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The research is devoted to the analysis of available and widely used conventional measures to ensure reliable operation of the in-situ reinforced concrete structures and their compliance with legal requirements. It requires using one of the research trends of the Samara school of material sciences developed by the authors some time ago. Several stages of the work have been distinguished during the process of defining methodological foundations for effective non-destructive methods. The first stage concerned the proper mathematical apparatus of the concrete deterioration under various types of external effects. The second stage is important for determining the composition of basic physical and mechanical characteristics. Finally, the third stage is the period when the most reliable existing non-destructive methods are identified and investigation on new techniques is carried out. Thus, the combination of the A.A. Griffiths energy theory and the kinetic theory of S.N. Zhurkov has led to the formation of the mathematical apparatus that is able to simulate conditions of external effects. Testing effective methods for the concrete quality control developed by authors of this paper has been performed at the construction site. The conditions under study are characterized by a large number of ambiguous factors influencing the quantitative indicators of quality control criteria.

The results of a study of oriented blends prepared by the method of successive synthesis of polypropylene and polyethylene with ZIEOLER-NATTA catalysts are presented. It is shown that the strong interaction of polypropylene and polyethylene allows to orient and maintain the oriented state of the polyethylene melt under static conditions for a long period of time. The partially oriented polyethylene melt is in liquid-crystalline state and crystallizes with extended chains. Die Struktur orientierter Mischungen von Polypropylen und Polyethylen, die mittels kombinierter in-situ-Polymerisation erlialten wurdenDie Ergebnisse einer Untersuchung orientierter Mischungen, die durch successive Syntliese von Polypropylen und Polyethylen mit ZIEGLER-NATTA-Katalysatoren hergestellt wurden, werden dargestellt. Es wird gezeigt, dafi wegen der starken Wechselwirkung zwischen Polypropylen und Polyethylen die Polyethylenschmelze orientiert werden kann und unter statischen Bedingungen der orientierte Zustand uber langere Zeit erhalten hleibt. Die partiell orieotierte Polyethylenschmelze liegt in einem flussig-kristallinen Zustand vor und kristallisiert mit gestreckten Ketten. IIccneaosanue cmpykmypu opuenmuposannbax tio~noauyuii nonunponuaena u nonuamunena, nojzyuennb&x nojzu-aepu3ayuonnac.w coeMeu+enue.w

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Abstract. This paper presents the physical phenomenon of concrete fracture process by static uniaxial compression. The analysis of strength characteristics of concrete is carried out using fracture mechanics technology, and what is more, the actual operating conditions of structures are evaluated. The expediency of using energy approach and kinetic theory is given to consider material fracture processes with a large number of defects.