Investigation of flexural behaviour and environmental benefits of PET reinforced concrete slabs

This study investigates the structural behavior and flexural performance of concrete slabs incorporating recycled polyethylene terephthalate (PET) at dosages of 200 kg/m 3 and 300 kg/m 3 as a partial replacement for fine aggregate in the mixture. Eight slab specimens were cast and tested, including normal concrete (NC), PET-modified concrete, and reinforced concrete slabs, with thicknesses of 10 cm and 15 cm. The experimental program involved flexural load testing to determine the first crack load, ultimate failure load, deflection, and crack patterns. The results revealed that increasing PET content improved ductility and first crack resistance, with the PET (300 kg/m 3 ) slabs exhibiting the highest deflection capacity and more distributed, narrower cracks compared to normal concrete. Although PET addition reduced compressive strength, especially at higher dosages, it enhanced flexural toughness. Reinforced concrete slabs demonstrated the highest load-bearing capacity and deflection, confirming their superior structural performance. The study highlights that PET inclusion can contribute positively to crack control and sustainability by recycling plastic waste into structural elements. Incorporating recycled PET into concrete not only enhances structural performance but also supports environmental sustainability by reducing plastic waste, conserving natural resources, and lowering the environmental footprint of construction. Overall, PET-modified concrete presents a viable, eco-friendly solution for improving the flexural behavior of slabs, particularly in applications with limited or no reinforcement.