Bulletin of Prydniprovs'ka State Academy of Civil Engeneering and Architecture

10-21

Authors: Bolshakov V. I., Dr. Sc. (Tech.), Prof.; Drozhevska G. V., Postgraduate; Uzlov О. V., Cand. Sc. (Tech)., Assoc.Prof.; Puchiko V A. B., Researcher.

Problem statement. World economy suffers great annual losses due to corrosion deterioration of structures and vehicles. In some countries, losses from corrosion reach several percent of GDP. Development of new materials with increased corrosion resistance is highly relevant in the present time. Application of lacquer coatings do not provide adequate protection from corrosion in the event of abrasive contact of cargo with the protected material (freight wagons for the transport of bulk cargo). Purpose. Conduct the study of corrosion resistance of the new material developed for car building. Compare the results with the corrosion resistance of mass used in car building steel 09G2D. Conclusion Comparative studies have shown that the corrosion resistance of the perspective steel type 20ATYU is 10% higher compared to steel 09G2D. It was shown prospects of introduction of new economical-alloy structural steel.

32-41

Authors: Savytskyi N. V., Dr. Sc. (Tech.), Prof.; Storozhuk N. A., Dr. Sc. (Tech.), Prof.

Problem statement. Currently, the problem of efficient use of different types of soils whose properties are improved by cementitious materials and other chemicals for the arrangements of road and airfield carpets, is practically solved. However, when using local soil for the soil blocks production, there are many outstanding questions concerning the technology of their production, there is no theoretical justification of high quality soil blocks production as the wall material. It must be assumed that the strength and other properties of soil blocks depend on such factors as the soil grading and mineral composition, quantity, composition and activity of added binder, molding humidity of mixture, degree of the soil preliminary grinding and the quality of components mixing, method and compacting mode, the mode and period of hardening products. Various additives may have also significant influence. Depending on the combination of these factors, the properties of soil blocks may vary within wide limits. This work is devoted to a partial solution of these problematic issues. Particularly large amount of work using soil cement as a base or road surface is done in the United States. The annual volume of work using this material reaches 80 million m2. Soil cement is used in England, France, Poland, Germany, Romania, Hungary, Czech Republic. Here the main idea of using different methods to strengthen the soil is the use of local soils as a source of cheap raw materials, as a result of providing the appropriate processing to obtain high-grade substitutes of stone materials [3]. Particular emphasis needs to be placed on the work of Popov N. A., Skramtaev B. G., Higerovich N. I. regarding manufacturing techniques and the use of wall materials from soil-cement mixture [10; 11; 14]. These works contain recommendations on the choice of soil for soul blocks, production technology of these products. In the paper [6: 8], there are given existing experience of the construction of buildings of soil blocks made of cement-soil mixture, equipment for the production of such products, some of their properties are investigated. However, in our opinion, the composition of cement-soil mixture, forming modes, providing production of high strength products with allowable density of wall materials is insufficiently substantiated in these papers. Objective. Develop scientific and technical bases for the production of high-quality products using local cement and soil. Run the appropriate experimental studies to optimize the cement-soil mixture (soil-concrete), water consumption, soil blocks forming mode. Conclusions. Scientific and technical bases for the production of high quality blocks of soil using cement and local soils are developed. It was established that for any method of manufacture of such products there should be the principle of active influence on the change of colloid-chemical properties of the used soil that determines the nature and kinetics of the interaction of soil with cementitious materials and, consequently, the quality of the soil blocks. It was defined a rational part of the cement-soil mixture, water consumption, amount of pressure, which provide sufficient strength of soil-concrete at the required density as a wall material.

48-69

Authors: Khmara L. A., Dr. Sc. (Tech.), Prof.

In article scientific support on research, calculation, creation, a choice and use of construction and road machines, technical development of the author and his pupils is presented, the main scientific directions on improvement of construction equipment are presented.

