The modeling and calculation of the proposed reinforced concrete slab using modern software systems are described. The description of the proposed reinforcement design is given. The results of the experiment on full-scale samples and the results of the calculation of the 3D model are shown. A comparative analysis of the data obtained during the experiment with the data obtained during modeling is performed.

Keywords: reinforcement of building constructions, hollow core slab, Experiment, modeling and calculation, comparative data analysis

The article shows the possibility of reducing the water demand of clinker binders based on gypsum-free cement with a multicomponent additive of technical lignosulfonate and an aqueous solution of sodium silicate. The possibility of obtaining composites based on modified gypsum-free cement with improved properties for building structures has been demonstrated.

Keywords: composite, gypsum-free cement, composition, technical lignosulfonate, concrete, Portland cement, sodium silicate, strength

The article considers the information modeling of the building frame of a complex shape in the plan. The Dynamo program for Autodesk Revit is used to build the geometry. The main goal was to achieve uniform color pressure maps when blowing a building using simulation modeling in an Autodesk CFD PC. The research method is numerical (finite element method). The LIRA-CAD software package was used. The finite element method was used to select the shape of the building and adjust its design scheme to achieve reliability and efficiency. The analysis of the structural elements of the object on the effect of wind loads, taking into account the pulsation component of the wind load, is carried out in order to improve the design decisions made.

Keywords: information modeling, finite element method, building frame, node system, modal analysis, waveforms

The article discusses the existing methods for calculating the strength of a normal section in multilayer bending structures. The experience of Russian and foreign researchers was analyzed, the approaches described in domestic and foreign regulatory documents were compared, and key differences were identified. At the same time, special attention is paid to the mathematical description of the work of concrete as a material. It was concluded that further research is expedient to find the most optimal method for calculating multilayer structures.

Keywords: concrete, reinforced concrete, multilayer structures, calculation method, bending element, normal section, stresses, high-strength concrete, stress diagram, description of concrete work, bending moment, neutral axis

The article is devoted to the development of a nodal joint for assessing the level of rigidity of a cylindrical mesh shell. Practical recommendations on the assembly of the tightening unit are proposed and the design of the screw coupling for the adjustable tension process is presented. The rational locations of the nodal joints on the lower belts of the support faces are determined. Numerical studies of possible schemes were carried out and the regularity of changes in the vertical movements of nodes from the end to the center was established. The positive contribution of reinforcing elements was revealed and the rigidity of the shell was determined. It is shown that the introduction of puffs with a developed node increases the level of resistance to operational loads and significantly reduces deformations in characteristic zones.

Keywords: nodal connection, cylindrical mesh shell, tightening, screw coupling, reinforcement, stiffness

The article discloses the content of geotechnical monitoring, which is an information base for the diagnosis of the condition of the object and the purpose, if necessary, methods for stabilizing the situation, as well as the need for its conduct at linear objects, That is, engineering defences. The analysis of data during the geodetic work on the object «Engineering anti-landslide protection of the northern slope of the Psehako ridge» with the description of the monitoring methodology, which consists of: reconnaissance of the area, development of a network of geodetic points, Taping of the tachemetric passages, taphemeter surveys and subsequent chamber data processing, which results in a report detailing all stages of work and directly concluding that there is or is not deformation. Based on the results of the field measurements, a list of tachemetric strokes, a list of coordinates of the zero cycle were compiled. The tachemetric moves are drawn in the *dwg format at a scale of 1:500.

Keywords: geodetic surveys, geodesy, geotechnical monitoring, desk work, field work, anti-landslide structures

This publication analyzes modern environmental technologies in the field of sustainable construction, discusses the features of the development of modern green construction, current Russian and international trends in the field of sustainable “green” construction, tools for stimulating and supporting projects recognized as meeting sustainability requirements. The importance of integrating environmental aspects into the process of building and managing campuses to create sustainable and healthy environments for the student community.

Keywords: construction, design, operation, ecology, ecological building, energy resource, energy efficiency, energy saving, building sustainability, building certification

A large number of pipelines are designed and constructed using steel pipes. The article analyzes statistical data on the corrosion damage of underground steel gas pipelines. The main failures occur in the areas where the insulation is damaged. During operation, the main focus is on controlling the condition of the pipelines' corrosion protection. In addition, it is important to inspect the pipeline route to analyze the condition of its surface. The analysis of underground gas pipeline damage revealed that the majority of corrosion malfunctions are found in pipelines that are 35–40 years old. Therefore, special attention should be paid to pipes that have been in operation for a long time when managing underground gas pipelines. Operational experience has shown that the majority of faults occur in gas networks with a pipe diameter of 100 mm. Moreover, the article presents an analysis of damage to underground gas pipelines, which found that the greatest amount of damage occurs on pipes laid at a depth of 1.5–1.8 meters. This is due to the increased soil moisture at the specified depth, which contributes to the occurrence of corrosion.

