Mechanical parameters of soil-rubber mixtures for sustainable geotechnical projects

The inadequate disposal of rubber waste from scrap tires is a globally recognized problem. In Brazil alone, 12.23 million tires were manufactured in the first quarter of 2024. The incorporation of this solid waste into geotechnical projects can serve to mitigate the environmental impact of its disposal. The results of the characterization, static, and dynamic tests performed on a Brazilian lateritic clayey soil and soil-rubber mixtures are presented in this study. The tests were conducted with pure soil and with soil-rubber mixtures in proportions of 2.5%, 5.0%, 7.5%, 10.0%, 12.5%, and 15.0% of rubber weight in relation to the weight of the pure soil. A novel methodology for determining the damping ratio (D) parameter directly from the top of the compacted pure soil and soil-rubber mixtures is presented. Based on this study, the rubber from shredded scrap tires can be used in applications such as compacted embankments, soil walls reinforced with geosynthetics, and seismic barriers. However, it is not recommended for use in pavement layers. The results indicated that the increase in the percentage of rubber leads to the decrease in the following parameters of the mixture: resilient modulus, shear modulus, elastic modulus and damping ratio. The cohesion of the mixture increase slightly, as the percentage of rubber increase.