Suitability of using post-consumer polyethylene terephthalate wastes in cement-based hollow sandcrete blocks

In recent times, efforts are channeled towards limiting the impact of waste plastic pollution on the environment. This study examines the beneficial utilization of polyethylene terephthalate (PET) wastes, which is a non-biodegradable waste materials as a partial substitute for sand in the production of non-load bearing hollow sandcrete blocks. The physical and mechanical properties such as density and compressive strength of the hollow sandcrete blocks using PET waste as a replacement for fine aggregate at 5%, 10%, 30% and 50% were determined. Tests results show that the density of the produced sandcrete blocks decreases as the waste PET content increases. Results showed that the density varied from 1391.33 kg/m 3 for 50%PET content to 1954.54 kg/m 3 for 5%PET content, while the density of the reference sandcrete was 2002.15 kg/m 3 for 7 days. The values of densities ranged between 1453.88 kg/m 3 for PET 50% and 1851.09 kg/m 3 for PET 5% and the density of reference sandcrete was 1991.77 kg/m 3 at 28 days. The sandcrete blocks also demonstrate a similar reduction trend in compressive strength as the PET content increases. The compressive strength ranged between 1.140 N/mm 2 for 50%PET and 2.564 N/mm 2 for 5%PET content and 1.510 N/mm 2 for 50%PET to 2.991 N/mm 2 for 5%PET respectively, as the curing age increases from 7 to 28 days. The hollow sandcrete block containing an optimum 5% replacement percentage of sand with PET waste showed comparable strength to the conventional sandcrete blocks. This will help to mitigate the menace of marine plastic pollution and promote responsible consumption.