Deformation Characteristics of Rubber Waste Powder–Clay Mixtures

Abstract

With the increasing accumulation of rubber waste, the potential reuse of rubber fillers offers a promising solution to enhance the engineering properties of low-plasticity soils while promoting environmental sustainability. In this study, the effect of rubber waste powders (RWPs) on the consolidation and deformation properties of low-plasticity clay soil (CS) was investigated using a fully automated consolidation testing procedure for clay–rubber mixtures. The study involved adding 2% up to 30% RWPs to Tehran clay, and various parameters were evaluated through consolidation, compaction, and uniaxial strength tests. The results revealed that the consolidation volume of the mixture differed from that of the CS due to the elastic nature of the rubber wastes (RWs). To achieve higher precision, a new equation was proposed to determine the void ratio, along with modified e-log p’ curves for the clay–rubber mixture. Furthermore, the addition of RWPs to the CS resulted in moderated free swelling of the soil while enhancing ductility, compression index (Cc), swelling index (Cs), and recompression index (Cr). However, it was observed that the strength and modulus of elasticity of the mixture decreased with the increase in rubber content. Considering the variations in geotechnical parameters with different rubber contents, the appropriate rubber content can be selected based on specific applications in soil and rubber mixtures, considering the required geotechnical parameters. This study highlights the potential applications of RWPs as a material in civil and geotechnical engineering projects, providing valuable insights for sustainable and eco-friendly engineering practices.