Enhancing The Engineering Characteristics of Clayey Soil with Recycled Tire Rubber Particles

Abstract

This research examined how adding rubber granulate affected the properties of expansive soil from Shahat City, Libya. The study tested different drying techniques, curing times, and rubber concentra-tions (0% to 15%). For preparing samples to determine Atterberg limits and for compaction testing, air drying was deemed more suitable than oven drying. The soil's unconfined compressive strength was enhanced by the inclusion of rubber. A 2% rubber mixture produced the highest strength after a 3-day cure, while a 4% mixture was most effective after 7 and 14 days. This addition also transformed the soil's behaviour from brittle to ductile. Microscopic analysis revealed stronger cohesion between par-ticles at the 4% rubber level. The liquid limit rose with smaller rubber amounts but fell with larger ones. The optimum moisture content increased up to 8% rubber before declining, whereas dry density con-sistently dropped. A numerical Plaxis analysis showed some variance from the experimental findings. Furthermore, the soil's bearing capacity was enhanced and settlement reduced as additional rein-forcement layers were added, provided the vertical spacing between them was adequately small to prevent potential collapse.