Insight into the polyethylene terephthalate powder on mechanical performance and sorptivity analysis of concrete

This study investigates the impact of incorporating Polyethylene Terephthalate (PET) powder nanomaterials as a partial replacement for cement in concrete to improve water absorption and mechanical properties. The primary objective was to evaluate how these materials, when used as partial replacements for cement, affect concrete performance. The novelty was to convert the PET waste into stable nano powder materials to cover the plastic waste management from the community. The physical and chemical properties of the PET materials were characterised using Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM-EDX), Transmission Electron Microscope (TEM), Raman spectra, and X-ray Diffraction (XRD). The PT-nano material was found to be highly crystalline (86.6%). A series of concrete mixes was produced using a Response Surface Methodology (RSM) design, with varying percentages of nano-sized PET (0% to 5%). The properties of the resulting concrete, including slump, water absorption, compressive strength, flexural strength, and tensile splitting strength, were tested at 7, 14, and 28 days. Results showed that the inclusion of nano-sized PET materials generally reduced the workability (slump) of the concrete mixes. However, an optimal mix containing approximately 3% PT-nano demonstrated a significant enhancement in mechanical properties compared to the control mix, 5% at 28 days. Compressive strength increased by 6.04%, flexural strength by 34%, and tensile splitting strength by 2.7%. This optimal mix also exhibited a 9% reduction in water absorption. Conversely, replacement levels above 3% materials and the use of larger particle sizes (1.18 mm and 2.36 mm) in the mix led to a significant decline in all measured properties. The study concluded that a low percentage addition of nano-sized PET is a viable method to enhance the strength and durability of concrete, but particle size and replacement percentage are critical controlling factors.