A study on damping ratio of rubber concrete

In this paper, the damping ratio and the mechanical property of rubber concrete, made through partially replacing the fine aggregate in the concrete with rubber powder, have been studied. The goal of this study is to develop rubber concrete with high damping ratio to mitigate the environmental vibration transmitted via floor to the precision machinery in high-tech factories. Thus it can prevent the unwanted vibration caused by pipelines or other machines from reducing the yield rate of the precision production. The first part of this study is to discuss the effect of mixing-ratio on the mechanical properties, such as the compression strength , of the concrete cylinder with different rubber admixture, including #10 and #40 rubber powders. Secondly, to determine the damping ratio of the cantilever beam specimen made of rubber concrete by the impulse experiments. The parameters of different admixture, mixing-ratio, and age effect were investigated. The results revealed that the admixture of rubber powder is useful in raising the damping ratio of the concrete. For the rubber admixture added not exceeding 7.5%, the damping ratio increased 156% at most with adding #10 rubber powder, 194% with adding #40 rubber powder, respectively. Simultaneously, however, the compression strength of the rubber concrete reduced 10-27% with #10 rubber powder added, and reduced 13-41% with #40 rubber powder added, respectively.