Introduction. The storage of pond ash at ash dumps has a negative impact on the environmental situation in the nearby settlements, dumps constantly dust and pollute water sources. To solve this problem, it is proposed to use ash from pond ash as a component of mixed binder. Since the specific surface area of pond ash is different throughout the dump, it is necessary to study its influence on the strength set of mixed binder under different curing conditions.Materials and methods. The equipment on which the experiment was carried out is listed. To determine the specific surface ПСХ-12 device was used, ash drying was carried out in a desiccator. The samples were stored in a normal solidification chamber. The chemical composition of pond ash from TPP-5 of Omsk was presented.Results. Experimental data on the strength of samples of mixed binder at the age of 1,3,7,14,21,28,90 days of normal hardening and data on the strength of samples after heat and humidity treatment are presented. Durability of mixed binder composition with specific surface of hydraulic ash of 460-490 m2/kg under normal hardening conditions amounts to 42.57 MPa which corresponds to natural strength. The composition with the use of pond ash 460-490 m2/kg after water removal increased strength by 12% in comparison with the control composition. Compositions with specific surface of wet pond ash 220-250, 340-370, 650-700 m2/kg show durability results lower than the control ashless composition irrespective of hardening conditions.Discussion and conclusions. It is proved that the use of pond ash with a specific surface of 460-490 m2/kg is rational. Its strength under normal conditions of hardening is 42,57 MPa, which corresponds to the strength of the concrete. The composition with the use of wet pond ash 460-490 m2/kg after heat and moisture treatment has an increase in strength by 12% compared to the control composition. Increased strength of mixed binder compositions is associated with acceleration of pozzolanic reaction in them, the products of which have a positive effect on the strength of the products.

Introduction. Welded I-beams with a transversely corrugated wall when loaded in the wall plane are calculated for overall stability in accordance with paragraph 20.6.3.11 of СП 294.1325800.2017, change 2 from 06/15/2021. Here, a separate centrally compressed girder belt is calculated for overall longitudinal stability from the plane of the beam wall as an element pivotally supported at the ends. This does not take into account the joint work of the compressed belt with the wall, supporting ribs, stretched belt.The authors set a goal to show by calculation using the examples of six beams that if, in comparison with the calculation according to СП 294.1325800.2017, the joint work of the compressed belt with the wall, support ribs, stretched belt is taken into account, then the calculated critical load of the total loss of stability of the corrugator will be greater. And this increase is the more significant, the lower the height of the corrugator. At the same time, the authors limited themselves to considering beams with a ratio of sizes and critical loads that ensure the operation of steel in the elastic stage with loss of overall stability.Materials and methods. The general stability of split beams with a transversely corrugated wall was studied by calculation in three ways: according to СП 294.1325800.2017, in the LIRA-CAD PC by modelling beams with shell elements, including belts, walls and support ribs, and according to CП 16.13330.2017, considering a welded I-beam with a flat wall equivalent to the criterion of general stability.The results of the study. The data of calculation of critical loads of the first form of loss of general stability of six split beams of the Zeman range with height are given 333, 500, 750, 1000, 1250, 1500 with a span of 6.0 m in three proposed ways with loading of the upper belt with a uniformly distributed load in the wall plane without loosening the compressed belt in the span and loosening the support sections from the wall plane and from rotation relative to the axis of the beams.Discussion and conclusions. For beams with a wall height of 333 mm, taking into account the joint work of the compressed belt with the wall, stretched belt, support ribs showed an increase in critical load in comparison with the calculation according to СП 294.1325800.2017 by 24%. With an increase in the height of the beams to 900-1000 mm, the difference in the values of critical loads calculated taking into account the joint work of the beam elements and according to СП 294.1325800.2017 non-linearly decreases to 3%. And for corrugated rollers with a height of 1000-1500 mm, this difference is less than 3%, which shows that it is possible to perform calculations of beams with a transversely corrugated wall of the Zeman range with heights of 1000-1500 mm for overall stability with sufficient accuracy for engineering calculations according to СП 294.1325800.2017.

