The possibility of creating centrifuged products of an annular cross section with a variotropic structure due to the introduction of a porous aggregate is considered. Various methods of introducing coarse aggregate have been studied in order to increase the uniformity of the physicomechanical properties of centrifuged products. The study examines the effect of various types of fiber fibers on the physicomechanical properties of centrifuged concrete. The results of physical and mechanical tests of fiber-reinforced concrete showed that the greatest effect on compressive strength is achieved with the introduction of a metal fiber into the composition. At the same time, shrinkage deformations are lower by 20% in the composition with basalt fiber as compared with the control fiber. Studied recipe-technological techniques have proven their effectiveness and can be successfully applied in construction practice.

Keywords: centrifuged concrete, fiber, fiber concrete, coarse aggregate, porous aggregate, variotropic structure

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