Wear Of Equipment Research Articles

The relevance of the issue of increasing the energy efficiency of the electricity conversion process in the current conditions of operation of the electricity distribution networks of Ukraine

The work sets out the basic conditions for the functioning of Ukrainian electric networks, including: the need to comply with the requirements of European integration; functioning in conditions of a deficit in generating capacity and market relations; changing the nature of electricity consumption; wear and tear of electric network equipment. The tasks that are associated with the conditions for functioning and require solutions for the reliable functioning of electric networks and further activities of Ukraine as a member of the European Union are indicated. The main tasks set out in the work include: improving the reliability of electricity supply; the need to increase the level of informatization, automation and energy efficiency. It is noted that on the way to solving the set tasks, the implementation of work on the reconstruction of electric networks is carried out, the basis for financing which is investment programs. The issue of improving the energy efficiency of the process of transforming electric energy under the current conditions of the functioning of the Ukrainian electric networks is revealed and analyzed. Based on the results of the analysis, it is established that the issue of improving the energy efficiency of the process of transforming electric energy is relevant at the time of reconstructing electric networks. It is indicated that the analysis of the energy efficiency of transforming electric energy can be carried out on the basis of a technical and economic model of the costs of transforming electric energy and the parameters that affect the size of the costs. It is noted that in the case of presenting the parameters included in the technical and economic models of costs for the transformation of electrical energy in the form of separate components, a competing effect is observed between the components. It is noted that the advisability of the formulation of general calculation methods for calculating the economic component during the review of the nominal power of transformers.

Optimization of Parameters and Comparison of Detection Signals for Planar Coil Particle Detection Sensors with Different Core Materials.

The cleanliness of lubricating oil plays a key role in determining the operational health of mechanical systems, serving as a critical metric that delineates the extent of equipment wear. In this study, we present a magnetic-core-type planar coil particle detection sensor. The detection accuracy and detection limit are improved by optimizing the magnetic field inside the sensor. The optimization of the magnetic field is achieved through the finite element simulation analysis of the coil and the magnetic core. First, the finite element simulation software COMSOL 6.0 is used to model the sensor in three dimensions (3D). Then, we study the distribution of the magnetic field under different coil radii, core conductivity levels, and other parameters. We obtain the sensor structure after optimizing the magnetic field. The sensor is made using experimental methods, and the iron particles and copper particles are detected. The results show that the lower limit of detection of iron particles can reach 46 μm, and the lower limit of detection of copper particles can reach 110 μm.

Leveraging artificial intelligence for competitive advantage: a case study of Samsung

The author examines how it is possible to use artificial intelligence to the advantage of an organization that operates in the technology industry. The main focus of the research was to identify how effectively and in what ways Samsung used AI technologies in its smart phones and home appliance product segments to improve functionality and usability as well as operational effectiveness. This was to have been achieved through the use of Artificial Intelligence in manufacturing processes as well as in various ways to deliver unique customized services to customer unlike the rival companies. This work also shows how Bixby, Samsung’s own AI assistant or smart IoT solutions all help towards creating a smarter environment, thereby building goodwill for the brand and generating additional revenue streams. The study further shows how Samsung supports that the application of AI can enhance a firm’s competitive position by pushing product differentiation, monitoring and anticipating equipment wear and tear and making better decisions from analyzed data.

