Determination of the maximum dangerous width of a rail track on a reinforced concrete base with fasteners of the КБ type, taking into account all influencing factors

Railway track retention standards in Ukraine do not take into account theconstruction of the subrail base, but regulate one for all types maximum dangerous value of the trackwidth, which was changed from 1546 mm to 1548 mm without any justification of scientific researchor explanations of the effects of tolerances the width of the rail track and the wheel track, which ingeneral at that time were not fully investigated but taking into account the emergence anddevelopment of new scientific problems associated with the emergence of intensive lateral wear ofrails and ridges of locomotive and wagon wheels. The deterministic dependences of lateralimpressions of the P65 type rail thread head on the simultaneous influence of vertical and horizontalforces for the newly installed repair profiles of UZ rolling stock on the basis of previously performedexperimental and theoretical studies were investigated. The results allow at this stage of research todetermine and calculate the practical values of the maximum dangerous width of the track, in whichthe subrail base consists of reinforced concrete sleepers and separate rail fasteners, which are usedboth on conventional highways with mixed traffic and on high-speed lines UZ.The article establishes the need to take into account new factors influencing the dangerouswidth of the rail track with intermediate rail fasteners of separate type depending on the load stress of sections and new repair profiles of rolling stock, as well as wear processes of intermediate railfasteners type KБ and its elements on the appearance of elastic backlash in the lateral direction fromthe influence of the guide wheels of the rolling stock. The recommended value of the maximum widthof the rail track for areas where service or emergency braking is applied - 1550 mm, taking intoaccount that the contact of the wheel and the rail is not at a point, but on an ellipse. The establishednorm of the maximum width of a rail track allows to define economic efficiency of introduction in theconditions of operation of a track in curved sections of a track of small radii with limited use of themaximum admissible lateral wear (15 mm) of a head of a rail thread provided that the normal-forcedentry of rolling stock carts.

Мastering and modernization of physico-chemical processes of synthesis of oxide compounds with structure of pyrochlorine

Modern scientific and technological development of society, further intensification of production together with the provision of proper safety of human life and preservation of the environment necessitate the search for new solutions in the creation of new materials and technologies. The creation of effective materials for the latest and future technologies and technicaldevices is based on new scientific data on the definition and analysis of specific mechanisms of physicochemical processes that implement the desired structural and phase state of solids with the desired set of properties. In recent decades, the most effective way to control the properties of solid materials is the use of nanotechnology and nanomaterials, which have recently been increasingly used in almost all areas of new technologies. The article investigates synthesis processes, structural characteristics and structural-phase processes in multicomponent metal-ceramic oxide materials, physicochemical mechanisms ofsynthesi s of multielement oxide compounds Y2Zr2O7 with pyrochlor structure during consolidation and sintering of yttrium and zirconium oxides, structure formation -phase characteristics of materials with different chemical composition. The structural-phase evolution in the synthesis of new substances and the consolidation of compounds of the Y2O3 – ZrO2 system have been studied. Samples of oxide heat with the proportion of pyrochlorine phase Y2Zr2O7 up to 41 % were obtained. It is established that the kinetics of increasing the proportion of pyrochlorine phase in the samples indicates a desirable increase in the activity of the chemical reaction, which can be achieved by increasing the synthesis temperature to the temperatures of eutectic formation or increasing the reaction surface of powders.