76-83

Authors: Derevianko V. N., Dr. Sc. (Tech.), Prof.; Maksimenko А. А., Cand. Sc. (Tech.).; Begun A. I., Cand. Sc. (Tech.), Assoc. Prof.; Gryshko H. M., Cand. Sc. (Tech.), Senior Lecturer.

Problem statement. Magnesia cement hydration runs very slowly, because its grains are covered with Mg(OH)2 coating, preventing the water access to MgO. It has been also known, that periclase and magnesia cements having burned grains can be gauged with solutions of various salts, thereby the setting time and the strength properties are changing [5; 6]. Purpose. Creation of fast-hardening and solid structure of magnesia stone by activating MgO with electrolyte salt solutions. The effects of MgO hydration in the electrolyte-salt solutions - MgCl2 and MgSО4 was shown. Conclusion. For the formation of magnesium stone with fast-hardening and solid structure was determined that it is necessary to apply to the method of activating MgO by electrolyte salts, and select a silica-containing component out of by-products with a surface area of grains more than 10,000 cm²/g for the formation of waterproof magnesium silicate hydrate. Samples hydrated in MgCl2 solutions of different concentrations exhibit two endothermic effects of the water of crystallization evolved at 160 and 240°C. The endothermic effect of magnesium hydroxide decomposition is shifted to 380°C. At 10 and 15 % MgCl2 concentrations, besides the above mentioned effects, at 415, 500, 520°C there are observed endothermic effects, associated with the decomposition of small amounts of magnesium oxyhydrochloride at such concentrations. It has been established that at low solution concentrations (≈ 5 %) magnesium hydroxide forms solid solutions with them. According to the data of the thermal gravimetric and chemical analyzes, the solid Mg(OH)2 solution, obtained by the hydration of MgO in 5 % MgCl2 and MgSO4 solutions, has the following limiting composition: [Mg(OH)1,88∙Cl0,22]∙0,20H2O and [Mg(OH)1,86∙ (SО4)0,07]∙0,23H2O. When mixing cement by MgO solution of low concentration less 1,5 mol/l (13% or 1,1 g/sm) by end-product in stone structure is Mg(OH)2.

98-104

Authors: Ragimov S. Yu., Cand. Sc. (Tech.), Assoc.Prof.

Problem statement. The data of the Ministry of Health and the International Labour Organization indicate that mortality from injuries and occupational diseases in the world ranked third after cardiovascular diseases and cancer. As of 2014 in Ukraine, more than 3,4 million persons are working in conditions that do not meet sanitary standards. Especially difficult are the conditions at work associated with the release or use of heat sources. Workers at the enterprises of the construction industry (production of bricks, glass, polymers) are exposed to influence of high temper-ature. Purpose Justification of the use of means for measuring thermal radiation in the workplace. Conclusion. It was found that the existing instruments of domestic and foreign production does not allow us to in-vestigate working conditions at the workplace of hot productions due to a significant range of thermal radiation from 50 to 24,000 W/m2, which makes a significant error in the measurement. For the first time, it found that the measurement of both small and large heat flows low limit and highly sensitive sensors must be used, thus, dosing time of heat flow access. It was disclosed regularities of changes in the reflectivity of the material type and length of the radiation spectrum. Based on conducted researches of the excess thermal radiation intensity at workplaces of hot productions and steady temperature of the heating surface, it was identified distribution of maximum wavelength of the infrared radiation, supported by law of Golitsyn-Vin. It was proposed rapid method for assessing the reflectivity of materials, which allows to receive information at an early stage of research and development of protective equipment from infrared radiation. Stand for research reflection and transmittance of materials in response to changing the angle of incidence of the radiation, surface condition and its polarizing ability is improved, the error in this case, does not exceed 5 to 7%. New approach in the creation of effective protective measures, taking into account the spectral component of the infrared radiation is suggested. On the basis of the first conducted researches, this measurement technique allows to estimate the impact on the workplace, not only primary, but also secondary sources of radiation. Based on the analysis of existing domestic sensors to measure the intensity of the heat flows, the choice of sensors and study their characteristics, taking into account their influence on the temperature component, is made.

