The Influence of Rubber Crumbs on the Energy Absorbing Property of Waste Mixtures

Abstract

The practical application of waste materials such as steel furnace slag (SFS) and coal wash (CW) is becoming more prevalent in civil engineering. While the addition of rubber crumbs (RC) derived from waste tyres can influence the geotechnical properties of the mixtures of SFS and CW significantly, especially the energy absorbing property. In this paper, the energy absorbing property of the SFS+CW+RC mixtures under static loading has been evaluated by the strain energy density. As expected, the energy absorbing capacity of the waste mixture increases with the addition of RC.To further illustrate the influence of rubber crumbs on the energy absorbing property of the waste mixtures, particle degradation has also be examined after finishing the triaxial tests. It has been found that the addition of RC can significantly reduce the particle breakage of the waste mixtures. Therefore, with high energy absorbing property, the SFS+CW+RC mixtures can be further extended to dynamic loading projects, such as railway capping layer.ABSTRACT: The practical application of waste materials such as steel furnace slag (SFS) and coal wash (CW) is becoming more prevalent in civil engineering. While the addition of rubber crumbs (RC) derived from waste tyres can influence the geotechnical properties of the mixtures of SFS and CW significantly, especially the energy absorbing property. In this paper, the energy absorbing property of the SFS+CW+RC mixtures under static loading has been evaluated by the strain energy density. As expected, the energy absorbing capacity of the waste mixture increases with the addition of RC. To further illustrate the influence of rubber crumbs on the energy absorbing property of the waste mixtures, particle degradation has also be examined after finishing the triaxial tests. It has been found that the addition of RC can significantly reduce the particle breakage of the waste mixtures. Therefore, with high energy absorbing property, the SFS+CW+RC mixtures can be further extended to dynamic loading projects, such as railway capping layer.

Predicted Behavior of Saturated Granular Waste Blended with Rubber Crumbs

“…The geotechnical properties of SFS+CW+RC mixtures under static loading have already been investigated earlier by Indraratna et al (2018), Qi et al (2018a), and Qi et al (2018b). The test results indicate that incorporating RC into SFS+CW blends can further reduce particle breakage in CW and swelling of SFS.…”

Application of geoinclusions for sustainable rail infrastructure under increased axle loads and higher speeds

“…5). Generally, the energy absorbed by the energy-absorbing layer (EAL) would be converted to permanent deformation and/or dissipated by Test results for SFS + CW + RC matrix (after [15] and [56]): a strain energy density varying with effective confining pressure and b breakage index varying with RC content heat and particle breakage. The dissipated energy represented by the area of the hysteresis loop is due to: (a) the recoverable deformation of particles, (b) the friction of particles and (c) particle breakage [34,35,68].…”

Use of Geogrids and Recycled Rubber in Railroad Infrastructure for Enhanced Performance

“…These impact forces can likewise be generated at transition zones involving abrupt variations of vertical track stiffness, such as at the approaches to tunnels, bridge or viaduct and level crossings, or where there is a sudden change from conventional ballast to slab track intensifying ballast breakage and adversely affecting track stability [11][12][13][14][15]. One potential method of enhancing the substructure capacity to withstand the large cyclic and impact loads induced by fast-moving heavy-haul trains is to improve the performance of the ballast layer using plastic (e.g., geogrids) and rubber inclusions (e.g., rubber mat, tire cell, and rubber crumbs) [2,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

“…The high damping properties of rubber materials have made them a promising inclusion for rail track as to enhance the energy absorbing characteristics of rail tracks, as well as reduce noise, vibration, ballast degradation and impact damage to track components [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Since these rubber materials can be made from end-of-life tires, they are environmentally friendly and economically attractive, promoting optimism and exploration into the potential use of rubber materials in rail foundations.…”

“…Since these rubber materials can be made from end-of-life tires, they are environmentally friendly and economically attractive, promoting optimism and exploration into the potential use of rubber materials in rail foundations. Several types of rubber inclusions are used in rail foundations: (i) rail pads (i.e., placed between the rail and sleeper interfaces), (ii) under sleeper pads (USP) installed at the interfaces of the sleeper and ballast, (iii) under ballast mats (UBM) placed beneath the ballast, (iv) rubber crumbs or shreds mixed with ballast, (v) tire cells installed in the capping layer, and (vi) a synthetic-energy-absorbing-layer (SEAL), i.e., a mixture of rubber crumbs and other waste materials [4,[19][20][21][22][23][24][25][26]. It was found that the under ballast mats can reduce overall ballast degradation by around 25-45%, and reduce the vertical plastic strain by around 10-20% and the lateral strain of ballast by around 5-10% [20].…”