Recovery of the bitumen and asphalt concrete properties with rejuvenator

The main factor in the decreasing in the quality of asphalt concrete with time is thehardening of the bituminous binder, which occurs under the influence of high environmentaltemperatures, moisture and oxygen. Considering this, one of the ways to extend the service life ofasphalt pavements isto implement procedures to prevent deterioration of the properties of bituminousbinders, which occurs due to its hardening. To solve the problem of hardening, the use of variousrejuvenators becomes widespread in road maintenance around the world. The aim of the researchwork is to analyze the effect of the domestic rejuvenator Lux «ЕD-L» on the properties of roadbitumen and asphalt concrete made with this binder. The effect of the rejuvenator on the propertiesof bitumen is evaluated in three ways: finding the influence of Lux «ЕD-L» on the properties of theoriginal bitumen; finding the ability to restore the properties of RTFOT-hardened bitumen by addingan additive to the hardened binder; finding the effect on the intensity of hardening by hardening ofbitumen, which includes the Lux «ЕD-L» additive in its composition. In addition, according to thisscheme, it is evaluating the effect of the rejuvenator on asphalt concrete mixtures, which areconditioned according to the method of AASHTO R 30-02. Based on the obtained experimental data,it is found that the modification of the RTFOT-hardened bitumen with Lux «ЕD-L» additive improvesbinder’s properties, which results in the returning of the values of standard quality indicators(penetration, softening point and breaking point temperatures) to the initial level of values quality ofbitumen before hardening. Lux «ЕD-L» additive significantly improves the adhesion properties ofbitumen (both original and aged). Evaluation of the impact of the rejuvenator on the properties ofasphalt mixtures after conditioning confirmed its effectiveness. The properties of asphalt concrete made from mixtures after conditioning, which were treated with the Lux «ЕD-L» additive, accordingto obtained quality indicators is equal to the asphalt concrete with the original bitumen. A field testof the effect of the Lux «ЕD-L» additive on the properties of the asphalt pavement is in process. Theresults of field test will be obtained after 3 and 9 months of operation of the treated road section.

Corrosion-resistant facing material with of mineral binders and assets modified by sulfur melt

The paper considers the issues of obtaining a composite material based on gypsumbinder and sulfur with high performance. Technological factorsinfluencing the hardening coefficient, water resistance and chemical resistance of gypsum products impregnated in sulfur melt have beenstudied. The regularities of impregnation of gypsum matrix with sulfur melt are established takinginto account the capillary-porous structure of gypsum stone and physical and technical properties ofsulfur. The regularities of impregnation of gypsum matrix with sulfur melt are established taking intoaccount the capillary-porous structure of gypsum stone and physical and technical properties ofsulfur. Research and consideration of mass transfer indicators during impregnation of gypsumconcrete products with sulfur melt allowed to optimize the technology. Thus, by the method ofcapillary impregnation on the original laboratory installation, the mass transfer coefficients forsulfur were measured. As a result of these studies, the dependences of the mass transfer coefficienton the temperature of the sulfur melt, the rate of heating of the melt, the concentration of the fillerand the water-solid ratio were obtained. Products made of composite material based on gypsum andsulfur have the following construction and technical characteristics: compressive strength, not lessthan 30.0 MPa; flexural strength, not less than 6.0 MPa; water resistance coefficient, not less than0.7; coefficient of corrosion resistance, not less than 0.7; wear resistance, no more than 0.3 g / cm2 .Analysis of the main construction and technical characteristics of the composite material based ongypsum and sulfur shows that the resulting composite has high strength, water and corrosionresistance to various aggressive environments. Facing tiles made of this material have highperformance characteristics and should be used in the lining of buildings of railway infrastructure,drainage systems, fertilizer storage, floors and walls of the chemical and food industries.

Review of the basic mechanisms of energy efficiency management and emissions control from ships

Increasing relevance of the problem of energy conservation and use of alternativesources of energy in connection with global and local resource crises led to the formation of adeveloped system of international standards in the field of energy management, which is aimed atregulating and disclosing the content of the principles of energy efficient processes and development.Rational policy in enterprises of various industries and the implementation of energy-savingmeasures, particularly in the maritime transport. The dynamics of implementation of projects aimedat increasing the efficiency of energy use is growing steadily at different levels and in different sectorsof industry. It is widespread in the fields of design, modernization and reconstruction of energyefficient buildings and structures, construction of industrial infrastructure elements, technologicalproduction processes. Implementation of such projects is a priority line of activity for enterprises andcompanies of various types of economic activity. Accordingly, the leading sectors of industry develop strategies to improve environmental safety and energy efficiency - ship navigation is no exception.Indeed, the process of increasing energy efficiency is achieved by reducing fuel consumption, whichwithout exception leads to a reduction in the amount of waste products discharged into theatmosphere. Therefore, the problems of energy efficiency in order to increase requirements forenvironmental safety of transport and increasing responsibility of shipowners become the centralobject of research of current theory and practice of operation of maritime transport means. Anotherurgent issue is the improvement of universal principles of energy efficiency within the framework ofindividual ship-owning companies and the development of tools for economic analysis of energyefficiency of the own fleet, search for new ways to form professional competencies of shipcrewmembers in the field of energy conservation.

