Valorization of Plastic Waste for Masonry Bricks Production: A Novel Construction Material for Sustainability

The number of wastes generated from PET plastic coupled with other wastes associated with manufacturing industries is running in billion metric tonnes annually. If scientific solutions are not provided, these wastes will become a fulcrum to an impending environmental disaster. The aims to avert the impending consequences of this disaster and conserve natural materials have fostered sustainable production of low-carbon embedded construction materials. With this view in mind, this investigation is channelled towards evaluating the strengths and durability of waste plastic bricks (WPB) fabricated by the valorization of scrap PET plastic and foundry sand waste. The WPB masonry bricks were fabricated using plastic to sand ratios of 10:90, 20:80, and 30:70, respectively. A series of compressive strength tests, modulus of rupture tests, apparent porosity tests, water absorption tests, salt-resistance tests were conducted to investigate the strength and durability of the WPB in conformance with the South African National Standard (SANS 227) for individual load-bearing masonry face brick unit. Compared to the clay bricks with 18 MPa what of strength, the test result revealed that the WPB rendered an average compressive strength of 35.2 MPa. Furthermore, the test result showed that the WPB recorded significant strength resistance under tension compared to the clay brick due to the ductility properties of scrap plastic waste. Also, the acid effects were significantly resisted on the surface WPBs due to the hydrophobic property of the PET waste. The stiffness of the clay bricks portrayed a brittle response, whereas WPBs benefited with high-ductility properties.