Improvement of the Geotechnical Properties of Sandy Soil Using Shredded Polyethylene Terephthalate (PET) Wastes

The increased use and production of plastic in developing countries is a growing concern, as the technology of their waste management infrastructure may not be developing at an appropriate rate to deal with the increasing levels of plastic waste. This paper presents the results of the investigation of the engineering behaviour of Ogbese river sand (specific gravity-2.63, fine gravel content-2.72%, sand content-97.28%, AASHTO classification-A-3(0)) stabilized with shredded polyethylene terephthalate (PET) water bottle waste and Portland cement. The goal of this research is the beneficial reuse of the enormous discarded PET plastic waste generated in Nigeria in civil engineering works. The PET water bottles were shredded into strip sizes ranging from 0.3cm × 0.3cm to 0.7cm × 0.7cm. The soil was mixed with PET strips of 0.4%, 0.8%, 1.2%, 1.6%, and 2.0% by weight of soil and 3% cement by same weight of soil. The cement acted as a binder for sand-PET mixtures. Sand-PET-cement mixtures can be used for road pavement base and sub-base course that requires subsurface drainage and as lightweight backfill for retaining structures, due to its favourable strength and permeability characteristics. However, the long term durability and sustainability of soils stabilized with shredded PET wastes in different geologic/hydrogeologic conditions should be investigated before using them in practice.