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Study of rheological properties of concrete mixtures based on modified cement systems in order to determine process parameters. Methodology. To study structural-mechanical properties of modified concrete mixtures of different consistency at their horizontal vibrating displacement an oscillatory viscometer was designed. Results. The optimization of the process of vibration displacement of concrete mixtures with the specification of parameters of vibration impacts taking into account structural-mechanical properties of the mixture is performed. It has been established that the viscosity of the modified cement system of the concrete mixture is a variable quantity, which depends on the parameters of the vibration impacts. Scientific novelty. The mechanism of interaction of the modified concrete mixture with the form and the table vibrator during its vibration compaction is determined. On the basis of this, a model of concrete laying process control is proposed, that allows to predict the ability to form a dense concrete structure. Practical significance. Disclosed physical nature of the process of vibrating displacement of modified concrete mixtures using the principles of physical-chemical mechanics of concrete allows reasonably choose the best options for vibration impacts.

Purpose. Improving the technology of concretes on the basis of secondary mineral resources (waste foundry sand of metallurgical and machine-building industry, ash-and-slag mixes of thermal power plants). Methodology. Generally accepted standard methods in the study of the basic properties of raw materials, concrete mixes and concretes are used in the work. The samples were moulded using specially made laboratory vacuum equipment. Findings. The study results on the main properties of concretes on the basis of secondary mineral resources confirmed the effectiveness of vibrovacuum technology. For example, the strength of ash-and-slag vacuum concrete is on average higher than the strength of vibrocompacted concrete from a mobile concrete mix by 610 MPa or by 60100% (depending on the cement consumption). Also, high-quality concretes with moderate cement consumption for various types of construction are obtained on the basis of waste foundry sand. Originality. Scientific and technical bases of the technology of vibrovacuum concrete on the basis of waste foundry sand and ash-and-slag mixes were developed. Practical value. Through the development of the technology of vibrovacuum products based on secondary mineral resources concrete, high-quality concretes (increased strength, frost resistance, etc.) were obtained for road and other types of construction. This technology allows applying the existing technological equipment without fundamental design changes, carrying out immediate dismantling of moulded products, which significantly reduces the metal consumption of the technology.

Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings) based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic-viscous-plastic bodies. The system of canonical equations consists of the equations for concrete strength, absolute volume, concrete mix consistency as well as the equation for optimal concrete saturation with aggregates while minimizing cement content. The joint solution of these four equations related to composition allows determining for the materials the concrete composition of required strength, concrete workability with minimum cement content. The procedure for calculation of hydraulic concrete composition according to the physico-analytical method consists of two parts: 1) physical, which is laboratory testing of concrete mix components in different concrete compositions; 2) analytical, which represents the calculation algorithm for concrete compositions equivalent in concrete strength and workability that comply with the specific conditions of concrete placing. Findings. To solve the problem of designing the concrete composition with the desired properties for railway structures and buildings it was proposed to use the information technology in the form of a developed computer program whose algorithm includes the physico-analytical method for hydraulic concrete composition determination. Originality. The developed concrete composition design method takes into account the basic properties of raw materials, concrete mix and concrete, which are predetermined. The distinctive feature of physico-analytical method is obtaining of a set of equivalent compositions with a certain concrete mix consistency and required concrete strength, which allows to optimize the concrete composition by any optimality criterion, depending on the operation conditions. Practical value. Using the developed method will expand its functionality when applied in the form of the composition calculation computer program for the construction and repair of surface and underwater structures. The use of physico-analytical method at production site will simultaneously solve the economic problems of construction and maintenance cost reduction, component saving and ensure obtaining the concrete with the set properties for specific operation conditions of transport engineering structures.

Purpose. To analyze the need of loans in the form they are presented today at the present stage of economic functioning. To develop a systematic group of actions in order to allow the “economic and financial” system of the country to work efficiently, irrespective of economic and financial world cataclysms. Methodology. Computer simulation model of monetary movement in the state is developed and tested. Conclusions. A retrospective analysis of the essence of theories of credit and lending rate has been made. Some aspects of interest receiving on deposits and loans from the point of view of a radically new economic model of management, which based on the "National economy high-performance theory», are considered. Using the simulation modeling the negative influence of bank interest on the national economy general development is indicated. It is proved that the main reason of the “financial and economic crisis” is the economic category of “profit”. Originality. A radically new model of banking system functioning in the country is proposed. This system allows one to create synergistic economic effect. Practical value. Implementation of the given model will provide the GDP growth for the 2–2.5 times as early as the first years. The economic effect of the introduction can bring about 1 trillion UAH.