Small-Strain Shear Modulus and Damping Ratio of Sand-Rubber and Gravel-Rubber Mixtures

Abstract

This study examines the small-strain dynamic properties of mixtures composed of sandy and gravelly soils with granulated tire rubber in terms of shear modulus (G O ), and damping ratio in shear (D min ). Torsional resonant column tests are performed on dry, dense specimens of soil-rubber mixtures in a range of soil to rubber particles size 5:1-1:10 and rubber content from 0 to 35% by mixture weight. The experimental results indicate that the response of the mixtures is significantly affected by the content of rubber and the relative size of rubber to soil particles. Concering the small-strain shear modulus, an equivalent void ratio is introduced that considers the volume of rubber particles as part of the total volume of voids.Based on a comprehensive set of test results a series of equations were developed that can be used to evaluate the shear modulus and damping ratio at small shear strain levels if the confining pressure, the content of rubber by mixture weight, the grain size of soil and rubber particles, and the dynamic and physical properties of the intact soil are known.

New Formulations for Dynamic Behavior of Sand-Waste Tire Mixtures in a Small Range of Strain Amplitudes

“…A similar behavior, this time regarding the stiffness and damping ratio, was observed by Pamukcu and Akbulut [15]. Feng and Sutter [11], and Anastasiadis et al [33] reported that when the waste tire content was increased in a given waste tire and sand mixture, this resulted in a decrease of stiffness and an increase of damping ratio of the mixture. Anastasiadis et al [33] also showed that these changes in the properties of the mixture occurred in a close-to-linear fashion when the waste tire ratio allowed to be changed in the range of medium to high strain level.…”

“…Feng and Sutter [11], and Anastasiadis et al [33] reported that when the waste tire content was increased in a given waste tire and sand mixture, this resulted in a decrease of stiffness and an increase of damping ratio of the mixture. Anastasiadis et al [33] also showed that these changes in the properties of the mixture occurred in a close-to-linear fashion when the waste tire ratio allowed to be changed in the range of medium to high strain level. Later studies done on the waste tire mixtures regarding the influence of confinement time have suggested analytical relationships between shear modulus and damping ratio of the mixtures at various strain levels [34,35].…”

Experimental study on behavior of soil-waste tire mixtures

“…Some ranges of D r =D s have been reported in previous pieces of research such as D r =D s 0:25 [14], D r =D s 0:8 1:1 [15,16], D r =D s 4 [17], D r =D s 5 [18], D r =D s 10 [19,20], D r =D s 20 [7,10,21], D r =D s 100 [6], D r =D s >> 100 [4,8,9].…”

Small-Strain Stiffness and Damping of Loess in China

“…Table 5 As shown in Figure 8, it can be observed that D min of loess decreases linearly as confining stress increases in double logarithm coordinates. In comparison to the data of D min of sand published in [20,21], loess possesses higher values of D min under the same confining pressure. However, the data of D min of loess are much lower than that of cohesive soils with higher PI published in [19].…”

“…LZL-6-U/R specimens, the difference of G 0 between undisturbed and reconstituted specimens is big, while the values of G 0 between the undisturbed and reconstituted specimen are very close in saturated state. (b) Effect of confining pressure The general trends of the effect of the mean effective confining stress σ′ m on the smallstrain damping ratio D min of Lanzhou loess are illustrated in Figure 8, where the representative experimental results of D min for sand and cohesive soils [19,20,21] are included in the same figure as well. Table 5 As shown in Figure 8, it can be observed that D min of loess decreases linearly as confining stress increases in double logarithm coordinates.…”