111-121

Authors: Mlodetskiy V. R., Dr. Sc. (Tech.), Prof.

Problem statement. Information flows in organizational management structures are caused by a number of factors such as efficiency of administrative staff, level of uncertainty of the current state of control object, required level of precision (reliability) to achieve the end result - control objectives. The effectiveness of control system depends on its ability to maintain a certain state of the system within a range of uncertainty. It is an objective reality, because the deterministic condition is theoretically possible, but not practical. Therefore, by examining in more detail the information flows in organization management on the basis of the theory of information, we can identify common ways of increasing the organization controllability, determine the dependence of uncertainty level of the state of the control object on the control mode of that object. Analysis of recent research. Item "information" is closely connected with such important term as "entropy", which is primary in relation to information. Uncertainty is considered as a measure of information. [7] Uncertainty is understood as the problem of deciding under conditions in which certain solutions lead to different results, depending on the probability of influence factors [14]. The entropy in information theory, according to the statement of K. Shennon, serves as a measure of uncertainty of the condition or behavior of the system under these conditions. Comparing given, it can be noted that a measure of uncertainty serves entropy, in turn "information is communication, connection, which reduces uncertainty". Thus, none of these categories is not separate from each other. Leon Brillouin in the book "Scientific Uncertainty and Information" - M.: Mir. 1966. pp. 25 noted that only the "related information" will represent negentropy. In relation to the management process, the concept of "related infor-mation" could be understood as a message that has been accepted by subject of management and administrative action were taken in relation to it, which led to the improvement of the control system. The paper [6] contains an axiom "change of intrasystem information occurs so that the growth of negative entropy (measure of order) system reduces the entropy (measure of disorder) in the system". Object and purpose. In these studies, it was discussed in detail the processes in the chain - the entropy, infor-mation, negentropy, but the balance of the system is possible when there is a feedback of negative entropy to the entropy, and this is one of the goals of the work, the second objective is to determine the system control mode according to the set level of uncertainty of the control object. Conclusions. Stable operation of the open-driven organizational structure is provided by dynamic balance be-tween accumulated therein entropy and negentropy, the balance between them is done through the exchange of infor-mation and negainformation. Rate of entropy growth in the system, level of required accuracy of determining the value of monitored parame-ters, which determine the current state of the system, affects the level of control of the organization.

129-135

Authors: Nevgomonnyi G. U., Cand.,Sc.,(Tech).,Prof.; Mukhanova V. V., Master student.

Raising of problem. World's natural resources are: coal - 909 064 billion t..; оil – 12 580 milliard barrels; Natural gas - 173trillion m3. Considering the factor, that more than 2.3 billion tons of coal, 30 187milliard m3 of oil and gas is consumed for a year, it will be more than enough of natural resources for the following years: coal for 200 years, oil - 42 years, gas - up to 65 years [1; 3; 5]. Now there is the global economic downturn, so it is necessary to find alternative natural resources. An effective way of solving this problem is energy saving measures inculcating and state support use, based on managing alternative renewable energy sources in the nearest future. The usage of renewable energy sources will increase the energy of the world, and also will provide environmental cleanliness, social and economic development. Nowadays, the energy of the sun is one of the most perspective among renewable energy sources that can be collected by solar panels. Purpose. Analysis the principles shaping of active energy complex-houses using solar energy. Conclusion. The most efficient in terms of minimizing heat loss is a circular shape. It has the smallest perimeter and that’s why building with circular shape in the plan will have the smallest area enclosing parts. Another advantage of the circular shape of the building -if the building’s facade is covered with solar batteries, the process of electrical energy generation will be much efficient. Considering a great step in the solar panels production in a short period of time, we can assume that the common way of their usage will change.