Sustainable building solutions: A comprehensive study on PCPET waste-induced bricks

Abstract

An exponential increase in plastic production and a substantial rise in plastic waste have forced scholars to seek a sustainable and groundbreaking solution that recycles/reuses plastic waste to minimize its adverse environmental impacts upon disposal. Having been used by various sectors, production of construction material from plastic waste has received more interest. Numerous studies have proven that shredded polyethylene terephthalate (PET) plastic bottles constitute a valuable construction material where plastic waste management/recycling procedures are not effective. The goal of this study lies in factors such as strengthening construction material, reducing carbon emissions in atmosphere and minimizing overall costs. Manufacturing plastic M-sand bricks, and integrating post-consumer PET (PCPET) from single-use plastic water bottles into M-Sand is the main focus of our research. This work used two types of PCPET wastes (washed and unwashed) with different mix proportions of plastic and M-sand, such as 1:1, 1:2 and 2:1 for brick production. The bricks manufactured are tested for durability through compression, water absorption, efflorescence, and dimensional stability, and subsequently, Energy Dispersive X-ray Analysis (EDX) and scanning electron microscopy (SEM) for morphological assessment. By the conducted experiential results, it is evident that the design mixes M3 and M8 guarantee appreciable strength that is 2–1.5 times of other mix designs. The M3 design mix with one part washed PCPET and two parts M-sand has exhibited superior performance, with a compressive strength of 40.29 N/mm², minimal water absorption, and observed homogeneity in SEM. In addition, post-demolition sustainability is addressed by integrating recycled brick aggregate with M-sand, showing optimal results for design mix M8, including a compressive strength of 40.54 N/mm², favorable water absorption, and positive SEM findings. EDX confirmed zero carbon elements in the produced bricks. These findings prove the strength of our research on the sustainable recycling of waste thermoplastics within the circular economy, presenting a promising solution to environmental and economic challenges.