Exploring the micromechanical behaviour of sand-rubber mixtures using X-ray micro-tomography

Zhuang Cheng,Wei Li,Jianfeng Wang,M.A Aguirre,L.A Pugnaloni,S Luding,R Soto

doi:10.1051/epjconf/202124911009

Zhuang Cheng, Wei Li + Show 5 more

Open Access

https://doi.org/10.1051/epjconf/202124911009

Copy DOI

Abstract

The micromechanical behaviour of sand-rubber mixtures (SRMs) under monotonic triaxial shear were investigated using X-ray micro-tomography. The localisation of sand particle rotations that occurred in a pure sand sample under shear was inhibited in the sand mixed with 30% rubber grains by mass. Meanwhile, the SRMs exhibited an evolution of sand-sand contact coordination number that is not negatively correlated with sample porosity, dramatically different from that was observed in pure sands. Substantially increasing anisotropy degree of sand-rubber contacts compared with minor changes of sandsand contact fabric was observed, implying the increasingly important role of sand-rubber contacts in the transmission of deviatoric loads as the shear of SRMs progressed.

Highlights

In recent years, accelerating increase of waste rubber tyres as a result of rapid rising vehicles has posed a great threat to the environment
This paper presents the use of X-ray micro-tomography to explore the micromechanical behaviour of sand-rubber mixtures (SRMs) under monotonic triaxial compression, with a focus on the fabric evolution of sand-sand contacts and sandrubber contacts as well as grain kinematics
Triaxial compression tests were performed on pure sands and SRMs with a rubber content of 30% by mass

Summary

Introduction

In recent years, accelerating increase of waste rubber tyres as a result of rapid rising vehicles has posed a great threat to the environment. Composed of two types of grains (i.e., sand grains and rubber grains) with substantially different stiffnesses, SRMs generally have more complex mechanical behaviour than pure sands. The complexity stems from the existence of multiple load-transferring mechanisms including loads transferring through sand-sand contacts, sand-rubber contacts and rubber-rubber contacts within SRMs [3,4,5,6]. This intrinsic feature of SRMs has dominated the fact that their mechanical behaviour is affected by various factors including rubber content, rubber shape and size as well as soil types. While the mechanical behaviour of SRMs have been intensively studied in recent years, the underlying particle-level mechanisms remain poorly understood because of the lack of experimental tools to investigate the grain-scale behaviour of SRMs

Methods

Results

Conclusion