ANALYSIS OF PASSENGER CARS FAILURES

The article is devoted to the technical condition analysis of the structural elements of passenger cars of the "Passenger Company" branch. The cars were operated by the regional branch "Odessa Railway" of JSC "Ukrzaliznytsia". The vast majority of domestic passenger cars have been in operation since the end of the last century and have already exhausted their resource. The service life of such cars has been repeatedly extended taking into account the condition of the body and frame. But the issues of the condition of the internal equipment of carriages, the level of its environmental safety, the compliance of comfort systems with modern requirements of the European Union have always remained outside the attention of researchers. The comfort systems in passenger cars, which were designed and manufactured in the 70-90s of the last century, do not meet modern EU requirements. This concerns both environmental standards and material and labor costs for their maintenance in working condition. The low level of comfort causes dissatisfaction among passengers, who choose other carriers. The existing passenger economy system must ensure repair and restoration work during the technical maintenance of cars between trips. To carry out these works, it is necessary to have a sufficient number of spare parts and equipment. During operational planning, heads of the department must take into account the labor intensity of the performed work. Currently, the calculation of these indicators is carried out using some averaged values. They do not take into account either the degree of wear of the car equipment, nor the place and nature of its operation. The lack of reliable information about the actual level of wear and damage of life support systems leads to unjustified overspending of material resources. In order to ensure the rational operation of the Passenger Company departments that prepare passenger trains for trip, it is necessary to create a solid scientific basis for the rational planning of repair and restoration work during maintenance based on factual information on the technical condition of the elements of the internal equipment and life support systems of passenger cars. At the same time, the required number of spare parts and equipment must be provided to restore operability when preparing a car for a trip. The results of the study will be used by the administration of the Passenger Company to develop organizational and technical solutions to restore the functionality of the cars.

Increasing Wear Resistance of Ploughshare by Electrofriction Treatment

Surface layers of agricultural machinery working bodies are subjected to intensive abrasive wear during operation, which leads to rapid wear of equipment and reduction of its service life. To increase the wear resistance of the working surfaces of tools, the method of induction cladding using ‘Sormait-1’ materials is widely used. However, after coating, additional heat treatment is required, which improves physical and mechanical properties of the material and increases its durability. When using electrofriction technology (EFT) hardening, the surface of the parts is subjected to melting under the influence of electric arcs, which affects the surface characteristics of the coatings. In this work, two types of surface treatment of L53 steel were investigated: induction cladding using ‘Sormait-1’ material, as well as a combination of induction cladding and subsequent electrofriction treatment. The coatings were characterized and compared with the substrate in terms of the following parameters: microstructure, phase composition, hardness distribution, and friction-wear characteristics. After induction cladding of the Sormait-1 material, a dendritic structure was formed; however, subsequent electrofriction treatment resulted in a reduction of this dendritic structure, which contributed to an increase in the hardness of the material. The average hardness of the coatings after electrofriction treatment was 786 HV0.1, which is more than three times the hardness of the substrate. Furthermore, the influence of structural characteristics and hardness on abrasive wear resistance was examined in accordance with ASTM G65 international standards. Field tests were conducted on plough shares before and after electrofriction hardening to evaluate their performance. Each ploughshare was scanned with a structured 3D scanner before and after use in the field. From the scan data, the cutting-edge profile was calculated and three key parameters were determined: linear wear, volumetric wear, and mass reduction. According to the results of field tests, it was found that the service life of the blades hardened by electrofriction technology was 12%–14% higher compared to serial blades processed by induction cladding with the use of ‘Sormait-1’ material. Operational tests of hardened plough shares confirmed the results of laboratory tests and proved the advantages of electrofriction technology for increasing the wear resistance of soil tillage machine working bodies.

Assessment of particulate matter concentrations and air quality index during road construction-related activities in Ghana

Road construction involves activities that emit pollutants, including particulate matter, which harms humans. This study determined and compared particulate matter (PM1.0, PM2.5 and PM10) levels and air quality index (AQI) at unpaved roads, asphalt overlay, chip-sealed and asphalt-producing sites in Ghana and the health risks posed by their exposure. It was conducted in the Ashanti and Ahafo Regions, Ghana and was cross-sectional using the low-cost sensor, PCE-RCM16. Data collection took place, January-May, 2020. The asphalt-producing, asphalt overlay, chip-sealed and unpaved road sites had mean PM10 concentrations of 12.7-fold, 7.4-fold, 6.1-fold and 2.6-fold respectively of the 2021 World Health Organisation (WHO) air quality guideline (AQG) daily limit, 45 μg m−3. The mean PM2.5 concentrations were 30.4-fold, 17.2-fold, 14.1-fold and 6.1-fold greater than the daily AQG limit, 15 μg m−3 respectively. The mean PM1.0 values were of grave concern. Using the AQI, the asphalt-producing and asphalt overlay sites were considered “hazardous”, chip-sealed site was “very unhealthy” and the unpaved sites were “unhealthy for sensitive groups”. Type of activity influenced pollution levels (p < 0.01). All the sites were polluted above the WHO limits. Authorities should ensure the wearing of personal protective equipment, strict adherence to the WHO AQG and apply appropriate sanctions to offending firms/workers.