Keywords: operation of underground steel gas pipelines, corrosion damage, protection of underground gas pipelines from corrosion

As a result of artificial carbonization of slag, construction materials can be obtained. For this purpose, a technology has been developed for producing durable construction products as a result of accelerated carbonization of slag minerals with carbon dioxide (CO2) at elevated pressure (up to 2 MPa) and temperatures (20-60°C). The carbonates formed during the carbonization reaction act as a binder, sticking the slag particles together. Carbonized compacts after autoclave processing have technical properties equivalent to conventional concrete products made on the basis of Portland cement. The technology was developed in laboratory and production conditions by optimizing the parameters of the technological process (pressing force, temperature in the autoclave chamber, carbon dioxide pressure in the autoclave chamber and carbonization time) taking into account the increase in compressive strength and frost resistance of the samples.

Keywords: small-sized products, binder, preliminary preparation, steel slag, pressing, accelerated carbonization, minerals, carbon dioxide, strength, frost resistance

The article presents an analysis of modern environmental technologies used in the construction of student campuses. It explores innovative methods and approaches that enable higher education institutions to create sustainable and environmentally friendly campuses. The application of technologies such as energy-efficient buildings, the use of renewable energy sources, waste management systems, green spaces and much more are also considered. The article evaluates the benefits of these technologies, including reduced environmental impacts, economic benefits, and improved quality of life for students. Emphasizes the importance of integrating environmental considerations into campus construction and management to create sustainable and healthy environments for the student community.

Keywords: design, student campus, student dormitory, energy efficiency, landscaping, construction, self-sufficiency, materials, architectural solutions

This article discusses the comparative calculation of solid-stage and three-layer tubular structures with an assessment of the reliability of their application. To do this, their stress-strain state is investigated when exposed to a pulsed load on the wall. Pipeline structures currently occupy important positions in the infrastructures of many countries. Every year new safety requirements are added to the reliability indicators of these structures. Such important strategic facilities fulfill the task of providing people with energy, without which it is difficult to imagine modern life. For a solid-stage pipe, displacements in the nodes of the pipe wall, as well as longitudinal stresses (Nx) and annular stresses (Ny) in the elements of the pipe wall are determined. In a three-layer pipe, the displacements are determined at the nodes of the pipe wall.

Keywords: three-layer tubular structure, solid-walled pipe, load-bearing layer, pulse load, filler, displacement, voltage

Green roofs are of increasing interest as one of the solutions to counteract a number of environmental and socio-economic problems associated with the growth of urban areas. It is necessary to transform the built-up environment by including it in civil engineering, using the existing roof areas of buildings. Eexploitable green roofs need to be integrated into an urbanized urban landscape.

Keywords: sustainable urban development, transformation of urban spaces, green roofs, criteria for the intensity of use of green roofs

The article deals with the improvement of structural solutions of steel reinforced concrete slabs with external reinforcement. The possibility of creating an orthotropic steel reinforced concrete slab on a profiled deck with a continuous or discrete puff located perpendicular to the direction of corrugations is determined. This kind of construction works in bending in two directions along the wave and across the wave. This will allow slabs to be supported on three and four sides, which will make it possible to redistribute the pressure on the supports and reduce the stress concentration at the joints between the slab and the support structure. A continuous puff is assumed to have the same cross-section along its entire length, while a discrete puff can have a variable thickness. Two variants of the calculation of this structure are found, as a monolithic rod with a sprengel chain and as a composite rod with an explicit contact zone. When the stiffness of the contact zone is close to absolute, the rod can be considered as a monolithic rod. An experimental study of the characteristics of the contact zone of the profiled deck organised by means of stamping on the inner side of the corrugation is required, taking into account the perpendicular location of the corrugations to the span of the beam and the concrete part of the section. A comparative analysis of the existing techniques has been made and further experimental investigation methodology has been determined. A numerical evaluation of stresses in a steel plate has been carried out.