Defects systematization of reinforced concrete bridges of ukrainian railways as the result of their inspection

Visual inspection is the important part of the bridges management. Many defectscan be detected that determine the traffic conditions, service life, and operation cost. Thedeterioration of bridges calls for effective methods for condition evaluation and maintenance as wellas suitable methods of their repair and recovery. This article aims defects systematization ofreinforced concrete bridges to define the effective method for recovering of their technical state. Morethan 100 reinforced concrete bridges in Ukrainian railways were inspected from 2017 to 2021.Ultrasonic pulse velocity, penetration resistance, reinforcement corrosion tests, and rebar locatingwere performed on beams, bed block, and piers of reinforced concrete bridges. It is shown that themost probable reasons of defects are natural impacts (freezing-thawing, moisturizing-drying),technogenic factors (train vibration, leakage current), and technological disadvantages(unsatisfactory production or setting). During the inspection, there are three categories of defectswere defined. The first one does not influence the train traffic (for example, deficient protectiveconcrete layer). The second one can limit the train traffic (for instance, crack width more than 0.3mm). The third category endangers the safe railway operation (such as an intense leaching of cementstone at an area more than 2 m2). It is made a proposal to match external signs of damage withreasons their appearance and methods of recovery. Three main types of repairs are used in Ukrainianrailways: torkret process, steel hooping, waterproof layer. However, the relationship between thetype of defect and the method of recovery has not been estimated before. It is important that themethods of repair and protection will be assigned according to their operation state (a disabled staterequires immediate recovery of the structures) as well as the reasons of appearance (destructiveacts). These methods must prevent a future destruction or protect of the structures.

The community heating network’s thermal condition assessment

Heat losses at the heating network’s distribution pipelines were identified for Karkivcommunity. Heat losses’ calculation is performed in view of the underground pipelines’ installationin non-accessible ducts. The heating system water temperature is accepted in line with the heatingnetwork temperature chart and according to the design outdoor temperature value for heatingpurposes. Specific heat losses in the network section’ pipelines are accepted at the level of standardvalues for the specified network laying method. The water flow rate at the heat pipeline sections isdefined as per the design heat loads from the buildings connected to the heat supply network. Theheat pipeline segment with uniform diameter is accepted as the rated section. The soil temperatureat the heat pipeline axis laying depth is accepted as 5°C. The heat losses at the structural networkelements are considered by 1.15 coefficient. The calculations are performed in view of the heatingsystem water flow rate and temperate changes along the heat pipeline length. While analyzing thethermal condition of the return pipelines of the community heating network, the changes in the heatcontent of the heating system water flow in the main direction pipeline during mixing with the waterflow from the branches of the main direction line are taken into account. Considering the averagetemperature of the coldest five days consecutively, the total energy loss in heating pipeline for a groupof buildings in Kharkov region are equivalent to 180.8kW.In view of the ambient air temperature changing over the heating period for Kharkiv cityclimate conditions and the current schedule for quality heat energy supply to the consumers controlthe annual heat losses in the community heating network pipelines were calculated. The soil temperature change at the heat pipeline installation depth during the heating period was notconsidered.Heat losses in the microdistrict network for the year are 2184 GJ. The data obtained can beused to compare options when developing a strategy for reforming the microdistrict heat supplysystem.

Justification of a rational option of development of the highspeed railway according to technical, technological and economic criteria

When a new high-speed railway is designed on the routes with the existing mixed(freight and passenger) traffic, part of the trains can be relocated from the existing railway to thenew one. This will have an additional effect of the increasing current capacity of the existing railway. A method is proposed for justification of a rational option for the development of a high-speedrail on the basis of technical, technological and economic criteria. It is proposed to solve the problemof determining the rational option for the development of a high-speed railway as the problem ofoptimal distribution of resources among the components of the railway, taking into account technical,technological and economic criteria. The result is a set of solutions consisting of options for thedevelopment of each component of the railway, which will provide the maximum systemic effect forthe railway as a whole. Each jth option of the development of the ith component of a high-speed railwaycan be described by three main indicators: the travel time of a high-speed train; capital investmentsrequired to implement this option; and the available traffic capacity of the component. Depending onthe problem being solved, each of the listed parameters can act both as a criterion and as a limitation.Depending on the purposes of the design, it is proposed to consider the problem of determiningthe rational option for the railway development either in the direct or inverse setting. In the first case,the systemic effect is expressed by an objective function that minimizes the amount of necessarycapital investments in the railway infrastructure while ensuring the stipulated travel time of a highspeed train. In the second case, the purpose is to minimize the travel time of the train withoutexceeding the specified amount of capital investment in the development of all components of therailway.The results obtained can be used to justify decisions on the use of single-track components andto determine the rational configuration of single-track lines when high-speed traffic is organized.

