Incorporation of crushed PET as partial replacement of fine aggregate in concrete

Abstract

The increasing generation of plastic waste has become a significant environmental concern, encouraging the development of alternative reuse strategies across different productive sectors. In this context, this study investigates the use of recycled polyethylene terephthalate (PET) as a partial replacement for fine aggregate in concrete, aiming to evaluate its effects on fresh and hardened properties, as well as its potential as a sustainable material. Three concrete mixtures were produced with 0%, 5%, and 10% PET replacing natural sand, maintaining a constant base mix design. Cylindrical specimens were prepared according to current technical standards and subjected to slump tests to assess workability, as well as compressive strength tests at 7, 14, and 28 days. The results indicated that the incorporation of PET did not significantly affect the workability of the mixtures, with slump values remaining close to the reference concrete. Regarding compressive strength, the mixture containing 5% PET showed performance comparable to conventional concrete at early ages, while the 10% replacement level led to a more pronounced reduction in strength. It can be concluded that low percentages of PET can be feasibly used in non-structural applications, contributing to plastic waste reuse and reducing the demand for natural aggregates, thus supporting more sustainable construction practices.