Introduction. The article formulates the problems statement about equilibrium states in the model of a generalized transport system of the city, consisting of a street and road network, centers of mass gravity, places of residence of people, vehicles, as well as road users themselves, including passengers. The solution of these problems makes it possible to identify the equilibrium distributions of the system elements over various subsets of states (a subset of the elements of the road network; a subset of the center of mass gravity; a subset of trips of a certain type, etc.), depending on the type of vehicle, individual preferences, knowledge about the state of the transport system and other factors.At the same time, the transport system is considered as an object of research within the framework of the theory of macrosystems. A set of problems statements on the search for equilibrium states of the transport system for various modelling objects has been compiled for various structural levels (scales) of the objects under consideration.Materials and methods. In this paper, the theory of transport macrosystems is applied, which follows from a wellknown scientific discipline - the theory of macrosystems. Among its tasks there are statements about the distribution of elements over subsets of states and problems about the equilibrium of the system as a whole. In macroscopic systems, by definition, the stochastic behavior of a large number of elements transforms the deterministic behavior of the system as a whole. A macro system is thus a dynamic converter of the chaotic behavior of elements into a certain set of behavior parameters (phase variables) forming a space of small dimension. Therefore, within the framework of the theory of macrosystems, the basic concepts of entropy maximization at equilibrium states of the system are used. In this case, the distribution function of macrostates is selected depending on the method of filling some states with elements from the corresponding subsets; the necessary values of a priori probabilities and proofs of parametric properties of models of macrosystems with various statistics (Fermi-, Einstein- and Boltzmann-distributions). On the basis of the theory of macrosystems, for example, problems are solved to find equilibrium in such systems as: 1) megapolis with its functional and spatial structures (probabilistic states of hierarchical systems), 2) transport networks of cities formed by the movement of vehicles and residents of the city between different areas (distribution of trips along routes in the network); 3) logistics systems in the interregional exchange of products (problems of economic equilibrium in the exchange of resources).Results. The paper presents the results of research concerning the uniform description of the elements of the road network and the centers of mass gravity as components of the general transport system of the city (agglomeration) in the framework of the theory of transport macrosystems. At the same time, the study identifies various structural levels of description that can be used to solve particular problems, for example, finding equilibrium in individual subsets of the transport system, such as groups of centers of mass gravity of a certain type, or traffic flows on routes, stretches, network sections, etc.Discussion and conclusions. Within the framework of the work, the following tasks were solved: a description of the structural levels of the objects of the road network and the centers of mass gravity as the main components of the model of transport systems was developed; the formulation of problems about the equilibrium states of transport systems at the corresponding structural levels was developed; the analysis of the obtained methodology was performed; a methodological analogy is established between different subsets of states at the same structural level, for example, between the centers of mass gravity and elements of the road network as objects of modeling by methods of the theory of macrosystems (this analogy can be extended to other subsets of states in transport systems, for example, types of transport systems, travel purposes, parking spaces, subsystems of the intelligent transport system and much more).

Introduction. One of the problems of developing new generation concrete is to ensure the rational granulometric composition of a mixture of cement and fine additives to ensure the densest packing of all particles of the cement system. In this regard, the paper considers the optimization of the dispersed structure of quartz filler, taking into account its specific surface area, concentration in the composition of the binder and water-solid ratio.Materials and methods. In the studies, Portland cement TSEM I 42.5 N (GOST 31108-2020) of ZAO Belgorod Cement and fine quartz were used. The compressive strength samples were tested on a PGM-100 MG4 laboratory press. The granulometric composition of the fillers was determined using Analysette 22 NanoTec plus laser diffraction particle size analyzer.Results. The conducted studies have allowed to determine that the optimal dosages of microdispersion filler are closely related to the specific surface area and the V/T of the mixture. It is shown that with an increase in the dispersion of quartz filler, a decrease in the range of optimal dosages is observed, which narrows with an increase in the water-solid ratio. The mechanisms of structure formation affecting the properties of dispersed-optimized cement systems are described. With the growth of the specific surface of the filler, the specific activity of the unit of the surface of the filled binder decreases, which is accompanied by a decrease in the number of crystallizationcoagulation bonds between the hydrate phases of cement.Conclusion. The experimental data obtained confirm that for a cement stone made of a mixed binder, the watersolid ratio is no less significant than the concentration of a mineral additive, therefore, a decrease in the V/T of mixed cements is a necessary condition for achieving a given strength.

