Environmental and Cost Advantages of Using Polyethylene Terephthalate Fibre Reinforced Concrete with Fly Ash as a Partial Cement Replacement

Abstract

Solid waste disposal is an alarming problem in most African countries. Plastic wastes like Polyethylene Terephthalate (PET) bottles and powdered wastes like fly ash are severely persisting environmental hazards. They are brutally polluting the water bodies, landfills, as well as the atmosphere. The construction industry has been working towards 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 common waste materials that can be used. 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. From a purely engineering point of view, the research results indicate that the utilization and incorporation of PET and fly ash wastes in the construction industry are a viable solution to make concrete quality better. This article presents, beyond the engineering properties and experimental works, the economic and environmental advantages of the addition of these waste materials to the conventional concrete mixture. The addition of PET bottle fibres and fly ash resulted in positive cost implications providing a production cost reduction of 19% over the conventional concrete mixture. The removal of these materials from the environment also showed reduction of the emission of toxic elements to landfills and water bodies that put human, animal and plant lives in danger.

Effects of hybrid polyethylene terephthalate fibre and fly ash on mechanical properties of concrete

“…The mixture containing 15% had the lowest flexural strength at all fibre percentages due to the lower workability in comparison to the mixtures containing higher fly ash content. This trend agrees with study by Singh et al (2020) [22] and Kassa et al (2019) [37] who reported a higher flexural strength at high fly ash content and low fibre reinforcement content.…”

“…The results obtained for all levels of fly ash addition show decreased workability with increase in the fibre loading percentage. This conclusion has been reached in previous studies [32][33][34][35][36][37]. Adding incremental fibres into the concrete mixture enhances the internal friction between the concrete ingredients leading to reduced workability.…”

Properties of Concrete Produced using Surface Modified Polyethylene Terephthalate Fibres

“…In addition, Borg et al (2016) [10] noted a 0.5% to 8.5% strength reduction that on the addition of PET fibres in concrete due to the low elastic modulus of plastic fibres resulting in poor composite action [54], findings which have been supported by other researchers [55]. However, some studies show a slight improvement of compressive strength at 0.5% [44,50] and 1% [56] fibre dosage. It is worthwhile to note that in most of the studies that report an increase in compressive strength, short, smooth fibres were used, and hence fair compaction was achieved.…”

The Effect of 0.8% Polyethylene Terephthalate Plastic Waste Substitution on the Flexural Strength on K-175 Concrete

“…In recent years, the construction industry has endeavored to solve environmental problems such as improperly disposed solid waste [8] where construction is one of the most complex jobs [9] so the need to recycle PET plastic to reduce these impacts by utilizing PET plastic as a mixture for concrete. By replacing or adding PET plastic into concrete is an innovation that can help to minimize the use of natural resources since concrete is one of the main materials in the construction world that is flexible, strong, and cost effective.…”