Study on vertical-torsional chatter under asymmetric conditions in tandem cold rolling

The vibrations generated by the rolling mills significantly impair the production quality and efficiency of cold tandem rolling. Considering that the main drive system constitutes one of the energy sources of vibration, this study integrates the vertical structure of the rolling mill with the torsional structure of the main drive system for a comprehensive analysis. This study establishes an asymmetric dynamic rolling force model that accounts for the structural asymmetry of the rolling mill, the asymmetric power transmission between the upper and lower connecting shafts of the main drive system, and the long-term wear and friction conditions of the mechanical equipment. Furthermore, this study accounts for the speed differential between the upper and lower work rolls induced by torsional vibrations. Based on these interdependent parameters, this study develops a rolling mill vibration coupling model to comprehensively assess stability. The validation of the model confirms its high accuracy. Variations in rolling torque under different roll speed ratios, friction coefficient ratios, and roll diameter ratios were analyzed, along with the impact of the cross-shear zone's proportion on system stability under key rolling parameters. Furthermore, changes in rolling torque, amplitude, and the cross-shear zone during unstable operating conditions were examined. Finally, the interaction between the vertical and torsional structures was studied, providing a theoretical foundation for optimizing process parameters and mitigating vibrations in the continuous cold rolling process.

LOSSES OF ELECTRICAL ENERGY DUE TO ITS LOW QUALITY AT PUMPING STATIONS OF HEATING NETWORK ENTERPRISES

The issue of increasing the reliability of the facilities in the energy system of Ukraine is considered. It is noted that Ukraine lacks sources of electric energy as a result of hostile actions. In addition, the level of electric energy losses is very noticeable. Even according to pre-war statistics, the level of losses exceeded 10 % of all energy produced. And this was a consequence of the wear and tear of both electrical equipment and insufficient quality of electric energy. And as a result of hostile actions, the destruction of energy equipment led to an even worse decrease in the parameters of the quality of electricity. The priority is to maintain the operability of the energy system, while quality indicators are relegated to the second place. For most electricity-consuming equipment, deterioration in the quality of electricity can have a multiplier effect. Manifesting itself as a sharp increase in losses. For enterprises whose work provides for the vital needs of the population, the quality of electric energy is not a criterion. The main goal is to maintain operability. Such enterprises also include enterprises of heating networks. Almost all devices and equipment of heating companies operate on electricity. Forced movement of the coolant in the network is created only by electric pumps receiving torque from asynchronous electric motors. Such motors are characterized by increased losses of electrical energy if its quality is poor. Measurements of the quality of electrical energy were made at two different heat supply enterprises. The article presents the results of the measurements. Despite the fact that the heat supply enterprises are very different (the first serves more than 30 thousand residents, the second – more than 8 thousand residents), the results of the measurements show the affinity of problems with the quality of electrical energy. The overwhelming majority of electrical energy quality indicators do not meet the requirements for the quality of electrical energy. The most critical deviations are in the values of average voltage and average positive sequence voltage, which may not meet the standard in 100 measurements out of 100. The deviation of the voltage asymmetry coefficient for zero sequence also exceeds the standard values. The authors draw attention to the presence of a deviation of the average coefficient of the n-th harmonic component of voltage in all phases. The specificity of the operation of heat supply enterprises' equipment is that their operating modes are continuous throughout the entire heating season. And losses in the network can accumulate. In addition, one of the consequences of using low-quality electricity is a reduction in the service life of electrical equipment. The authors propose general methods for correcting the situation and emphasize the need to conduct a study of electrical equipment of heat supply enterprises in order to develop measures to improve their operation and reduce energy losses.

