ABSTRACT
The annual usage of plastic worldwide is at a global rise, leading to a major detrimental concern due to plastic’s low biodegradability and abundance in quantity. The best way to overturn these problems for benefit is to recycle the plastic wastes for better use.
In this work, we selected a few plastic waste types and used them to partially replace the naturally occurring (and costly) aggregates.
We started out with replacing the fine aggregates with 10%, 20% and 30% contents of the polystyrene and polypropylene recycled plastics ground into the fine aggregate sizes. Then, we also replaced the coarse aggregates with 10%, 20% and 30% polyvinylchloride (PVC) and High-Density polyethylene (HDPE) recycled plastics, carefully broken into coarse aggregate sizes. All the aggregates were replaced in volumes and cast into the appropriate moulds, three cubes per sample.
On observing the slump values of the samples, the control sample produced a slump value of 109mm whereas none of the partially replaced samples fell below this value. The slump values were however within the range of 125mm-170mm. The bulk density of the partially replaced samples all fell below the control sample value of 2580 Kg/m³ but no sample recorded a value below 2130kg/m³. The concrete was expected to reach a design strength of 25KN/m², however, the control sample reached the average strength of 39KN/m² with none of the partially replaced samples falling below 29KN/m² compressive strength.
Finally, we arrived at amazing results because even while some of the of the desirable qualities of the conventional concrete were reduced for the percentage replacement of plastic we carried out; the results were still within the desirable limit. Also, the recycled plastics added some desirable characteristics to the concrete such as lightweight. It can be concluded on the basis of this experiment that recycled plastic can be used in concrete application.
