Geopolymers and alkali-activated materials are cement-free composites formulated by activating alumino-silicate materials, such as fly ash, meta-kaolin, and silica fume, and calcium-rich materials. The Geopolymer Materials Market grew from USD 12.48 billion in 2023 to USD 15.69 billion in 2024. It is expected to continue growing at a CAGR of 29.46%, reaching USD 76.07 billion by 2030. Today we found about 750 patents of USA, China, Japan and other countries. The selected last year patents have emerged on the usage of geopolymeric mortars for 3D printing, grouting, sewage lining, and wastewater treatment.

Keywords: geopolymers, alkali-activated materials, market of geopolymers, patents on geopolymers, application in in civil engineering

The stability calculation of a П-shaped hinged frame is considered. The concept of r-like frames is introduced as frames with the same ratio r of the linear stiffnesses of the transom and the strut. It is shown that the parameter vcr , which determines the critical load on the frame, is the same for r-like frames. Approximate formulas allowing to determine the critical load parameter vcr and design lengths of compressed bars with an error not exceeding 2% are obtained.

Keywords: flat frame, stability, critical force, reduced length coefficient, r-like frames, approximation, least squares method

The article is based on modelling several variants of information diagrams of a corrugated monolithic ceiling of an industrial building. The information model has been transformed into an analytical model. The comparative analysis of all calculation models was carried out visually and in numerical aspect. The efficiency of BIM-technologies in design with the application of software complexes «Renga», «CAPFIRR-3D» and «LIRA-CAD» is also considered in the calculation and construction section. The comparative analysis of three variants of the joints of the beams and the slab of the covering was carried out. The analysis of the stress-distorted state of the calculation circuit was also performed.

Keywords: ribbed slab, industrial building, design of buildings and structures, BIM-technologies, calculation scheme, information model, rigid insert, stress-strain state, finite element method

The article discusses issues of improving the quality and safety of pedestrian and vehicle traffic in underground linear structures. The main parameters of traffic safety in tunnel-type transport structures are considered. The scope of application of luminescent and retroreflective materials in the construction and operation of concrete and asphalt concrete pavements has been determined. Recommendations are given for the use of special luminous materials in construction practice.

Keywords: concrete, asphalt concrete, reflective coatings, luminescent materials, traffic safety

In this article the existing principles of application of the illusion technique in architecture are considered. The classification of objects by purpose is presented, the key features of classification groups are highlighted. Examples of already existing constructed buildings with different typology are given and analyzed. The target direction of the article is based on the creation of the concept of volume (building) with the use of optical illusions to form a complex solution to clarify the overall concept of the object and achieve the effect of paradox in the viewer. The article also describes in detail the art-architectural and constructive solutions of the proposed concept with the definition of the exact location of the building in relation to the view and approach to it.

Keywords: Illusion, architectural volume, complex solution, paradox, dematerialization, visual perception, structural element, mirrored surface, hovering effect, tilt angle, master plan organization

The article describes the main problems associated with the principles of calculation and design of building structures of buildings and structures in seismically active areas in accordance with the provisions of the regulatory document SP 14.13330.2018. The difficulties that may arise when using foreign regulatory requirements in terms of design and calculation are noted. The calculation of a flat steel multi-story frame for the main and special combination of loads and impacts is considered. The frame calculation for a special combination is performed according to SP 14.13330.2018 with and without taking into account the additional requirements of foreign design standards ASCE / SEI 7-22, ANSI / AISC 341-22. The requirements of foreign standards were not taken into account in full, but only in terms of increasing the reliability of the structure, for certain positions. The change in the parameter of the frame metal consumption for various calculation options is analyzed. Conclusions are formulated and recommendations are given on how to reduce the metal consumption when calculating for seismic impact, taking into account the increase in the reliability of building structures.

Keywords: finite-element schemes, columns, crossbars, seismic action, steel frames, flat frames, design, limit states, material consumption, optimization, reliability, special combinations, combination factors

The article provides an analysis of the state of the rationing issue in terms of performing the calculation justification and design of reinforcement of reinforced concrete structures using external reinforcement systems based on carbon fibers. The normative documents of the Russian Federation and foreign ones are considered, the analysis of the use of external reinforcement based on composite materials for structures of various types of work is carried out, the disadvantages of existing calculation and design methods are highlighted. In conclusion, recommendations are given on the appropriate improvement of calculation and design methods.

