By centrifuging it is possible to manufacture a wide range of building structures and products from reinforced concrete. Such products have several advantages, being relevant in modern construction, however, it requires careful compliance and quality control of the process. The frost resistance of concrete is one of the main indicators characterizing the durability of such building structures as reinforced concrete pillars of power transmission lines and contact network. The analysis of the literature and a series of experimental studies in the laboratory. The influence of the technology of manufacturing products from heavy concrete on the indicator of their cold resistance has been identified and determined.

Keywords: Racks of power transmission poles, racks of supports of the contact network, centrifugation, vibrating, frost resistance, heterogeneity of concrete, variotropy

The scientific interest, which is represented by research for concretes differing in strength characteristics, is substantiated. A series of large-scale experimental studies has been carried out to establish the nature of the change in the properties of heavy concrete manufactured by various methods, depending on the reinforcement by different types of dispersed fibers. At this stage of the study, in order to systematize the accumulated experimental data, the authors molded and examined products made of concrete of class B35, manufactured by vibration and centrifugation, with subsequent reduction to uniformity for the convenience of an analytical comparison of the results obtained. The compressive strength and tensile strength, as well as their increments, depending on the type of reinforcing fiber-polypropylene, basalt or steel fiber, were studied. The influence on the properties of the investigated concrete of class B35 on the combination of various prescription and technological factors has been established.

Keywords: centrifuged concrete, vibrated concrete, thin-walled reinforced concrete products, fiber reinforcement, polypropylene fiber, basalt fiber, steel fiber, compressive strength, tensile strength

The article is devoted to the study of the problem of determining the mechanical properties of vibrating centrifuged concrete with a combined aggregate and fibrous additive, which was basalt fiber. Experimentally obtained data on the optimal consumption of disperse fiber. The dependence of the strength properties of concrete with a combined aggregate on the amount of fiber additive added is graphically presented. Also graphically shows the increase in the speed of the passage of an ultrasonic wave in the body of concrete when determining the prismatic strength. It was found that the presence of porous particles in a concrete mixture facilitates the directed distribution of mineral fibers along the section of the concrete ring. This, in turn, leads to an increase in the fracture toughness of the material. The conclusion is made that the joint introduction of porous and fibrous additives into the concrete mix determines the production (at the same cement costs) of high-strength concretes with an increased crack resistance, as evidenced by the data on the displacement of the boundaries of microcracks formation in the direction of their increase.

Keywords: structures and products of annular section, centrifuged concrete, vibrocentrifuging, mechanical properties of vibrating centrifuged concrete, combined aggregate, fiber additive, basalt fiber, prismatic strength

The methods of directed formation of the variational structure of concrete products and structures are considered in the article. The experience of Russian scientists in the issues of obtaining articles of different density over the section has been studied. The problems of the technology of obtaining articles of different density along the section are considered, the main principles of shaping the variational pore structure of aerated concrete for monolithic enclosing structures, the optimal schemes for forming two-layer wall products from concrete of various densities, forming a structure with a double skeleton - mineral and polymeric - by sintering the polystyrene grains, the formation of variational structure of magnesian foam concrete, which involves sequential laying of foam masses with various average, perspectivity of the use of reinforced concrete constructions of a variational structure.

Keywords: Variational structure, concrete products and structures, reinforced concrete, aerated concrete, foam concrete, expanded clay concrete, density, fire resistance