The mechanical behaviour of waste plastic milk bottle fibres with surface modification using silica fume to supplement 10% cement in concrete materials
Robert Haigh
Abstract
The building construction industry’s heavy reliance on concrete and cement-based composites has given rise to pressing environmental challenges, including resource depletion, greenhouse gas emissions, and waste accumulation. To combat these issues, researchers have sought innovative approaches to integrate waste materials into concrete, offering promising sustainability solutions. This study focuses on the mechanical behaviour of concrete using waste plastic milk bottle fibres to replace 10% of the cement requirement. Both raw milk bottle fibres and surface modified fibres using silica fume (SF) were mechanically analysed for their compressive, flexural, and tensile strength. The microstructure of the composite materials was investigated via scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDS) to determine the effect SF has as a modification technique. SEM and EDS results revealed sufficient bonding of SF to the waste plastic fibres. This surface modification technique enhanced the mechanical strength by creating a denser composite matrix and increased bonding capacity of the fibres. Non-modified fibres resulted in a lower mechanical strength however, SF modified fibres increased the compressive, tensile, and flexural strength by 16%, 16.6%, and 11%, respectively. This study highlights the positive mechanical impacts when redirecting milk bottle containers from landfill toward the utilisation in concrete. Ultimately, the use of waste plastic milk bottle containers in concrete can contribute to sustainable trends in construction materials.