Effect of Electrofriction Treatment on Microstructure, Corrosion Resistance and Wear Resistance of Cladding Coatings

In recent years, the issue of increasing the wear resistance of the working bodies of agricultural machinery designed for cutting and breaking the soil has received special attention. The surface layers of working bodies of agricultural machinery during operation are subjected to intensive abrasive wear, which leads to rapid wear of equipment and a reduction in its service life. The induction cladding method using materials such as Sormait-1 is widely used to increase the wear resistance of tool working surfaces. However, after coating, additional heat treatment is required to improve the physical and mechanical properties of the material and increase its durability. In electrofriction technology (EFT) hardening, the surfaces of the parts are subjected to melting under the influence of electric arcs. In this work, three types of surface treatment of L53 steel have been investigated: induction cladding using Sormait-1, electrofriction treatment, and a combination of induction cladding followed by electrofriction treatment. The microstructure was analyzed using optical microscopy and scanning electron microscopy. Erosion and abrasion tests were carried out in accordance with ASTM G65 and ASTM G76-04 international standards to evaluate the wear resistance of the materials under mechanical stress. A dendritic structure was formed after the induction cladding of the Sormait-1 material, but subsequent electrofriction treatment resulted in a reduction of this dendritic structure, which contributed to an increase in the hardness of the material. However, the highest hardness, reaching 965 HV, was recorded after electrofriction treatment of L53 steel. This is explained by needle martensite in the structure, which is formed as a result of quenching. Further, the influence of structural characteristics and hardness on erosion and abrasion wear resistance was examined. The analysis showed that the material microstructure and hardness have a decisive influence on the improvement of wear resistance, especially under conditions of intensive erosion and abrasive friction.

SAFETY ASSURANCE TRIPPING OPERATIONS IN OIL AND GAS PRODUCTION

The article discusses the issues of industrial safety at the enterprises of the oil and gas industry, in particular during the performance of tripping operations. The relevance of the research topic is justified, based on the fact that this industry in our country (oil production) occupies one of the leading positions in the world, and all processes are accompanied by tripping operations, therefore, the issue of ensuring industrial safety remains relevant.The problems of the oil and gas sector and their impact on the drilling process, in particular, high wear of equipment and the human factor, were considered.The study focuses on non-compliance with occupational health and safety standards, as well as shortcomings in the risk management system that contributed to the occurrence of these emergencies. Rostekhnadzor data related to the distribution of industrial injuries were analyzed. Cases of violation of industrial safety regulations during tripping operations were considered, which led to severe traumatic injuries and fatal outcomes.Based on the analysis of regulatory requirements in the field of production safety of tripping operations, shortcomings were found, and recommendations were made for making changes based on the existing safety status at the facilities of such problems as equipment deterioration, the relevance of existing protective equipment.The second block is aimed at considering the technical features of the receiving walkways and identifying design imperfections during their operation.The article proposes a shock-resistant protective limiting device of its own design, which will contribute to improving the production safety of tripping operations when drilling wells. The use of this device will minimize the risks of damage to equipment and reduce the likelihood of emergencies. Due to its simplicity and the use of available materials, the device has high strength and durability, which ensures its reliable operation in conditions of increased loads and difficult climatic conditions. In addition, the introduction of such devices in production processes helps reduce the cost of repair and maintenance of equipment, as well as increase the overall efficiency of drilling operations by reducing downtime and unplanned shutdowns associated with incidents.

Rationale and design of the randomised, controlled Percutaneous coronary intervention using Assisted Robotic TechnologY (PARTY) trial

IntroductionPercutaneous coronary intervention (PCI) is performed by interventional cardiologists who, over their career, are exposed to substantial X-ray radiation and also face potential musculoskeletal injuries from the prolonged wearing of...