Keywords: steel reinforced concrete slabs, orthotropic slabs, calculation methods, contact zone, stamping

The article proposes a new approach to the method of calculating a rigid foundation on a nonlinear and rheology deformable half-space, taking into account the external load variable in time. It is proposed to take into consideration the nonlinearity and rheology of deformation on the basis of modern phenomenological theory using the integral method of successive iterations, which makes it possible to take into account the time-variable mode of external loading, which is characteristic of the stage of construction and operation of structures. An algorithm for the numerical solution of the problem under the conditions of the regime action of external loads using the method of integral estimates based on the step method and successive approximations is presented.

Keywords: rigid foundation, foundation deformation, regime loads, deformation rheology, integral method, phenomenological theory

The article discusses a method for taking into account the compression of concrete using standard formulas when calculating using an inverse numerical-analytical method, taking into account the actual rigidity of concrete filled steel tube elements. The inverse numerical-analytical method makes it possible to calculate concrete filled steel tube elements for strength and stability under eccentric compression. Dependencies are presented showing the possibility of taking compression into account at various eccentricities and flexibility.

Keywords: concrete filled steel tube elements, CFST, inverse numerical analytical method, nonlinear deformation model, concrete compression,concrete filled steel tube column, eccentric compression

Polyethylene pipes are widely used for the construction of gas distribution networks. The disadvantage of pipes is their low mechanical strength. When crossing various artificial obstacles in pipes, unacceptable stresses may arise, causing destruction along the pipe body. To make a decision on the installation of a casing in such areas, it is necessary to determine the stability criteria for the circular cross-section of polyethylene gas pipelines. The article reveals that of the two equations proposed by SP 42-103-2003 for the critical value of external pressure of polyethylene gas pipelines, in practice only one can be used, for which the criterion value is always minimal.

Keywords: polyethylene gas pipelines, dynamic load, stability of the circular cross-section, external pressure

The problem of energy efficiency and rational use of energy resources in housing and utilities sector remains relevant over the past years. In this regard, the reduction of heating and hot water costs remains under continuous review of specialists all over the world. The article discusses the issues of using low potential thermal energy of domestic wastewater for hot water heating. Data on wastewater temperature in various locations are presented. The main designs of wastewater heat recovery units and the features of their application are considered. It is shown that the temperature parameters of residential building wastewaters differ significantly and depend not only on the climatic zone, but also on the regional features of water consumption. It is concluded that in process of wastewater heat recovery it is possible to reduce wastewater temperature at least by 5 ºС, and in hot season ‒ by 10-15 ºС. The analysis of literature data lead to the conclusion that wastewater heat recovery units are more promising and viable at building level as well as sewer or wastewater treatment plant level. For these cases, greater efficiency can be reached by using heat recovery facilities with a heat pumps.

Keywords: hot water supply, sewage, low potential heat, wastewater temperature, heat pump, heat exchanger, waste water heat recovery, energy saving

Welding is the main method of joining plate steel. Its use leads to significant residual welding stresses. Residual stress can significantly affect the load-bearing capacity of long-span steel bridges. In this work, a finite element calculation of residual welding stresses of steel sheets up to 100 mm thick was carried out, and the distribution of surface residual stresses and the influence of sheet thickness on the residual surface stress were identified.

Keywords: steel bridge, plate steel, welding residual stresses, finite element method, welded joint, stress distribution

The results of numerical modeling of wooden beams strengthened of composite materials based on carbon fiber are considered. Modeling of beams strengthened of composite material was carried out in the ANSYS software using deformation diagrams. The reliability of the modeling methodology was assessed by comparing the results of a numerical study with the results of a physical experiment obtained during testing of models of wooden beams strengthened of composite materials based on carbon fiber.

Keywords: carbon fiber, carbon composite materials, strengthening of wooden structures, external reinforcement of wooden beams

The article raises the problems of preserving historical architectural and natural complexes on the example of the Peter and Paul Park in Yaroslavl. In the Introduction to the article, attention is drawn to the importance of the problem of preserving historical monuments of architecture or art not only in the capital cities, but also on the periphery. The following are the main methods used in the work to assess the state of the architectural and park ensemble, to identify its characteristic architectural and landscape features and to develop a theoretical conservation model. In the main part of the article, the historical stages of the formation of the architectural and park ensemble of the Peter and Paul Park, their influence on the final appearance of the ensemble are considered; a comparative analysis with similar architectural and park ensembles is given, common characteristic features are identified and the principles of the formation of the Peter and Paul Park are established. As a result of the conducted research, a model of preservation of the Petropavlovsk architectural and park ensemble of Yaroslavl is proposed, presented in the form of a master plan of the park territory, which contains proposals for the reorganization of the territory, pedestrian park network and restoration of historically significant structures. In the final part of the article, the main conclusions based on the results of the study are formulated.

