Use of Recycled Rubber as a Sustainable Alternative for Subgrade Improvement

Abstract

This study explored the enhancement of silty soil strength through the incorporation of granular rubber derived from sports field waste. The methodology involved performing laboratory tests following ASTM and AASHTO standards. The soil analyzed, classified as A-76(38) under both the SUCS and AASHTO systems, consists of medium plasticity organic clays and low plasticity organic silty clays. Initially, the soil exhibited a low CBR (California Bearing Ratio) of 12.8%, making it unsuitable as subgrade or base material. However, the addition of granular rubber resulted in a progressive increase in CBR values: with 1% rubber, the CBR rose to 13.42%; with 2%, it reached 14.37%; with 3%, it improved to 15.66%; and with 4%, it increased to 16.94%. These results demonstrate that granular rubber significantly enhances the soil’s strength, improving its suitability as a subgrade material. The study concludes that the incorporation of granular rubber is an effective and sustainable method for stabilizing silty soils, significantly boosting their bearing capacity. Furthermore, this approach offers an ecological benefit by contributing to the recycling of rubber waste, which would otherwise contribute to environmental pollution. In addition to its technical advantages, the use of recycled rubber promotes environmental sustainability, offering a cost-effective and eco-friendly solution for improving subgrade materials in construction projects. This research, therefore, presents an innovative method for enhancing soil performance while addressing waste management and sustainability challenges.