seismic effects is taking into account the presence of damage in the compressed zone of concrete. It is known that the current norms of the Russian Federation [4] on earthquake-resistant construction assume the development of plastic deformations in structural elements. When determining the loads, the possibility of developing plastic deformations in structural elements is taken into account by introducing a decreasing coefficient K1, while neglecting the effect of plastic deformations on the strength of bearing reinforced concrete elements. The presence of plastic deformations in the reinforcement leads to the appearance of residual cracks in the compressed zone of concrete and, as a consequence, to a decrease in the bearing capacity of bending elements in subsequent loading cycles. The influence of unclosed cracks in compressed zone of concrete of bending elements on their bearing capacity for symmetrical and non-symmetrical reinforcement, for different values of reinforcement coefficient and for different values of coefficient of plasticity is considered. Based on the results of calculations the bearing capacity data for bending reinforced concrete elements with residual cracks in compressed zone of concrete have been obtained. The approximate method of determination of residual cracks depth in compressed zone of concrete in terms of coefficient of plasticity in the first semi cycle of loading is proposed.

In this paper, resistance the shear lintels in multi-story buildings is considered, since the main static purpose of vertical butt joints in the form of lintels is to ensure the perception of shear forces arising from the joint operation of the mating walls. The object of the study was a fragment of a monolithic building, the thickness of the walls of which was 300 mm, and the height of the building was 12 floors. As a result of the conducted numerical studies, the stress-strain state of the vertical load-bearing structures of monolithic buildings and the shear deformations along all the lintels along the height of the building were determined. It was found that some of the lintels are in the elastic stage of operation due to a low level of shearing forces. A number of building lintels connecting vertical structures with a significant vertical load drop are in the plastic stage of work. The results of stress redistribution, given in this article, can be used when calculating the bearing systems of monolithic buildings, taking into account the nonlinear compliance of shear bonds.

The calculation of the resistance of piles in the foundation is proposed according to an extended scheme, which includes the surrounding soil, which is inextricably connected with the pile through the side surface. The implementation of the extended scheme is possible with the application of the method of testing a model pile with a constantly increasing load with continuous measurement of precipitation (CRL method), supplemented by measurements of soil deformations relative to the pile surface and displacements of deep marks near the pile. Increasing the amount of information about the state of the soil allows us to obtain the values of additional forces elastically transmitted to neighboring piles, depending on the size of the areas of plastic deformation of the soil. The assessment of the mutual influence of piles during the increase in load on the foundation makes it possible to choose the best option of its parameters, including the size of piles, their placement in the foundation, changes in resistance and settlement over time.

The article presents a method for determining the stresses arising in the protective layer of concrete in the presence of a porous zone around the "steel-concrete" interphase medium. It has been shown that radial cracks form and propagate in the concrete surrounding the reinforcement until the ultimate serviceability state, such as chipping or delamination of concrete, occurs. The generated hoop tensile stresses in concrete strongly depend on the ratio of the volume of a unit mass of rust to the volume of iron. Calculated formulas for the pressure applied by corrosion products to the concrete layer are given.

This paper considers a territory that has cultural, archaeological and natural conservation regulations for its use. The problems of preservation and functional relevance of cultural heritage objects, as well as attracting the scientific community for research and further museification of archaeological monuments are raised. The article examines a park in the city of Semiluki, Voronezh region with objects of natural and cultural heritage, its role for city residents. The possibilities of using such territories have been studied in compliance with protective regulations. A methodology has been developed for preserving the historical landscape and soil cover by creating a new multifunctional public space and designing non-stationary structures. The paper put forward proposals for the further development of such territories while preserving their uniqueness.

