Mechanical and Physical Performance Evaluation of Laboratory-Scale LDPE-Sand Composite Modified with Rice Husk, Rice Husk Ash, and Biochar

Abstract

For a developing country like Nepal, the massive increase in amount of plastic waste and agricultural leftovers has created serious environmental issues. This study focuses on the development of plastic-sand composite bricks, using low-density polyethylene (LDPE) plastic as a binding material and sand as the aggregate. The control mix of plastic and sand only as well as the modified composites using rice husk, rice husk ash, and rice husk biochar were prepared as partial replacement of sand to study the change in material properties. Laboratory scale samples having dimensions of 100 × 50 × 50 mm were fabricated using a mix ratio of 30:70 (plastic to sand) by weight, with 10% replacement of sand by agricultural derivatives for additive based samples. The fabricated composite material was tested for their compressive strength, water absorption, and physical properties, and FTIR analysis. The highest average compressive strength of 19.34 MPa was shown by rice husk ash sample. Raw rice husk sample had the lowest average value of 15.56 MPa. The rice husk biochar sample showed moderate performance with strength of 17.07 MPa. FTIR analysis confirmed that bonding in the composite is mainly physical. This study shows that LDPE-Sand composites with suitable agricultural additives can work as sustainable construction materials and helps to promote effective waste utilization.