Valorisation of LDPE Waste Reinforced with PET as a Binder in Development of Construction Materials

The proliferation of plastic waste represents one of the major environmental challenges facing modern society. This study aims to valorise lightweight plastic waste, which is currently subject to low recycling rates, in order to reduce its environmental impact. To this end, a mixture of low-density polyethylene (LDPE) waste and polyethylene terephthalate (PET) waste was melted at a temperature of 250°C. Following complete melting, sand was incorporated into the molten polymer, and the mixture was progressively mixed until a homogeneous paste was obtained. Composite materials were produced with plastic contents of 10%, 20%, 30%, 40% and 50%, the remainder consisting of sand. The resulting paste was then cast into moulds and compacted using an electric impact compactor applying 60 blows per mould. The manufactured materials were subsequently subjected to physical and mechanical testing. The best performance was achieved by the formulations containing 40% and 50% plastic. The corresponding compressive strengths reached 10.13 MPa and 21.85 MPa, respectively, while the flexural strengths were 4.33 MPa and 10.55 MPa, respectively. The mechanical properties of the developed composites comply with the requirements of the relevant standards. These findings demonstrate that the developed materials have significant potential for use in road pavement applications.