The current state of the issue of the nomenclature of centrifuged thin-walled prefabricated reinforced concrete products of the ring configuration is analyzed. The scientific interest, which is represented by the technology of fiber reinforcement for such concretes, is grounded. The actual problems for concretes produced by the centrifugation method are indicated. 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. To systematize the accumulated experimental data, at the first stage of the investigation, products of low-strength concrete, class B20, manufactured by vibration and centrifugation, were molded and investigated, followed by a reduction to uniformity. 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 effect on the properties of the investigated concrete of the B20 class is determined by the combination of various prescription and technological factors.
Keywords: centrifuged concrete, vibrated concrete, thin-walled reinforced concrete products, fiber reinforcement, polypropylene fiber, basalt fiber, steel fiber, compressive strength, tensile strength
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 influence of dropping out of kamnedrobleniya and mineral filler, included in its composition, the fine-grained characteristics of self-compacting concrete.Studies have shown the efficacy of combined use in the composition of the fine self-compacting concrete dropping out of kamnedrobleniya fractions of 2.5-5 mm, and mineral filler mixture fractions 0-2,5 mm. At the optimum dosage of the products of kamnedrobleniya and modifying additives in the composition of fine-grained mixtures ensure the required flow characteristics of the concrete mix achieved the required strength of the concrete. Mineral filler – dust component of dropping out of kamnedrobleniya allows to increase the total volume of the test binder, sufficient to fill the intergranular voids and coating grains of a filler, and contributes to water-holding capacity and the persistence of the mixture.
Keywords: kamnedrobleniya screenings, mineral filler, fine self-compacting concrete, superplasticizer, water-retaining additive, the spreadability of the mixture, keeping the mixture, the strength of concrete