Keywords: external reinforcement, carbon fiber, reinforcement, restoration

The article presents the results of the laboratory test and finite element modeling of the facade basket design for the outdoor unit of the split system. A comparative analysis of the obtained data is performed. During the modeling, the main possible design situations were taken into account and the perilous zones were determined, in which destruction is expected. To confirm the obtained design values, a full-scale test was carried out, in which wind pressure was modeled using two horizontally applied loads. Based on the test results, it was determined that the modeling method used corresponds to reality, and the nature of destruction and maximum permissible loads were also established. Based on this, a conclusion was made about the suitability of using the facade basket design option considered in the article for the specified operating conditions.

Keywords: finite element model, testing, load-bearing capacity, reliability, deformability, air conditioner basket, bracket, destruction

The article examines the two-dimensional flow around rectangular cylinders with an aspect ratio from 0.1 to 2.0 using the k-Realizable turbulence model with a Reynolds number of 2×E5. Numerical calculations in the ANSYS Fluent program have obtained changes in the coefficients of drag, transverse force and the Struhal number depending on the size of the prism section. The calculations were carried out at the intensity of turbulence of the incoming flow 2% and 4%. According to the results of calculations, it was found that with turbulence 4%, there is a good coincidence of the total aerodynamic characteristics with the available experimental data.

Keywords: flow around a rectangular cylinder, k-e Realizable turbulence model, aerodynamic characteristics of a rectangular cylinder

The architecture of multifunctional residential complexes (MFRC) is considered in the aspect of “resistance” to external factors and influences. There are four levels of formation of the MFRK: the level of urban planning structure; level of volumetric-spatial organization; level of functional and architectural planning structure; the level of compositional organization and search for the expressive appearance of the MFRK. At each of the identified levels, the “target” indicators of “sustainable architecture” are achieved. The process of forming the MFRC is considered as a sequence of combinatorial search stages and procedures based on modeling the geometric parameters of the visual model of the MFRC in order to get as close as possible to the “stability indicator”. Four methods of combinatorial search modeling are proposed: the method of “overlaying” planning frames; method of “tracing” the formative contour; method of “collaging” functional planning elements; a method of combining “regular grids” in the public, business and residential parts of the MFRK. To intensify combinatorial search procedures, it is proposed to use digital design technologies.

Keywords: university complex, transit urban spaces, scenario approach, functional-thematic zones, architectural and environmental modules

The paper presents the results of the survey of consoles of precast reinforced concrete columns of an industrial building under construction. The consequences arising from errors during the manufacture of columns, as well as the method of calculating the console are described. The survey was carried out in order to detect the position of the reinforcement in the consoles of reinforced concrete columns. When performing a survey of the technical condition, the following tasks were set: to determine the actual condition of the supporting structures, their mating nodes at the time of the survey, to establish the actual reinforcement of the structures, to give recommendations for the restoration (strengthening) of the bearing capacity of the column consoles.

Keywords: inspection, load-bearing capacity, concrete, column, reinforcement, strengthening

The article proposes an approach to determining the level of developer brand protection, which is understood as the reputation of the developer in relation to the regional market, formed in the Internet. The level of protection of the developer's brand takes into account the Gunning Nebula Index of text reviews about the developer, the average volume of words in text reviews about the developer, the number of negative text reviews about the developer, the total number of text reviews about the developer and the degree of competitiveness of the real estate market in the region. Estimates of the level of brand protection of developers in Perm and Yekaterinburg are given and analyzed. To reduce reputational risks and increase the level of brand protection, if it is not high enough, developers are recommended to regularly collect positive customer feedback, conduct brand protection audits, collect and classify negative feedback into true and false. True negative reviews should be discussed with customers, address the cause of the negative review, and then invite customers to remove or correct the negative review. When dealing with false negative reviews, you should seek their removal or publish detailed reasoned rebuttals to them online.

