EFFECTS OF POLYETHYLENE TEREPHTHALATE (PET) PLASTICS ON THE MECHANICAL PROPERTIES OF FLY ASH CONCRETE

Abstract

Concrete is the favored construction material for its high compressive strength and low maintenance cost. With the global interest in sustainable construction materials, continuous research is being done on alternative concrete materials. Research is geared toward the improvement of concrete properties as well as contributing to waste utilization. A study was conducted by incorporating polyethylene terephthalate plastics (PET) into fly ash concrete to investigate the effects on compressive and flexural strengths. As the addition of fly ash as a partial replacement for concrete is known to improve concrete strength, the addition of PET as a partial substitute for fine aggregates could be advantageous. A constant of 30% fly ash was used in the concrete mix proportions for test specimens, while the amount of PET introduced varied from zero to 15%. Specimens were prepared and tested following ASTM standards. It was observed that increasing the amount of PET in fly ash concrete mix also increased workability and decreased the unit weight of concrete. Compressive strength test results show that 5% to 10% PET plastic substitution increased the compressive strength of fly ash concrete. Test specimens containing 5% PET led to an increase in the flexural strength of fly ash concrete and a further increase in PET content indicated a decrease in flexural strength. The results of this study show that the inclusion of PET in fly ash concrete could lead to increased workability, a decrease in unit weight, and improved compressive and flexural strength without the use of admixtures.