An approach to solving the problem of equipment replacement using periodic fuzzy graphs

Monitoring equipment wear is an important problem that requires constant attention, since this process can lead to a decrease in its efficiency, accidents or breakdown. The problem of replacing equipment is a production problem, in which it is necessary to consider many factors that influence the efficiency of the enterprise itself. This paper examines various formulations of the equipment replacement problem: in the classical formulation of dynamic programming, in the stochastic formulation and fuzzy graph representation. The idea to solve the problem using periodic fuzzy graphs is proposed. We also consider the age of equipment when determining the wear coefficient, determined by the degree of belonging to a particular class of parameters defined in the formulation of the problem. Periodic fuzzy graphs allow considering the problem of replacing equipment not for one type of equipment, but for a complex of machines, which ensures the scalability of the classical dynamic programming problem under uncertain initial data. When determining the membership function, it is possible to consider those factors that may influence the solution of the optimization production problem. Setting the problem in a fuzzy form makes it possible to forecast and plan the activities of an enterprise for future periods.

Recent Advances in Biomimetic Related Lubrication

Friction is ubiquitous in industry and daily life, which not only leads to the wear and tear of equipment and machinery, but also causes a lot of energy waste. Friction is one of the significant factors leading to energy loss in mechanical systems. Therefore, it is essential to minimize friction losses. Creatures in nature have evolved various surfaces with different tribological characteristics to adapt to the environment. By studying, understanding, and summarizing the friction and lubrication regulation phenomena of typical surfaces in nature, various bionic friction regulation theories and methods are obtained to guide the development of new lubrication materials and lubrication systems. This article primarily discusses the study of lubrication mechanisms through biomimetic design, which is mainly divided into chemical approaches, structural strategies, and chemical–structural coupling approaches. From the chemical point of view, this paper mainly summarizes joint lubrication and engineering lubrication in biomedicine, with inspiration from lotus leaves, fish skin, and snake skin, each with unique antifriction structures which are famous for their super hydrophobicity in nature. Finally, chemical–structural coupling simulates the lubrication mechanism of natural organisms from the joint action of biological structures and chemical substances, and is applied to coating design, so as to reduce the friction and wear on coating surfaces, improve the durability and anti-pollution ability of coatings, significantly improve the tribological performance of mechanical systems, promote scientific innovation, and promote energy conservation, emission reduction, and sustainable development.

Negative impact of vibration on process pipelines of a compressor station with electrically driven gas pumping units

Relevance. In gas industry, the amount of equipment that has outlived its intended service life is increasing every year. In accordance with the law “On Industrial Safety of Hazardous Production Facilities,” compressor stations are dangerous objects, the reliable operation of which largely determines the condition of main gas pipelines. Technological pipelines of a compressor station are important objects of this system. They are subject to strict requirements due to the action of static and dynamic loads on them. Reliability of compressor stations is based on the results of a study of the condition of the object and the main factors affecting increased wear of equipment. The solution to wear problem is timely monitoring of equipment, in particular level measurement and determining the causes of pipeline vibrations using vibration diagnostics methods, and frequency and modal analysis methods. Aim. To study the causes of increased dynamic loads on the technological piping that arise during the operation of electric and gas pumping units at a compressor station using vibration monitoring methods. Methods. Vibration monitoring methods to analyze the causes of increased vibration values in the process piping of a compressor station with an electric gas pumping unit. Results and conclusions. The authors have measured vibration in a wide frequency band and assessed the technological condition of the main equipment of the compressor station with EGPA-6.3/8200-56/1.44-R based on the regulatory documentation STO Gazprom 2-2.3-324-2009. The main frequencies of the root-mean-square value of the vibration velocity, at which the highest vibration values were observed, were identified, and a modal analysis was performed using ANSYS software. Based on the results of natural studies and modal analysis, it was concluded about the occurrence of resonant high-frequency oscillations, multiple of the rotor rotation frequency.

