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

Figure 5: Compressive strength of Plastic PET Aggregate Concrete d) Effect of plastic PET aggregate on concrete flexural strength Figure 6 presents the result of flexural strength of the Plastic PET aggregate concrete. It can be observed that the flexural strength increases as the curing ages increases. From the results, there was reduction in flexural strength of concrete with plastic PET aggregate compare to the control concrete. The strength trends declined as the percentage of plastic PET aggregate increases in the concrete mixture. In comparison with the control concrete, significant drop in flexural strength of 38%, 43% and 51% were obtained for concrete matrix containing 10%, 20% and 30% plastic PET aggregate respectively. Similar to compressive strength, the reduction in strength can be adjudged to be as a result of ineffective cohesion between the plastic PET aggregate and the cement paste due to the smooth surface of the plastic PET aggregate. Also, excess water in the concrete due to hydrophobic characteristic of plastic PET aggregate, and upon evaporation of the excess water, voids were created. The voids magnified as the content of plastic PET aggregate increase. The decrement of the flexural strength values as the PET aggregate increases is as a result of the weakness property inherent in the PET. 0 5 10 15 20 25 0% 10% 20% 30% Compressive strength (N/mm2) % Contents of Plastic PET Aggregate Strength 7 days Strength 14 days Strength 28 days Experimental Study on Effect of Plastic Waste as Coarse Aggregate on Concrete Properties 1 Global Journal of Science Frontier Research Volume XXI Issue VI Year 2021 49 ( H ) © 2021 Global Journals Version I