Particle–scale interactions and energy dissipation mechanisms in sand–rubber mixtures

Abstract

Sand-rubber mixture (SRm) behaviour is affected by rubber content (RC) whilst dissipation in sands is caused by inter-particle sliding. Dissipation in SRm is as, or more significant than in sands. However, the mechanisms of dissipation in SRm are not well understood. In this study, onedimensional compression tests on sand samples with RC of 0%, 15%, 30%, 45% and 100% by mass were performed on a standard oedometer. In addition, a SRm with RC of 30% was tested on a minioedometer placed inside an X-ray scanner and 3D images of the internal structure of the material were acquired at three stages during loading and unloading. Image analysis was used to infer particle-scale measurements and provide experimental evidence to help explaining the energy dissipation mechanisms for SRm. It is postulated here that energy dissipation in these mixtures is dominated by inter-particle sliding at initial stages of loading, but once rubber particles fill the voids spaces between the sand, deformation and dissipation mechanisms are dominated by the deformation of the rubber particles.

Resonant Column Tests on Mixtures of Different Sands with Coarse Tyre Rubber Chips

“…However, when mixed with rubber, damping is induced not only by the friction between sand and rubber particles but also by the deformation of the rubber particles, cf. Fonseca et al (2019). As a result, increasing the rubber content in the mixtures leads to an increase of the damping ratio as well.…”

The effect of adding rubber crumbs on the cyclic permanent deformation of waste mixtures containing coal wash and steel furnace slag

“…mainly compressibility) of the rubber-soil mixtures (e.g. Edil and Bosscher, 1994;Rao and Dutta, 2006;Lee et al, 2007, Fonseca et al, 2019Sheikh et al, 2012). These studies show that inter-particle sliding, grain rearrangement and distortion, as well as void-filling capacity of individual rubber particles contribute as key factors to the deformation mechanisms of rubber-soil mixtures.…”

Recent Advances in Nature-Inspired Solutions for Ground Engineering (NiSE)

“…clay, nano-stabilising agent and biopolymer nuclei) through the network, where the size of the edge of the network is determined from CSD, informed by μCT [59]; b criteria, whether a base particle would move through the constriction, whether it would be trapped, and when it would be retained in the void space [59]; c an example of determining CSD as a function of 15% percentile of particle size [58] processes involve complex interactions with the grains themselves and the pore space amongst them; such interactions are practically impossible to be studied in absence of advanced imaging tools. μCT has also been used to study the interaction between rigid and soft particles in sand-rubber mixtures as a means for improving the properties/behaviour of sands [63]. Not only can the grains be visualised via processed X-ray images, but the kinematics and interactions of the grains can be quantified using software, such as the python-based Software for Practical Analysis of Materials (SPAM, [64]).…”