Testing the functionality of OLGA software for determining optimal oil transport modes to prevent solid particle deposition

Background: During operation, all mechanical impurities entering the collector through the flow lines settle at the bottom due to a decrease in flow velocity. This leads to a reduction in the capacity of the pipeline network, increased pressure, and premature equipment wear. To address this issue it is essential to understand the dynamics and intensity of sludge formation at the bottom of the pipeline. Aim: Evaluate the functionality and efficiency of the dynamic multiphase flow simulator in addressing challenges related to the transport of borehole fluid containing solid particles. Materials and methods: To build a mathematical simulation of multiphase flow with solid particles using OLGA specialised software, we selected one of the oil gathering lines in field N, with a diameter of 159х10 mm and a length of 1600 m, as the study object. This oil gathering line collects production from 16 wells. The OLGA simulator was used to model the process and measure flow parameters with different particle diameters, predicting the dynamics of variables such as time-varying flow velocities, fluid composition, temperatures, and particulate deposition. For a flow with a particle diameter of 104 µm, active precipitation occurs at flow rates between 200 and 300 m³/day. At flow rates of 400 m³/day and above, the velocity is sufficient to carry the particles without significant accumulation in the pipeline. Results: The software enabled the calculation of the dynamic system for different solid particle diameters in multiphase flow, addressing the challenge of evaluating the dynamics of solid phase accumulation in the pipeline and determining the fluid flow velocity required to prevent sludge formation. The software is suitable for implementing simulation modelling to develop technical solutions that minimise the risks of solid particle deposition in oil gathering pipelines during the operation of on-shore infrastructure facilities. Conclusion: The software enabled the calculation of the dynamic system for different solid particle diameters in multiphase flow, addressing the challenge of evaluating the dynamics of solid phase accumulation in the pipeline and determining the fluid flow velocity required to prevent sludge formation. The software is suitable for implementing simulation modelling to develop technical solutions that minimise the risks of solid particle deposition in oil gathering pipelines during the operation of on-shore infrastructure facilities.

Research on Abnormal Behavior Monitoring in University Laboratories Based on Video Analysis Technology

The safety management of laboratories is of utmost importance in the construction and management of university laboratories. Abnormal behaviors such as smoking, incorrect wearing of personal protective equipment (PPE) like lab coats, hats, masks, and gloves pose significant safety hazards. In this paper, in order to improve the level of laboratory safety management and effectively provide an alert in the case of unsafe behaviors, video analysis technology is employed to achieve abnormal behavior recognition and monitoring through steps such as human key point detection, posture estimation, and behavior recognition. Firstly, the human pose estimation algorithm YOLO is used for human detection, followed by the extraction of human key points after segmentation. Finally, spatiotemporal graph convolution is used for feature detection and classification of abnormal behaviors. The experimental results show that the accuracy of abnormal behavior detection and recognition based on human key points reaches over 85%, which is of great significance for safety management and behavior warning in university laboratories, and thus, improves the efficiency and level of laboratory safety management.

Research on risk management of ship maintenance projects based on multi agent swarm model simulation method

In recent years, the role of naval ship power has become increasingly prominent in regional conflicts and military operations worldwide, and the powerful capabilities demonstrated by naval forces have also been valued by countries around the world. While naval forces are frequently deployed to carry out various tasks, the intensity of equipment wear and tear on ships is also significantly increasing, posing a huge challenge to the maintenance and support capabilities of ship equipment. In the actual process of ship equipment maintenance, a series of risk factors such as cost, schedule, and quality will have a significant impact on the entire ship maintenance project, and even affect the success or failure of the entire project. This article first decomposes the project process of ship maintenance projects, further analyzes the various risk factors of ship maintenance projects based on the project decomposition situation, and then distinguishes the overall project, project process, and project risk factors to establish an intelligent agent group model for simulation analysis. Through the above simulation analysis, we will conduct in-depth research on the specific impact of project risks on ship maintenance projects, and analyze and verify the positive role and practical significance of project risk management in project risk control and project efficiency improvement. In the process of the above research content, methods and measures for risk management of ship maintenance projects are proposed, providing scientific and efficient risk management suggestions for such projects, improving the scientific management efficiency of ship maintenance projects, and contributing to the improvement of the quality and efficiency of project management.

