Investigation of rubber concrete on the basis of model of the spesific area of fine aggregate

Abstract

Based on the microscopic analysis of a large amount of rubber cement mortar, a mathematical model was established to qualitatively analyze the specific surface area of the rubber powder-sand mixed with fine aggregate. On the basis of the mechanisms of the influence of the methods of mixing the rubber powder, the size of the particles (rubber powders with a particle size of 20 mesh, 60 mesh, 80 mesh and 120 mesh were used - only 4 species, for testing the resistance of the concrete to the compression), etc., on the specific surface of the adhesion of the fine aggregate with rubber powder, the scientific explanation of the logical differences existing in the process of previous studies of rubber concrete has been given, the in-depth study of the influence of methods and mixing parameters, particle sizes and other factors on the resistance of concrete to compression has been carried out. The results show that the negative effect of replacing a fine aggregate of concrete with the same volume of rubber powder on the strength of concrete is much less than the negative impact on the strength of concrete rubber powder mixed with concrete. The size of particles in 60 mesh is a turning point, because the strength of the concrete for compression in the process of reducing the diameter initially decreases, and then increases. The main reason lies in the fact that the specific surface of the mutual contact of rubber particles in concrete is changing. In this paper, with the help of a large number of experimental studies, on the basis of the method of "model of determination of concrete surface area", which uses the coefficient of contact between the rubber mixture and the fine aggregate, an additional study and a deep study of mechanisms of influence on rubber concrete have been carried out