Preliminary Investigation of the Suitability of Coir Fibre and Thermoplastic Waste as a Construction Material

Waste polyethylene creates serious environmental and social problems in Sri Lanka. The amount of waste polyethylene increases daily, further aggravating environmental and social issues. Finding out the most suitable solution for this is a vital requirement. This research focuses on investigating the possibilities to convert this waste polyethylene as a sustainable construction material by combining it with readily available coconut fibre. A preliminary investigation was carried out on thermoplastic/coconut fiber composites to evaluate their suitability in the construction industry. Composite sheets, 2.5 mm and 3.2 mm thick, were developed by varying coir fibre weight with a suitable polymer matrix using a hot press machine. In this step, mechanical properties of the composite material were measured through tensile and bending tests. The tests were carried out complying with ASTM D3039 and ASTM D790, respectively. The surface morphology of coir fiber and the fractured surface of failure material were investigated through Scanning Electron Microscopy (SEM). Maximum tensile strength was observed as 6.75 N/mm2 when the coir wt. fraction is inbetween 20-30% by total weight. The maximum bending strength was 29.85 N/mm2 when the coir fraction is almost 25% by total weight. The corresponding mechanical properties are compared with the available materials in the industry.