Keywords: real estate developer, online reviews, Gunning Nebula Index, brand protection, degree of competitiveness in the market, reputational risk management

The paper presents the results of the survey of the reinforced concrete monolithic foundation of a ball mill with central unloading. The consequences of errors made during the construction of the foundation of machines with dynamic loads, as well as the foundation monitoring methodology, are described. The survey was carried out due to an increase in the vibration level of the equipment installed on the foundation and the detection of foundation defects in the form of cracks and chips in concrete. When performing the technical condition survey, the following tasks were set: to determine the actual condition of the supporting structure at the time of the survey, to establish the physical and mechanical characteristics of the materials of the structure, to indicate the characteristics and dimensions of damage sufficient to determine the volume of repair and restoration work, to develop recommendations for further safe operation of the structure.

Keywords: inspection, bearing capacity, foundation, dynamic load, concrete, reinforcement, strengthening

The most important fields of 3d printing technologies. The patent's examples.

Keywords: 3d-printing, patents, civil engineering, industry, medicine

Modernization of university campuses in the context of the development of domestic higher education and science to increase the technological sovereignty of the country is one of the pressing problems of modern domestic architecture. The article examines the main factors that determine the need to modernize existing university campuses and influence its capabilities and tools. Based on the analysis of these factors, the main modern requirements for campus modernization are formulated.

Keywords: modernization, university campus, modernization factors, modernization requirements

The article analyzes the idea of architectural reserves proposed by Pskov architect and restorer Yu.P. Spegalsky in the middle of the XX century. The Pskov restorer proposed to allocate separate sections of the city center with ancient monuments on their territory as the basis for its development as an open-air museum. The plan was not implemented, but later this theory was used as the basis for successfully implemented modern restoration and architectural projects aimed at developing the urban environment of Pskov. The options for continuing the development of the idea in the near future are considered on the example of a complex formed by ancient defensive structures and a monument of constructivist architecture.

Keywords: Y.P. Spegalsky, architecture of ancient Pskov, creativity of A.A. Olya, restoration in Pskov, Mstislavskaya Tower.

The construction industry is undergoing a significant shift toward technological advancement and 3D printing is one of the groundbreaking technologies leading the way. 3D printing technologies a widely protected by many patents, mainly in USA & China. Petrone's team are focusing on the integrity and performance of structures built using 3D-printed LEGO-like concrete modules.

Keywords: 3d - printing for Civil & Military Engineering, review of last year patents, 3D-printed LEGO-like concrete modules

The article considers the numerical solution of the dynamic problem of interaction of a a building with a foundation. The developed algorithm and computer program are implemented on the example of calculating a 9-story frame building taking into account the operation of bored piles from the impact in the from of a given earthquake accelerogram.

Keywords: numerical modeling, bedrock, accelerogram, spline approximation, bored piles, partial frequencies, integration step

The article discusses the features and prospects of implementing distributed management of critical urban infrastructure facilities based on the principles of autonomy. Based on the analysis, the main technologies, directions of development and features of energy transfer in an urban environment are highlighted, contributing to the introduction of distributed management of urban infrastructure facilities. The study focuses on the analysis of the distributed structure of integrated security of critical urban infrastructure facilities and the development of general principles of distributed management of critical infrastructure facilities using the «Autonomous Building» technology. t is shown that the reliable and safe functioning of critical infrastructure facilities in the city is ensured through the synthesis of special technical systems for complex protection of the facility from major security threats based on the combined use of elements of life support and safety systems. At the same time, technical life support systems for autonomous objects of critical infrastructure of the city are built on the basis of the combined use of autonomous energy sources, including non-renewable energy sources, on the principles of joint operation of electric and static power converters, storage, frequency regulation and energy conversion, and technical safety systems of autonomous objects are built using combined optical and electronic means event detection and recognition with the ability to control the full spectrum of electromagnetic radiation.

Keywords: distributed management, technology, energy, energy transfer, urban infrastructure, critical facility, electrification, decentralization, automation, autonomy

The use of a solid analog and the involvement of an appropriate theory of stability made it possible to perform mathematical modeling and determine the parameters of the critical state of cylindrical mesh shells depending on the geometric characteristics and the number of half-waves of the shape of the loss of stability. The values of the critical load of cylindrical mesh shells are determined taking into account geometric and force factors. According to the results of calculations, the patterns of changes in the number of half-waves of the form of loss of stability and obtaining the minimum value of the critical load under the condition of maximum approximation of flexural and membrane stiffness are revealed and analyzed. A numerical example is shown in which the values of critical load and stiffness are determined, taking into account possible forms of loss of stability. The patterns of changes in these indicators for a given number of half-waves are established and analyzed.

