Effects of Waste Polyethylene Terephthalate as a Partial Replacement of Normal Coarse Aggregate on Fresh and Hardened Properties of Concretes

In this thesis, the influences of waste Polyethylene Terephthalate (WPET) fragments are studied on self-compacting concrete (SCC) fresh, physical, and mechanical properties. The substitution levels of coarse aggregates with waste PET aggregates (WPET) were 5, 10, 15, and 20 % by volume. In addition, silica fume and superplasticizer (Glenium 27) were added to the SCC mixes by 10% weight of cement and 1.75 % weight of binder respectively. L-box, V-funnel, and slump flow tests were utilized to study the mixtures workability. After assessing the physical (workability tests, weight), mechanical (σs, σc, and flexural toughness), and durability (plastic degradation at 100 and 200 °C temperatures, and UPV), the outcomes reveal that it is possible to use recycled waste PET particles as aggregates up to 20 % to produce self-compacting concrete. On the one hand, adding waste PET in SCC has negative effects on the properties of SCC, decrease in compressive strength, splitting tensile strength, flexural strength, workability and UPV. Nevertheless, the compensation of this strength loss and workability could be done by adding pozzolanic materials (silica fume and fly ash) and superplasticizers (Glenium 27). On the other hand, the use of waste PET particles as coarse aggregates has positive effects as well, when it increases the toughness of SCC and makes it more deformable, reduces the self-weight of concrete owing to its low weight, and reduces the pollution of nature.