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

proportions of constituent materials for the control concrete with a target strength of 20N/mm 2 at 28 days. The water-cement ratio was fixed at 0.5 for all the concrete mixes. The plastic PET aggregate was incorporated as substitute to the natural coarse aggregate at 10%, 20% and 30% levels. Table 1 shows the mix design of the relative proportion of each of the constituent materials in concrete production. c) Test specimens The batching method of the constituent materials employed was by weight. For the concrete workability, slump test was carried out on the fresh concrete in accordance to BS EN 12350-2: 2019. The total number of thirty-six (36) cubes of 150 mm x 150 mm and thirty-six (36) beams of 100 mm x 100 mm x 500 mm were casted. Nine (9) cubes and nine (9)beams were used for control (that is concrete of 0% of PET) while the remaining twenty-seven (27) cubes and (27) beams contain plastic PET aggregates at 10%, 20% and 30% respectively. The cubes and beams were cured in water for 7, 14 and 28 days. At the end of each curing ages, specimens were removed from the curing tank and surface dried. The bulk density, compressive strength and Flexural strength of concrete containing plastic PET aggregates and that of control (0% of PET) was determined. Universal Testing Machine (UTM) was employed for the compressive and flexural tests on the concrete specimens in compliance to BS EN 12390-3: 2019 and BS EN 12390-5: 2019. Concrete cubes were oven dried for 72 hours at 110 o c. It was removed and allowed to cool for a day. Afterwards, the cubes were weighed and recorded. Then, it was immersed in water for 30 hours. The weight was measured and recorded after expiration of 30 hours. The water absorption was determined in accordance to BS 1881-122: 2011. Table 1: Mix Proportion of Cement, Fine and Coarse aggregate and PET for Cubes % Mix of PET Cement (kg/m 3 ) Fine Aggregate (Sand) (kg/m 3 ) Coarse Aggregate (kg/m 3 ) Plastic PET Aggregate (kg/m 3 ) Water-cement ratio 0% 359.84 719.67 1439.01 0.00 0.50 10% 359.84 719.67 1295.11 143.90 0.50 20% 359.84 719.67 1151.21 287.80 0.50 30% 359.84 719.67 1007.31 431.70 0.50 III. R esults and D iscussion Figure 1 and 2depicts the particle size distribution for fine and plastic PET aggregates respectively. The fine aggregate used for this experimental study was uniformly graded soil because the coefficient of uniformity, C U is 3.33 and which is less than 6 as specified by BS 812-103-1. Also, the Plastic PET aggregate used for this research work was uniformly graded aggregate because the coefficient of uniformity, C U is 3.15, and which is less than 4as specified by BS 812-103-1.As shown in Table 2, the physical properties of plastic PET aggregate indicates that it is a lightweight material. Plastic PET aggregate has lower specific gravity, aggregate impact value, aggregate crushing value and coefficient of gradation compared to natural coarse aggregate. Also, zero water absorption was obtained for plastic PET aggregate. 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 45 ( H ) © 2021 Global Journals Version I