High-performance concrete for industrial construction and mechanical engineering

The multicomponent composition of the raw material mixture and the heterogeneity of the structure of highly functional concretes at various scale levels make it possible to effectively control the formation of indicators of its damping properties due to prescription and technological factors. Experimental compositions included Portland cement, quartz sand, granite screening, silica, metacaolin, quartz flour, microcalcite, shrinkage compensators, hyperplasticizer and reinforcing microfiber. The hydrodynamic properties were investigated by methods of free and forced oscillations.Experimental compositions included Portland cement, quartz sand, granite screening, silica, metacaolin, quartz flour, microcalcite, shrinkage compensators, hyperplasticizer and reinforcing microfiber. The hydrodynamic properties were investigated by methods of free and forced oscillations.Experimental compositions included Portland cement, quartz sand, granite screening, silica, metacaolin, quartz flour, microcalcite, shrinkage compensators, hyperplasticizer and reinforcing microfiber. The hydrodynamic properties were investigated by methods of free and forced oscillations.A laboratory complex of vibrodynamic tests has been developed that provides automated processing of the amplitudes of bending damping vibrations of the first mode of concrete samples to calculate the dynamic modulus of elasticity and the logarithmic decrement of attenuation. The high accuracy of the results obtained made it possible to identify the nature of the influence of various prescription factors (consumption of cement, pozzolan additives, microfiber, shrinkage compensators) on the dynamic modulus of elasticity and damping of concrete. An increase in the value of concrete damping (by 1.22 times) was established with an increase in cement consumption from 300 to 734 kg/m3. The introduction of shrinkage compensators, differing in the mechanism of action, made it possible to obtain non-shrinkable injection molding compositions and favorably affects the vibrodynamic parameters correlating with the magnitude of the overall heterogeneity of the microstructure of concrete.The results of the research have been tested in the manufacture of prototypes of concrete and reinforced concrete cutting machines (small-sized milling machine), as well as laboratory testing equipment.