Dynamic behavior of sand-rubber mixtures based on hollow cylinder tests

Dynamic Shear Modulus and Damping Ratio of Sand–Rubber Mixtures under Large Strain Range

“…Figure 12 indicates that, taking the case of SRP2 as an example, the damping ratio initially increases with increasing rubber volume content. This also can be observed in the results of Ehsani et al [ 42 ], and is similar to the results of Sarajpoor et al [ 7 ] and Senetakis et al [ 21 ] as previously mentioned. Note that the damping ratio exhibits a strong dependence on the rubber particle size, and shows an optimal value at a specific rubber volume content.…”

“…Additionally, note that the dynamic shear moduli of the mixture specimens decrease slightly at higher rubber volume contents. Feng et al [ 34 ] and Sarajpoor et al [ 7 ] have reported similar observations.…”

“…At small strain levels less than the critical strain, the inherent damping provided by the rubber particles contributes more to energy dissipation than other factors, and therefore the sand–rubber mixtures exhibit greater damping than the pure sand. At high strain levels greater than the critical strain, intergranular friction contributes more to energy dissipation than the rubber particles [ 7 ]. The effects of rubber volume content, rubber particle size, and confining pressure on damping ratio can be summarized as follows: An increase in the rubber volume content causes some sand particles in the specimens to be replaced by rubber particles, increasing the weak contacts between rubber and sand, in turn decreasing the intergranular friction and leading to a decrease in the damping ratio.…”

“…This excessive accumulation threatens both environmental and human health [ 5 , 6 ]. However, the increasing volume of discarded rubber tires has garnered interest in developing new methods for reusing these materials [ 7 , 8 , 9 ], and thus motivated researchers to characterize the general geotechnical properties of sand–rubber mixtures [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”

“…They can be summarized as follows: Pistolas et al [ 28 ] clearly showed that shear strain has a significant influence on the damping ratio. Sarajpoor et al [ 7 ] reported that at shear strain amplitudes less than about 0.1%, an increase in rubber volume content results in a higher damping ratio, while at shear strain amplitudes greater than about 0.1%, the opposite trend is observed. While Senetakis et al [ 21 ] showed similar conclusions, it should be noted that Okur et al [ 29 ] obtained contrary findings using resonant column tests, indicating that under shear strain amplitudes less than about 5 × 10 −2 %, an increase in rubber volume content leads to a lower damping ratio, with the reverse being true under greater shear strains.…”