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

35-39

Authors: V. I. Bolshakov, V. Volchuk, Yu. Dubrov

To study the structure of metals and alloys and its influence on their properties are widely used traditional methods of macro- and microanalysis, X-ray, spectral, thermal and inspection (X-ray, magnetic, ultrasonic). They have their own threshold, often narrowly focused and applied directly depending on the purpose of the research object (pipe, forming rolls, metal, etc.). Currently existing mathematical models of forecasting the qualitative characteristics of metal products based only on an analysis of statistical data do not provide physical-chemical interpretation of the processes that occur during the formation of the structure or who could definitely take into account the effect of the chemical composition and other parameters of the technology. Therefore, the forecast results can not always meet the requirements. In order to obtain acceptable quality results produced by the product specifications developed by the forecast methodology should include the use of both classical and modern methods of structure evaluation. So, to determine the relationship between mechanical properties and structure elements of cast iron roll is planned to use the theory of fractals and multifractal. The proposed method is the most appropriate to quantify the majority of real structures, which the integer approximation of the figures of Euclid introduces some uncertainty, and therefore not always acceptable in practical problems of modern materials. In this regard, it is assumed conducting special experiments, the analysis of which allows to develop a qualitative evaluation of the mechanical properties of the investigated steels and cast iron. As a result of analysis of the production technology of steel and iron and research work aimed at solving the problem of evaluating the mechanical properties of the formulated problem statement of operational forecasting of these properties and the basic ways of its solution.

46-53

Authors: V. I. Bolshakov, V. N. Derevianko

Statement of the problem. In recent years, products based on gypsum binding materials is widespread, as their application allows to increase the productivity and quality of work. However, their production is constrained by lack of efficient dry additives. Domestic additives for adjusting the properties of gypsum binders are mainly in the liquid state. The use of imported additives increases the cost of products. One of the ways to obtain the dry additive is the use of polyvinyl acetate dispersion, which is widely used in liquid form to adjust the properties of cementations materials. But by the reworking to the dry condition the dispersion is aggregated. Furthermore, the additive does not have the required functional properties. The main problem of the production of dispersible polymer powders is development of the mechanism of their dispersion and film formation, and selection of regulators. So the stabilizers in the system prevent the coagulation of the emulsion (dispersion). Protective colloid provides obtaining of the dispersion powder, then is able to disperse in the water. And, finally, drying (moisture removal) leads to the film formation.

61-70

Authors: V. I. Bolshakov, T. S. Kravchunovska, S. Bronevitsky

Purpose. Systematization and formalization of organizational, technological and economic factors reflecting the specific features of the construction of affordable housing and performing substantial impact on the cost of building production and the duration of works. Methodology. Substantiation of the list of factors exercising a decisive influence on the cost and duration of construction of affordable housing, using the methods of expert estimations. Findings. It was formed the system of organizational and technological and economic factors that reflect specific features of construction of affordable housing and carry out a significant impact on the cost of such construction products and the duration of works. Originality. Further development of the system of organizational-technological and economic factors that affect the performance indicators organizational and technological decisions of the construction of affordable housing. Practical value. Implementation of scientific and practical research results in the activities of design and construction organizations in the process of organizational and technological design of affordable housing will improve the validity of decisions.

79-87

Authors: V. I. Bolshakov, G. D. Sukhomlin, V. I. Sukhomlin

It was made a search for new and more accurate orientation relations between the crystal lattice in the pearlite and bainite austenite decomposition products. Methods. It were used the methods: transmission electron microscopy, the micro-, mathematical matrix and stereographic analysis. The purpose of the research is with theoretical, numerical and experimental methods to set up to a 0.2 degree angular orientation relations between the lattices of ferrite and cementite in the austenite decomposition products in the temperature range 400 ... 700°С. Results. It was established a new, refined value for grids in the diffusion decay of γ → α + (α + θ). Practical significance. It was proposed a new oriented dependence and the corresponding double gnomonic projection with poles to planes α and θ phases, which can be used in patterns of crystallographic lattices relations studies at phase transitions, as well as the subsequent modeling of complex physical processes of structure formation in metals and binary systems.