Global Journal of Science Frontier Research, H: Environment & Earth Science, Volume 21 Issue 6

Figure 3: Slump at various percentage content of plastic as fine aggregate b) Effect of plastic PET aggregate on concrete bulk density Figure 4 presents the results of bulk density against percentage of plastic PET aggregate. From the results, it can be seen that the bulk density of concrete decreases as the percentage of plastic PET aggregates increases. Concrete with 0% of plastic PET aggregate has the highest bulk density with a value of 2785kg/m 3 . When 10% plastic PET aggregate was added to concrete matrix, there was 4% reduction in density and the decrement increased to about 22% when 30% of natural coarse aggregate was substituted with plastic PET aggregate. Figure 4: Bulk Density of Plastic PET Aggregate Concrete c) Effect of plastic PET aggregate on concrete compressive strength Figure 5 depicts the compressive strength result of the Plastic PET aggregate concrete. The result shows that the concrete strength increases as the curing ages increases and decrease with the incorporation of plastic PET aggregate in concrete matrix. Reduction in compressive strength associated with concrete containing plastic PET aggregate increases as the content of plastic PET aggregate increases. At 28 days, the compressive strength values trends decreased by 25%, 47% and 53% for concrete containing 10%, 20% and 30% of plastic PET aggregate respectively. The decrement of the compressive strength values as the plastic PET aggregates increases is as a result of the deficient bonding of the plastic PET aggregates and the cement paste, due to the smooth surface of the plastic PET aggregate. Also, plastic PET aggregate has low water absorption and which makes excess water in the concrete. After hydration, the excess water gets evaporated and which creates voids in the concrete and weak region around the aggregates in the concrete. 0 20 40 60 80 100 120 140 160 180 0 10 20 30 Slump Height (mm) % Mix of PET 0 500 1000 1500 2000 2500 3000 0% 10% 20% 30% Bulk Density Kg/m 3 % contents of plastic PET aggregate Experimental Study on Effect of Plastic Waste as Coarse Aggregate on Concrete Properties © 2021 Global Journals 1 Global Journal of Science Frontier Research Volume XXI Issue VI Year 2021 48 ( H ) Version I