Dynamic Properties of Granulated Rubber/Sand Mixtures

Abstract

Processed waste tires mixed with soils are applicable in lightweight fills for slopes, retaining walls, and embankments that may be subjected to seismic loads. Rubber's high damping capacity permits consideration of granulated rubber/soil mixtures as part of a damping system to reduce vibration. The dynamic properties of granulated rubber/soil mixtures are essential for the design of such systems. This research investigates the shear modulus and damping ratio of granulated rubber/sand mixtures using a torsional resonant column. Specimens were constructed using different percentages of granulated tire rubber and Ottawa sand at several different percentages. The maximum shear modulus and minimum damping ratio are presented with the percentage of granulated rubber. It is shown that reference strain can be used to normalize the shear modulus into a less scattered band for granulated rubber/sand mixtures. The normalized shear modulus reduction for 50% granulated rubber (by volumme) is close to a typical saturated cohesive soil. Empirical estimation of maximum shear modulus of soil/rubber mixtures can be achieved by treating the volume of rubber as voids.

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.…”

“…Conversely, mixtures with higher waste material ratios were observed to possess a relatively elastic response. As Feng and Sutter [11] also reported in their investigations, damping response in a given waste tire -sand mixture may be resulting from (i) the friction between each particle or (ii) the deformation of each particle. Particles of sand are known to be stiff, which explains why they dissipate small amounts of energy during deformation.…”

“…These discarded materials are sometimes used in reinforcement of weak soil, slope stabilization or as a backfill in retaining structures [1][2][3][4][5][6][7][8]. Soil mixed with waste tires have been shown to possess a higher compressibility, low void ratio, high friction angle, and high attenuation [9][10][11][12][13][14][15]. Finding the damping ratio and shear modulus of waste tire mixtures will be the scope of interest of this paper, and in accordance with that, behavior of sand-waste tire mixtures will be studied and two different approaches, namely SR and GP, for modeling the mentioned properties of waste tires will be presented.…”

“…The researches done until very recently on the topic included investigation of basic soil properties such as compaction, compressibility, permeability, shear strength, modulus of elasticity, and Poisson's ratio. These studies, however, did not provide a comprehensive overview of the dynamic properties of soils in relation with the waste tire ratio [11,[25][26][27][28]. Owing to their elastic properties, mixtures composed of sand and waste tires could prove a useful element in energy dissipation, and therefore in seismic energy absorption in underground tunnels [29][30][31].…”

Seismic isolation using granulated tire–soil mixtures for less‐developed regions: experimental validation

“…On the other hand, the reuse of shredded tires has great potential in geotechnical engineering programs, where rubber-soil mixtures (RSMs) are often used in lightweight backfill, highway embankments, soil reinforcement, and retaining walls [4]. Such large-scale geotechnical applications of recycled rubber can consume tremendous numbers of waste tires.…”