Keywords: architectural and park ensemble, Peter and Paul Park, Yaroslavl Big Manufactory, regular layout, theoretical model of conservation

High-rise buildings with CLT (cross-laminated timber) load bearing structures are being more actively developed in many countries. CLT-panels are lightweight, ecological and easy to assemble. In the article types of strengthening of three-layers and five-layers CLT-panels with carbon, basalt and flax fiber reinforced polymers (FRP) are considered. They can be used for panels under exploitation to reduce influence of defects and increase load bearing capacity and stiffness or in the production stage to reduce thickness and weigth of constructions. Known works of international authors are analyzed. Bending behaviour of externally reinforced CLT-panels is described. Areas that deserve further investigation are determined. They include investigation of different composite materials and wood types used for CLT-panels' production.

Keywords: CLT, composite, cross-laminated timber, external strengthening, FRP, high-rise building, lamella, reinforcement, timber structure, wood

The Russian Federation is a multi-religious state, which has recently seen an increase in the construction of various religious buildings. At the same time, the bulk of the churches being built are small buildings, located, as a rule, in villages and small towns and designed for simultaneous visits by up to 120-150 parishioners. Various materials are used for their construction, including wood. Usually these are log or block buildings, but it is also possible to use other wooden housing construction systems, including light frame ones. The theoretically possible remoteness of towns and villages from large district and regional centers, the impossibility of delivering large-sized beams and logs, the lack of their own production base and other factors lead to the need to use ordinary boards in wooden frame structures. As an example, we consider the construction of the Church of the Transfiguration of the Lord in one of the farms in the Rostov region, the load-bearing structures of which are made using light-frame house-building technology. The presence of open space in the central part of the Temple and the placement of an octagon-shaped superstructure above it required the use of a supporting structure made of steel I-beams. Thus, the structure of the Temple frame is a metal-wood system. The article shows that the combined use of steel and wood in light-frame buildings ensures a rational organization of the space of religious buildings.

Keywords: religious building, temple, belfry, octagon, narthex, altar, wood, light frame building, beam, I-beam, supporting structure

The influence of blast furnace ground granulated slag on the kinetics of strength gain of concrete prepared with a composite binder was revealed. The composite binder contained Portland cement in amounts of 70, 60 and 50%, and the rest was ground granulated slag. It has been established that at the early stage of strength development, concretes made with a composite binder have a strength lower than concrete prepared with Portland cement by 10-24%. However, at the age of 28 days, the strength of concrete using a composite binder corresponds to the strength of concrete using Portland cement. Using polycorboxylate hyperplasticizers, it was possible to obtain concrete with a W/C ratio of 0.25-0.35, which made it possible to obtain high early strength exceeding control compositions by 10-20%.

Keywords: portland cement, grn slag, grinding, composite binder, kinetics of strength gain, hyperplasticizer, kinetics of strength gain

The world's reserves of renewable energy sources are steadily declining, but the comfort of life in modern society should remain at the same level. The modern solution of the problems of thermal protection of facade systems of buildings is associated with the analysis of the specific heat capacity of the materials included in their composition. The use of new energy-efficient materials is becoming especially relevant. Such materials include vacuum thermal insulation panels, which significantly reduce heat loss in comparison with traditional thermal insulation.

Keywords: energy efficiency of buildings, thermal protection of facade systems, thermal insulation, vacuum thermal insulation panels, construction production

The article presents the results of a survey of two industrial buildings, conclusions about their emergency technical condition and the inexpediency of restoration. Modern methods of demolition and dismantling of buildings in the cramped conditions of the existing urban development are analyzed. The main technologies of recycling dismantling and disposal of construction waste generated during the dismantling of buildings are considered: "smart demolition" and the technology of piecemeal disassembly of buildings with the reuse of materials, products and structures. Comparing the two methods of recycling dismantling for application to the objects under consideration, it is concluded that the first method of "smart demolition" implies the destruction of all building structures, while the second is more rational in terms of resource conservation and economic efficiency by reuse of serviceable structures. The technology of piecemeal disassembly of buildings with the reuse of structures requires the development of regulatory, organizational and marketing measures.

Keywords: building inspection, demolition, dismantling, dismantling methods, smart demolition, recycling dismantling, reuse of structures