Presented and theoretically justified ways of improving the technology of centrifugation, to increase the uniformity of the concrete structure in the cross section, for example, by way of separate introduction of the components of concrete, the essence of which in the manufacture of spun goods consists in the introduction into the molding unit prior to the stage of compaction of coarse aggregate. The results of physical and mechanical tests of centrifuged concrete, showing that the layer-by-layer introduction of the concrete mixture components by the first method leads to an increase in the compressive strength in all layers of centrifuged concrete
Keywords: concrete, centrifugation, uniformity of structure, layer-by-layer introduction of components, compaction, water absorption at capillary suction, strength
In the article the problems of the technology of aerated concrete products of non-autoclaved hardening are considered and the literature data concerning the study of the influence of various factors on manufacturing technology are analyzed. The results of experimental studies devoted to the study of the role of additives of various types in the formation of aerocrete structure are presented. The influence of three factors was investigated: the type of surfactant introduced into the aerated concrete mix; presence of caustic soda additive; the consumption of aluminum powder on the process of structure formation and the properties of non-autoclaved aerated concrete. The obtained data made it possible to take a detergent powder as a surfactant in further experiments. It has been experimentally confirmed that exclusion of caustic soda from the composition of the aerated concrete mix leads to a decrease in alkalinity, and accordingly the gas release reaction proceeds much more slowly, which leads to an increase in the density of aerated concrete, the appearance of defects on the surface of products, and a significant increase in rejects. The optimal content of aluminum powder in the composition of aerated concrete is determined, which corresponds to grade PAP-1 - 5.75 g.
Keywords: Non-autoclaved aerated concrete, additive, surfactant, caustic soda, aluminum powder, gasifier, gassing