Stress-strain response of quaternary sand mixed with granulated rubber under restraint condition

The Quaternary soils, QS, are considered widespread materials found near or at the Earth's surface. Despite their engineering characteristics, they are characterised by low vibration damping. On the other hand, materials such as rubber tyre waste (TW) exhibit greater damping capacity. Such material is problematic in the surrounding environment and causes critical hazards. Mixing these materials yields composite geomaterials with distinct characteristics for varied geotechnical applications and helps address many challenges associated with them. To ensure the benefits outweigh the likely risks, systematic testing of the Quaternary Soil-Rubber Tyre Waste (QSTW) mixtures is crucial. The current study surveys the responses of QSTW mixtures under confined-restraint conditions. For laboratory specimens’ preparation, different weight fractions of the TW were mixed, in the dry condition, with the QS (0.0, 15.0, 30.0, 45.0, and 100.0%). The volume deformability, stiffness, and energy dissipation were produced from testing these specimens under zero lateral strain in dry and saturated states. The results indicate that the mixtures of QSTW suffer more deformation and become less stiff with increasing rubber inclusion. Such inclusion permits the grains' rearrangement and allows additional replacement from the solid skeleton, producing different packing. The degree of the nonlinearity of the stress-strain curves increases with higher TW, and the mixtures' response seems "rubber – like" at higher content. In contrast, the absorption and the energy dissipation of the QS augment with the TW inclusion, where the TW acts as a mini damper within the mixtures. These mixtures show high capacity for vibration-damping and thus can be applicable for various infrastructures subjected to vibrations.