Keywords: cylindrical mesh shells, mathematical modeling, critical load, stability, stiffness, number of half-waves

This study will examine the historical formation of the architecture of places of detention. The author gives space to the volumetric and planning transformation of prisons, examines the history of their emergence in stages and reveals the connection of these changes with the changes in the state and society as a whole. The study deals with the issues of restraint of freedom from inside and outside the penitentiary institutions, and partially touches upon the connection between fortification and penitentiary institutions in the sense of the continuity of the urban, architectural and landscape planning techniques of defence used. The study also presents examples of modern layouts; the types of layouts and the architectural means and techniques used in them to create a safe and comfortable environment are summarised in a table as material for analysis. In addition, as the results of the study, the main issues and directions of further development of prison architecture are indicated, and the author proposes models of optimal architectural and planning organisation in terms of security, surveillance and access control.

Keywords: security, prisons, penitentiary architecture, architecture, detention centres, design

In the construction sector, the reform of design and survey work allows us to take a fresh look at the state of engineering and geological research. The use of software systems provides an opportunity to automate this process during construction, reconstruction of buildings and structures in order to avoid the formation of landslide processes and reduce man-made risks. Limit equilibrium methods are used to determine the stability of a slope or an underground structure. Therefore, the purpose of the study in the article was to conduct engineering and geological surveys using various methods and then calculate the stability of landslide slopes. The sliding surfaces with the lowest coefficients of stability margin were selected by the optimization method for the calculated slopes.

Keywords: integration, reformation, method, construction, soil, landslide slope, man-made risk, surveys, automation

The paper discusses the use of carbon fiber composite materials for reinforcement of specimens made of pipe sections in tension under the action of internal pressure. Experimental investigations of steel pipes under the action of internal pressure both without reinforcement and with different number of reinforcement layers with carbon tape are described. The main interest is in the joint operation of the pipe wall and external reinforcement elements. Significant influence of external reinforcement on stiffness and deformability of the specimens is noted.

Keywords: high-strength fiber, carbon fiber, carbon tape, adhesion layer, pipe, external reinforcement system, polymer composites, tensile strength

Indirect reinforcement can significantly increase the strength and deformation characteristics of concrete. For the compressed zone of reinforced concrete beams, one of the most effective options for indirect reinforcement is transverse welded mesh. At the same time, the current regulatory documents still have a number of gaps in the methodology for calculating such structures. The article presents experimental data and calculation results for three series of reinforced concrete beams with indirect reinforcement of the compressed zone. Based on the calculation results, the shortcomings of the normative methodology are shown when performing calculations within the framework of the theory of limit states and assigning design values ​​for the strength of concrete with indirect reinforcement. Conclusions are drawn about the necessary sequence for calculating the design strength and deformation characteristics of concrete with indirect reinforcement.

Keywords: indirect reinforcement, beam, welded mesh, volumetric stress state, nonlinear deformation model, stress-strain diagram

To develop a methodology for assessing the strength of ring flanges, research was conducted on the load-bearing capacity of welded pipe joints of varying diameters. The study employed the component finite element method (CFEM) implemented in the IDEAStatiCa Connection software. To verify the obtained results, a numerical experiment was carried out using the ANSYS software package. The investigation considered several types of flange joints made from welded pipes with different diameters. Parameters were selected based on common sections used according to russian Series 3.400-8 (Issue 2). The study found that for all cases, the highest stresses occurred on the flange at the joint with the smaller diameter pipe. The analysis indicated that the CFEM's applicability should be limited to diameter-to-wall-thickness ratios (D1/t1) of up to 40. Beyond this threshold, the CFEM does not accurately predict the strength of the joints due to the significant deformation that occurs in the pipe walls, forming a truncated cone shape at the flange junctions. For practical applications, formulas are proposed to check the strength of ring flanges. These formulas account for the weakening of the plates by bolt holes and provide conservative results. The findings highlight the necessity for additional numerical and physical experiments to refine the methodology for cases with D1/t1 ratios exceeding 75. The proposed approach offers a practical solution for evaluating the strength of ring flanges in welded pipe joints of varying diameters, contributing to the development of relevant engineering standards.

Keywords: load-bearing capacity, ring flanges, welded pipes, assembly joints, strength, component method, numerical experiment