Introduction. Reducing the operating costs of motor fuel for cars is possible through the use of cheaper and at the same time less environmentally harmful alternative energy sources. The main problem with the use of these energy sources, especially for 1 category cars, is the underdeveloped infrastructure of the network of filling stations for alternative fuels. The main alternative type of motor fuel in the Russian Federation is natural gas. The use of compressed natural gas as a vehicle fuel on 1 category cars significantly increases zero mileage due to the remoteness of filling stations, which reduces the efficiency of using natural gas. The purpose of the research is to develop a methodology for calculating the cost of refueling with various types of motor fuel for 1 category cars, taking into account the location of refueling points (gas stations / gas filling stations / filling stations).Materials and Methods. The research presents a methodology for calculating the cost of refueling with various types of motor fuel, developed on the basis of a multivariate analysis of the vehicle performance, a given 1 category cars route, the driver’s work on the route, and the existing infrastructure of the filling station network. The scientific novelty is the establishment of the dependence of the cost of refueling with motor fuel on the type of fuel used, the existing infrastructure of the network of filling stations, the average daily mileage and on the technical and economic indicators of 1 category cars.Results. The developed methodology was tested at the enterprises that 1 category cars cargoes in the territory of Omsk. It has been established that for 1 category cars, when carrying out the process of transporting goods in Omsk, the cost of refueling with motor fuel will be from 1.77 to 15.62% of the average cost movement by the route.Discussion and conclusions. The methodology allows to determine the impact of the fuel used on the 1 category cars operating costs, to select an effective motor fuel, as well as to account for the cost of refueling with motor fuel and more accurately determine the cost of transporting goods.

Introduction. The operation practice for the rolling stock of road transport during the transportation of goods in the harsh conditions of the Far North (Republic of Sakha (Yakutia)) shows the necessity to organize measures related to ensuring road safety on road sections with ups and downs. To prevent rolling stock from running off the road and overturning, tractor equipment is used as a tractor for road transport, the use of which is time-consuming. The purpose of this article is to develop a new theoretical toolkit for planning the work of the rolling stock, which makes it possible to determine the time spent on transportation.Materials and methods. The study uses field observations for trips, during which tractor equipment was used as a tractor for road transport on cargo transportation routes, where movement was carried out on descents and ascents.Methods of probability theory and mathematical statistics were used to determine the probability of occurrence of an event, the values of confidence intervals for the time of movement of the rolling stock, taking into account the confidence probability of 0.95. As the basis of the performed research, the scientific work of scientists on the planning of the work of the rolling stock was used, taking into account the peculiarities of the organization of road traffic during the transportation of goods in difficult operating conditions.Results. The authors determined the time spent on the transportation of goods using tractor equipment as a tractor for planning the work of IVECO-AMT 733910 С/Т rolling stock on six routes. The value of the probability of using tractor equipment on the studied routes for planning the operation of IVECO-AMT 733910C/T rolling stock has been established.Conclusions. The presented values of the movement time of the IVECO-AMT 733910 С/Т rolling stock when transporting goods using tractor equipment as a tractor can be used for practical use in planning from December to March when transporting collapsible structural elements of drilling rigs and property of drilling crews.

Introduction. Mixing of dry components in mixers is one of the most important stages of any technological process in the manufacture of a composite material. To date, various technologies use a wide variety of mixing equipment, which is characterized by different principles of mixing and design solutions. Of particular interest for the preparation of high-quality and homogeneous mixtures for heat-insulating purposes is a pneumatic mixer with a spiral energycarrying tube. The article presents the results of studies using the method of mathematical planning of the fullfactor ПФЭЦКРП24 experiment, which makes it possible to most adequately assess the ongoing processes while minimizing systematic errors.Materials and methods. In the work, ЦЕМ 0 42,5Н ГОСТ 31108–2020 Portland cement with a specific surface area of 308 m2 / kg, sand of the Volsky deposit were used as raw materials for testing. Expanded vermiculite obtained as a result of heat treatment of natural vermiculite at a temperature of about 700°C was used as a light filler.Results. Heat-insulating mixtures prepared in a pneumatic mixer with a spiral energy-carrying tube ensure the production of heat-insulating mortars with stable density values of 1420 kg/m3, having sufficient compressive strength of 3.3 MPa, and guarantee high heat-shielding properties in building structures.Conclusion. The developed design and the conducted studies made it possible to establish the high efficiency of the proposed mixer, which provides a uniform distribution of the particles to be mixed, high homogenization and the creation of conditions for accelerating the physicochemical interactions in the created mixture with subsequent mixing of the prepared mixture with water and the formation of the required internal structure of the created composites.

