Mechanical Behavior of Clayey Soil Reinforced with Recycled Tire Rubber Using Chips and Fibers

The volume of discarded tires continues to increase each year, becoming a major topic of concern for society. Motivated by this environmental issue, this experimental study aims to evaluate the mechanical behavior and the feasibility of distinct contents (5, 10 and 15% by dry weight of soil) of recycled tire rubber used as chips and fibers for clayey soil reinforcement. Standard Proctor compaction and consolidated-drained triaxial tests under effective stresses of 50, 100 and 150 kPa were accomplished. Regardless of size, 5% rubber addition resulted in similar maximum dry density values, while optimum moisture content is influenced by the specific surface area. Overall, both particle sizes improved the mechanical behavior of natural soil, in which fiber reinforcement leads to superior interfacial bonding. The elastic behavior of clayey soil was enhanced by the residue, wherein the recycled tire rubber incorporation is more efficient for low confining stresses. Notwithstanding the equally satisfactory enhancements obtained by 5% chips and 10% fibers, cohesive intercept was affected by the interaction between rubber size and clayey particles. Even though soil-fiber rubber mixture tends to be a more promising technique in fine soil due to higher incorporation content, both reinforcing agents proved to be a technical and a socio-environmental solution to the problems associated with residues disposal and natural resources exploration.

Automated summary

The increase in discarded tires is a major concern for society. This study evaluates the mechanical behavior and feasibility of using recycled tire rubber for reinforcing clayey soil. The results show that the addition of recycled tire rubber improves the mechanical behavior of the soil, and fiber reinforcement has a superior effect on interfacial bonding.