Recycling of Polyethylene Terephthalate Wastes in Production of Hollow Sandcrete Blocks for Sustainable Construction

Abstract

This study investigates the suitability of crushed polyethylene terephthalate (PET) waste, which is a non-biodegradable generated waste as a substitute material for natural sand in the production of hollow sandcrete blocks for sustainable infrastructure. The physical properties of the natural sand and crushed PET aggregate materials used in the batching mixtures which include; specific gravity, water absorption, bulk density and particle size distribution were determined. While the mechanical properties; density, compressive strength, and the water absorption of the produced hollow sandcrete block samples using the granulated PET aggregate as a replacement for natural sand at 5%, 10%, 30% and 50% were studied. Results showed that the PET aggregates exhibit lower physical properties compare to natural sand. The addition of the finely granulated PET aggregates as a partial substitute for natural sand gradually reduced the density of the hollow sandcrete blocks as the replacement increases in the mix. However, the water absorption tendency of the sandcrete blocks reduces as the percentage dosages of PET aggregate increases. A similar reduction trend was noticed in the compressive strength of the produced hollow sandcrete blocks. The results showed a strength reduction from 2.564 N/mm2 to 1.140 N/mm2 for sandcrete mixes containing 5% and 50% PET, respectively, and 2.991 N/mm2 to 1.510 N/mm2 for sandcrete mixes containing 5% and 50% PET, respectively as the percentage substitution of sand with PET increases for 7 and 28 days curing age. The obtained results indicate the possibility of using granulated PET aggregate at 5% sand replacement in production of hollow sandcrete blocks of comparable strength to conventional sandcrete blocks. This will help to promote green production for sustainable infrastructure and reducing the menace of plastic pollution in line with the UN Sustainable Development Goals.