Assessment of Shredded Waste Poly-Ethylene Terephthalate (PET) Bottles Usage as Coarse Aggregate in Lightweight SHA Based Concrete Composite

Abstract

In this research report, the use of shredded waste Poly-ethylene Terephthalate (PET) bottle flakes as a lightweight aggregate in concrete was examined. Investigation was carried out on two groups of concrete samples, one made with only granite as coarse aggregate (control) and second made with PET and granite aggregate together as replacement for coarse aggregate. The PET replaced the granite coarse aggregate a varying percentage of 0%, 5%, 10% and 15%. Additionally, Sorghum Husk Ash (SHA) was also used as the replacement of cement on mass basis at the replacement ratio of 10% to reduce the amount of cement used and provide savings. The water–binder (w/b) ratio used in the mixtures were 0.55. The size of shredded PET flakes used in the preparation of concrete mixtures were between 1 and 4 mm. The results of the laboratory study and testing carried out showed that concrete comprising only granite aggregate, concrete containing PET and granite aggregate, and concrete modified with SHA as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET as aggregate in the production of structural lightweight concrete. The use of shredded waste PET due to its low unit weight reduces the unit weight of concrete which results in a reduction in the self-weight of a structural concrete member of a building. Reduction in the dead weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependent on the dead-weight. Furthermore, it was also concluded that the use of industrial and agricultural wastes such as PET flakes and SHA in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.