The main legislative acts and normative documents in the field of comfortable and safe urban environment are considered. The analysis of the requirements of technical regulation contained in the current legal and regulatory documents in the Russian Federation to ensure safety and create comfortable living conditions is presented. The conducted analysis showed the urgent need to build a new conceptual model and the calculation justification of new normalized parameters in the subject area of a comfortable and safe living environment of the city. The analysis also revealed the need to improve the methodology for assessing the state of the urban environment, for example, from the point of view of symbiotic integration of the city into the natural environment and creating conditions for human development. The methodological basis of the study was the paradigm of life activity - biosphere-compatible cities and settlements that develop people. Based on the principles of the biosphere compatibility paradigm, a systematization and ordering of the variety of existing regulatory documents was carried out, thereby identifying certain issues of rationing, for example, the level of comfort of the urban environment, which today are not regulated by the regulatory framework, but are acute and actively discussed by the professional community. The results of the research can be used in the development of the set of rules " Comfortable and safe living environment of the city. Basic provisions".

The article presents the effect of additives and water on the compressive strength and flexural strength of foam concrete after 28 days of normal hardening. The foam concrete mechanical properties are determined according to the GOST 10180-2012. The initial composition of the foam concrete mixture was calculated by the absolute volume method. As a result, the first-order regression equations are obtained. The compressive strength and flexural strength of foam concrete depended on the ratios x₁ (В/(Ц+ДШ) and x₃ (МК90/Ц), as well as on the expression of the image surface and the objective function for the regression equations. The optimal value was obtained: compressive strength = 42.14 MPa and flexural strength of 6.31 MPa.

The high cost of ceramic pigments contributes to the expansion of research on their replacement with large-tonnage industrial waste. Charge compositions based on low-quality clay raw materials with additions of wollastonite with a dispersion of 10 microns (OOO Tekhnokhim, Novosibirsk) and waste of ferrosilicomanganese deposited in bag filters (West Siberian electrometallurgical plant, Novokuznetsk) were tested. It was found that the introduction of 9 wt. % wollastonite and 5 wt. % waste in semi-dry pressing leads to a content of 15 wt. % wollastonite - 2M with a maximum specimen strength of 45.5 MPa and water absorption of 14 wt. %. Refusal to use the addition of wollastonite with an increase in the dosage of the waste to 10 wt. % made it possible to reduce water absorption to 11.5 wt.% without loss of strength. The color of the che-turnip is dark chocolate.

The main task of the implementation of environmental policy is to create a resource-efficient system for the placement and disposal of industrial waste and secondary raw materials, in particular, in the production of building materials and products of specified properties. Within the framework of these studies, issues related to the activation of microsilica, which is a waste of ferroalloy production, and methods of its use for modifying the structure of cement stone, in particular, for heavy concrete, are considered. The mechanism of the structure formation process, the method of introduction and the optimal consumption of the additive for modifying the concrete mixture have been determined. With the help of a comprehensive study, the products of dispersion of microsilica, which is part of the complex modifier, have been determined. It has been established that the process of the chemical activation of mineral particles has not been sufficiently studied, in this regard, the presented studies, which consist in finding solutions to increase the operational characteristics due to the process of pretreatment of microsilica with an alkaline medium pH = 10.2 together with a micro-reinforcing component, are relevant. The aim of the study is to establish the positive effect of the activation process of silica fume together with a micro-reinforcing component on the modification of the structure of heavy concrete to increase the hydrophysical properties. The object of research is a modified heavy concrete based on activated microsilica with a micro-reinforcing component. In this work, the following research methods were used: physicochemical activation of microsilica with water, treated by electrolysis with the Melesta device; determination of the frost resistance grade in the WK3 180/40 climatic chamber; water tightness was determined in the UVB-MG4.01 installation; water absorption was determined using a SNOL electric digital oven. Research results: a positive effect on the hydrophysical properties of heavy concrete was established by reducing the content of the binder (cement) and replacing it with a microdispersed filler previously activated with an alkaline medium with pH = 10.2. Further modification with a complex additive (high-water-reducing additive "MasterGlenium 115" with a consumption of 1% plus a reaction-chemical additive with microsilica grade MKU-95 - 15% of the binder mass) together with basalt fiber, improves the following characteristics: water absorption - 2%; waterproof grade - W14; frost resistance - F600, which makes it possible to apply this composition in practice to obtain building products and structures with specified characteristics in harsh operating conditions.