Pembuangan limbah padat merupakan masalah yang mengkhawatirkan di sebagian besar Limbah Lingkungan negara Afrika. Limbah plastik seperti botol Polyethylene Terephthalate (PET) dan Limbah Lingkungan bubuk seperti fly ash sangat berbahaya bagi lingkungan. Mereka secara brutal mencemari badan air, tempat pembuangan sampah, serta atmosfer. Industri konstruksi telah berupaya meningkatkan kualitas beton dengan mengembangkan metode alternatif seperti penggantian sebagian semen dengan elemen pozzolan yang berbeda serta menggunakan bahan limbah berserat. Fly ash dan serat botol PET adalah dua bahan limbah umum yang dapat digunakan. Artikel ini merupakan bagian dari penelitian yang mempelajari pengaruh kombinasi penambahan serat botol PET dan fly ash (sebagai pengganti sebagian semen) terhadap kinerja struktur beton. Dari sudut pandang rekayasa murni, hasil penelitian menunjukkan bahwa pemanfaatan dan penggabungan limbah PET dan fly ash dalam industri konstruksi adalah solusi yang layak untuk membuat kualitas beton menjadi lebih baik. Artikel ini menyajikan, di luar sifat teknik dan pekerjaan eksperimental, keuntungan ekonomi dan lingkungan dari penambahan bahan limbah ini ke dalam campuran beton konvensional. Penambahan serat botol PET dan fly ash menghasilkan implikasi biaya positif yang memberikan pengurangan biaya produksi sebesar 19% dibandingkan campuran beton konvensional. Penghapusan bahan-bahan ini dari lingkungan juga menunjukkan pengurangan emisi unsur-unsur beracun ke tempat pembuangan sampah dan badan air yang membahayakan kehidupan manusia, hewan dan tumbuhan.
Solid waste disposal is an alarming environmental problem in most African countries. Plastic wastes like Polyethylene Terephthalate (PET) bottles and powdered wastes like fly ash are severely persisting environmental challenges. They are obnoxiously polluting the water bodies, landfills, as well as the atmosphere. This in turn destroys human, animal and plant lives. Recently studies are being done regarding using waste materials in concrete mixes both to improve its quality as well as to benefit the environment. The construction industry has been working towards minimizing the cement usage and improving concrete quality by developing alternative methods like partial cement replacement with different pozzolanic elements as well as using waste fibrous materials. Fly ash and PET bottle fibres are two of the common waste materials that are currently polluting the environment. This article is a part of a research that studied the combined effects of the addition of PET bottle fibres and fly ash (as a partial cement replacement) on the structural performance of concrete. The study investigated the effects of the addition of PET bottles and fly ash on the engineering properties and flexural performance of concrete. PET bottles with an aspect ratio of 50 (100 mm length and 2 mm width) and fly ash were added to the concrete mix at different percentages and optimized as per the experimental work results. The optimized percentages of PET bottle fibres and fly ash are 1.5% and 27.5% by weight of concrete respectively [1] and [2]. From a purely engineering point of view, these results indicate that the utilization and incorporation of PET and fly ash wastes for the improvement of concrete quality are a move in the right direction and are highly recommended. However, other considerations like cost and environmental advantages should be assessed before the materials are used widely.
The environmental and economic advantages of waste minimization and recycling are undeniable as both the environment and the construction industry benefit in terms of pollution and cost reduction respectively. A study by [3] looked into the effects of recycling waste materials (glass, plastic and demolished concrete) and using them in a concrete mix. Alongside the engineering properties, the results of the study showed that there was a significant reduction in cost of waste disposal and construction expenses. Another study by [4] also studied the early age strength development of concrete with the addition of Activator Blast Furnace Slag. The results of this study revealed that the development of early age strength of concrete contributed to the reduction of construction period. This in turn had an economic advantage. The experimental results of compressive strength and sorptivity of PET fibre reinforced concrete were given by [5]. Fibres used were made from plastic bottle wastes which are non-biodegradable. The study presented that the addition of waste materials reduced the cost of the plastic fibre reinforced concrete while at the same time resolving the problem of solid waste disposal. It was reported by [6] that the partial cement replacement of concrete using fly ash as a replacing material reduced construction and production costs. The study also underscored that concrete modified with fly ash was more cost effective compared to the conventional ordinary Portland cement concrete.
The other significant benefit of modifying concrete with waste materials is reducing the risks the environment is facing. PET bottles are one of the major non-biodegradable plastic wastes that are considered to be dangerous for the environment. Fly ash again is a by-product of burning coal for energy generation. Because of the chemical it consists, it negatively affects soil, plants, atmosphere and the environment in general if not disposed properly. As this study is proposing to use these products for construction, it is definitely contributing to the benefit of saving the environment from the undesirable effects it is facing.
This article presents, beyond the engineering properties and experimental works, the combined economic and environmental advantages of the addition of PET bottle fibres and fly ash to the conventional concrete mixture. By doing so, it presents the necessary information for further researchers as well as individuals or companies that might want to use these materials in concrete production.