Enhancing plate compactor efficiency: A study on frequency effects for different soil types

In this study, compaction tests on three soil types (glacial aggregate mixture, amphibolite aggregate and sand-gravel mixture) were conducted in a full-scale plate compactor experiment under different frequency scenarios, specifically between 74 and 84 Hz. The experimental approach included measuring bulk density through photogrammetry and soil sampling at different layer depths. This methodology enabled the direct assessment of Relative Compaction (RC). Furthermore, soil stiffness was measured during compaction via a lightweight dynamic plate. Findings revealed that lower compaction frequencies generally resulted in denser compaction near the surface, while higher frequencies improved compaction at greater depths. Additionally, the study explored the relationship between dynamic modulus and RC. The study highlights the need for advanced, rapid compaction assessment methods, given the limitations of current techniques. The results indicate that within the analyzed range of compaction frequencies, both the dynamic modulus and RC requirements are achieved after the same number of compactor passes, regardless of the selected frequency scenario. Therefore, opting for a lower frequency can reduce fuel consumption and equipment wear while maintaining compaction objectives, leading to better overall efficiency.

A Lab-Scale Evaluation of Parameters Influencing the Mechanical Activation of Kaolin Using the Design of Experiments.

This research investigates the mechanical activation of kaolin as a supplementary cementitious material at the laboratory scale, aiming to optimize milling parameters using the response surface methodology. The study evaluated the effects of rotation speed and milling time on the amorphous phase content, the reduction in crystalline kaolinite, and impurity incorporation into the activated clay through the Rietveld method. The results demonstrated that adjusting milling parameters effectively enhanced clay activation, which is crucial for its use in low-carbon cements. High rotation speeds (300/350 rpm) and prolonged grinding times (90/120 min) in a planetary ball mill increased the pozzolanic activity by boosting the formation of amorphous phases from kaolinite and illite and reducing the particle size. However, the results evidenced that intermediate milling parameters are sufficient for reaching substantial degrees of amorphization and pozzolanic activity, avoiding the need for intensive grinding. Exceedingly aggressive milling introduced impurities like ZrO2 from the milling equipment wear, underscoring the need for a balanced approach to optimizing reactivity while minimizing impurities, energy consumption, and equipment wear. Achieving this balance is essential for efficient mechanical activation, ensuring the prepared clay's suitability as supplementary cementitious materials without excessive costs or compromised equipment integrity.

Competitive position of sand-lime bricks in the domestic market, threats and opportunities for manufacturers

The problem of assessing the prospects of silicate bricks in the domestic market of small wall materials is discussed. The solution to this problem is based on the results of the analysis of the market situation, consumer preferences and competitiveness of silicate bricks. It is shown that in the period from 2014 to 2021 due to the stronger competitive position of autoclaved aerated concrete blocks and face ceramic bricks, the capacity of the market of silicate bricks decreased, its production volume and share in the structure of consumption of small-piece wall materials. The results of marketing research conducted on the basis of online questionnaires of respondents are presented, according to which the majority of respondents consider face ceramic bricks to be the material that best meets their requirements in terms of quality and appearance. The calculations showed that despite the fact that ceramic bricks have almost equal positions in terms of technical parameters and worse positions in terms of aesthetics, the most competitive material is, nevertheless, silicate bricks, which have a relatively low price. A number of threats for silicate brick producers include a decrease in demand for products, a high degree of wear and tear of technological equipment, dependence on foreign supplies of pigments, spare parts and components for equipment, insufficient level of professional competence of the personnel, etc. It is expected that in the future a number of manufacturers of sand-lime bricks will have to face the following challenges. It is assumed that in the future the ordinary silicate bricks will apparently “leave” the construction market, in connection with which manufacturers will have to focus on improving the quality and aesthetic parameters of facial silicate bricks while maintaining an attractive price for consumers.