Sustainable mixtures of TDA and Class A gravel

Abstract

Stockpiling or landfilling discarded tires poses major problems for the environment. In order to address these problems, several methods are currently employed to reuse discarded tires. One of these methods, which is gaining popularity, is to shred discarded tires into tire derived aggregates (TDA) and use them in civil engineering purposes such as backfill material for embankments or foundations. Despite the recent popularity of TDA, the experimental research to identify its geotechnical properties is limited or non-existent. Furthermore, most of the research done was either with small size TDA particles, to accommodate the readily available small-scale triaxial machines, or used direct shear apparatus which has limitations such as predefined failure surface and limited control over confinement pressure. In this study, the physical properties of five different TDA-gravel mixtures were evaluated using a large-scale triaxial machine. The TDA used in this study was the same size TDA used in civil engineering projects. All the tests were conducted according to ASTM standards. Finally, the results of deviatoric stress and volumetric strain vs axial strain for each mixture was reported and discussed.