Introduction. The requirement for modelling the dynamic processes of a hoisting mechanism in real operating situations has been revealed. The necessity of increasing the accuracy of moving effort description for the most common types of crane hoist drive control has been determined.Materials and Methods. The operation of a single-speed electric motor with squirrel-cage rotor without speed control, with a phase rotor and additional resistors in the rotor winding and with a squirrel-cage rotor and control by a frequency converter has been considered. The static characteristic of the electric motor is taken as the initial function. The Clauss formula with the corresponding values of the parameters synchronous speed, critical force and critical slip was used to take into account the driving force of the motor for frequency control and for relay-contactor control and a motor with a phase-rotor and additional resistances in the rotor circuit.Results. The dependences for the motor driving force with the most common methods of speed control of the crane hoisting mechanism drive are presented. In the case of the frequency control system, the form of the motor driving force is given in the case of steady-state motion and in the case of transient starting/braking processes when the corresponding algorithms are implemented by a frequency converter. Experimental and theoretical graphs of the load lifting processes for the cases of lifting with pickup in the relay-contactor control system and with elastic pickup in the frequency control system are given.Conclusion. The conclusion about applicability of static mechanical characteristic for description of electric motor operation in crane drives is given. The presented dependences provide an opportunity to model the full working cycle of the hoisting mechanism. The dependences are valid both during steady motion of the mechanism and during transients. It is concluded about the use of the dynamic model taking into account the presented form of the motor driving force for practical purposes for the analysis of the crane operation with regard to the effect of the lifting capacity limiter.

Introduction. Road safety is largely determined by the technical condition of the vehicle, and especially control systems. The braking system is one of them. To improve its efficiency, various assistive electronic systems are now widely used. These systems control the vehicle through wheel braking mechanisms. Brake pads are a constituent element of a friction-type wheel brake mechanism. The efficiency of the vehicle braking system depends on its quality, regardless of the presence of auxiliary electronic systems. The use of brake pads with a wide spread of friction coefficients can have a significant impact on braking performance.Materials and methods. To conduct experimental studies, a methodology for conducting them and processing experimental data was developed, as well as a laboratory setup was made. Arduino Uno R3 analog-to-digital converter was used as an instrumental component of the stand for converting mechanical movements into an electronic signal.Results. In accordance with the proposed methodology, four pairs of brake pads were tested. As a result of processing the experimental data, it was found that the difference in the values of the friction coefficients of the brake pads can cause a difference in the magnitude of the braking forces on the wheels from 8 to 19%.Discussion and conclusions. The difference in the coefficients of friction of the brake pads has a significant impact on the magnitude of the braking forces and the stability of the vehicle during braking. One of the reasons for this may be the poor quality of the pad material or a violation of operating conditions. The proposed improved technique for determining the coefficients of sliding friction makes it possible to obtain more accurate values through the use of an analog-to-digital converter, reducing the influence of the accuracy of measuring instruments and the human factor.

Introduction. During the overhaul of the pipeline to remove the soil under the pipe, a trench tool is currently used. The new technology of excavation of soil under the pipeline proposed by the authors, which provides for the use of replaceable milling working equipment for a hydraulic excavator, makes it possible to increase the speed of repair work. The purpose of the article is a theoretical study of the process of interaction between the structural elements of milling equipment and the developed soil.Methods and materials. Based on the basic provisions of the theory of interaction of the working bodies of earthmoving machines with the soil, a mathematical model of the work of the milling working equipment of a hydraulic excavator was created. It makes possible to get the dependence of the resistance forces arising on the cutters of the working equipment, on its design parameters and the physical and mechanical properties of the soil.Results. According to the results of the analysis of the obtained dependence of the torque on the cutting angle and the angular speed of rotation of the milling head, it was found that the greatest influence on the torque required to overcome the forces of soil resistance and the drive of the working body is exerted by the angular speed of rotation of the milling head. The minimum value of the torque in the study area 50 N·m is observed at the point where the cutting angle of the soil is 45º, and the angular speed of rotation of the milling head is 4 rad/sec. The maximum torque 215 N·m was recorded at a cutting angle of 65º and a milling head speed of 10 rad/sec.Сonclusions. According to the results of the theoretical study of the process of cutting soil with the help of the milling working equipment of the excavator, the torque of the hydraulic motor necessary to rotate the milling head was established. The results of the theoretical studies carried out are recommended to be used to calculate the design and operating parameters in the design and creation of an experimental sample of milling working equipment.