Browsing by Author "Luwalaga, John Groover."

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    Analysing the Behaviour of Soil Reinforced with Polyethylene Terephthalate (PET) Plastic Waste
    (Stellenbosch : Stellenbosch University, 2016-03) Luwalaga, John Groover.; De Wet, Marius; Vijay, P. V.; Stellenbosch University. Faculty of Engineering. Dept of Civil Engineering.
    ENGLISH ABSTRACT: Environmental issue effects like natural resource depletion, climatic change and global warming have significantly influenced the innovations in material science and technology with the aim of attaining sustainable materials to avert calamities. Conservation and sustainability of quality natural materials in the civil engineering field is a challenge currently due to their scarcity brought about by increased population, rapid development of cities and continued depletion of such materials. On the other hand, currently there is a boom in the plastic industry as most of the sectors like agriculture, automotive, education, government, health, marketing and advertising, transportation, to mention but a few use plastic products. Due to the wear and tear of the plastic products there is a challenge in handling the non-biodegradable plastic waste by the solid waste management field. This research has been conducted to mitigate the challenges faced by the civil engineering field and the solid waste management field by analysing sand-PET (Polyethylene Terephthalate) plastic waste composite. The research was conducted at Stellenbosch University (SUN), using materials like PET plastic waste flakes from the Kaytech factory and sand of medium dense, clean quartz uniformly graded with round shaped particles which is predominant in Western Cape region, South Africa. Furthermore, the aim of this research was achieved through the experimental work which included particle size distribution testing, compaction testing, California Bearing Ratio (CBR) testing, and direct shear box testing. Sand was reinforced with randomly mixed PET plastic waste flakes of different varying percentages of 12.5%, 22.5% and 32.5%, and tests were performed on unreinforced sand and sand-PET plastic waste composite specimens. It was established that sand reinforced with 22.5% of PET plastic waste flakes gave an optimum value of PET plastic waste giving a maximum percentage increase in friction angle of 15.32%, hence the highest shear strength with an angle of friction equal to 44.4o.Furthermore, the optimum maximum dry density of 1547kg/m3 resulted into a maximumfriction angle of 44.4o. It was concluded that the appropriate percentage of PET plastic wasteto use while reinforcing sandy soil used in this study is 22.5%. Therefore, it was established that reinforcing soil with 22.5% PET plastic waste can improve its bearing capacity and CBR. The soil-22.5% PET plastic waste composite can be applicable in civil engineering applications like as material for foundation bearing strata, light road sub-base or subgrade, and as backfill materials for foundations and retaining walls. Additionally, the study has established that reinforcing soil with 22.5% PET plastic waste is sustainable, hence mitigating the social, economic and environmental impacts by reducing need for natural resources, no land filling of PET plastic waste, and increased utilisation of poor quality construction soils like sand. Furthermore, calculations where done and found out that reinforcing sand with 22.5% reduced the width of the foundation by 3% which made it more economical compared to unreinforced sand.