Cartographic analysis of the distribution of degraded lands (on the example of the Рoltava region)

Cartographic analysis can be considered as one of the means of the land monitoringsystem, in particular, by the distribution of degradation processes. The work is proposed to createfor regions of cartogram of total distribution of degraded agricultural land and cartograms offraction of agricultural lands that have undergone water and wind erosion, acidification, salinization,with indispensable drawing on these cartograms of the river network scheme. The zoning of the Poltava region is presented and analyzed in terms of the total distribution ofdegraded agricultural land, as well as separately by the particles of water, wind erosion,acidification, salinization.According to the relative distribution of degraded agricultural lands (without taking intoaccount the overlap of various types of degradation) within the Poltava region, there are 2 groups ofdistricts of increased land degradation: 1) northern (covers 7 districts – Pyriatyn, Chornukhy, Lubny,Lokhvytsia, Myrhorod, Hadiach, Zinkiv) and 2) southeastern (covers 3 districts – Kobeliaky, NoviSanzhary and Mashivka).Water erosion is inherent in districts with significant difference in heights and largest forestcover. This is primarily Dykanka, Zinkiv, Reshetylivka districts (watershed between rivers of Psel andVorskla), Lokhvytsia and Chornukhy districts (watershed between rivers of Sula and Udai) and theChutove district (watershed between rivers of Vorskla and Orel). Wind erosion covers predominantlynorthwestern, north and southeastern districts – Pyriatyn, Chornukhy, Hrebinka, Lokhvytsia,Hadiach, Mashivka, Novi Sanzhary.Cartograms of distribution of degraded land are supplemented by the river network on them.The method of their creation is described. The cartographic method is substantiated by theinterconnection of the districts of increased acidification of soils with basins of the rivers Udai andVorskla, and the districts of minimum acidification of soils – with the basin of the river Khorol.Salinization of soils of the Poltava region should be associated, obviously not with superficial,and with groundwater. In the future, it is recommended to use for a cartographic analysis of thedistribution of degraded lands additionally maps of groundwater hydroisogyps.

Сurrent state of securing the territory of Рoltava region by points of the national geodesic network

The actual problem of securing the proper functioning of the NGN of Ukraine takinginto account regional peculiarities are studied.The analysis of the state of NGN of Ukraine on the territory of Poltava region by types ofcenters, external geodetic signals, methods of determination of coordinates is carried out in the work.The general problems of functioning of NGN in the territory of Poltava region are established.It is established that in a significant amount of points there are no external geodetic signals.The centers that fix the points of the NGN are represented by more than 40 different types. The centersdiffer in design and size. Some of them are at the same time is references of leveling II category.It is proposed to plan perspectiving measures for the modernization of the NGN on the reasonof the calculation of indicator of regional compliance of the NGN with regulatory requirements forthe density of stations to secure the implementation of topographic surveys. This indicator iscalculated as the ratio of the real amount points in the newly created administrative district to thenormative amount, and is reflected as a percentage. The normative amount is determined on the basisof the area of the respective area and the normative density of stations for the suitable scale of survey.In case of provision of stations at the level of less than 100 % it is necessary to determine theamount of points required to bring the real density in accordance with the normative. Then theexisting NGN needs modernization. Such modernization can be carried out not only in the form of renewal of existing and restoration of lost points, but also through the design and fixation ofadditional points of the calculated number.The analysis of securing of the territory of Poltava region with NGN points for implementationof topographic survey in scales 1:5000, 1:10000, 1:25000 is carried out. Specific proposals toachieve one hundred percent provision of stations in the Poltava region have been developed. Anexample of a possible realization of the respective proposals is illustrated by the design scheme ofadditional stations of the 3 class, developed on the basis of the scheme of the NGN of Ukraine.