Turning Plastic Waste into Construction Materials
Dr Simon Wong, Faculty of Science and Technology
Hong Kong is currently facing problems caused by the dumping of over 2,000 tonnes of plastic waste each day. As plastic waste degrades slowly, it occupies a large volume of landfill space. Toxic substances leaching from plastic waste to the environment can contaminate the ground water and harm the ecosystem. In addition, incomplete incineration of plastic waste may create toxic emissions like sulfur dioxide, sulfide, and dioxin. Therefore, it is imperative to study alternative uses of plastic waste so as to reduce the environmental damage caused by the disposal.
To mitigate the crisis of plastic waste, Dr Simon Wong investigated how recycled plastic materials could be incorporated into asphalt, a road pavement material, for making the surfaces of roads. By using plastic waste as a modifier, the performance of original asphalt can be improved. The advantages of mixing the modifier with asphalt include better physical properties of pavements, a lengthened service life and increased durability of roads. Importantly, this enhanced source of construction materials can be produced at a low cost. Since a considerable amount of construction materials are needed for new road development and rehabilitation of existing road networks in Hong Kong, the consumption of plastic waste can reduce the occupation of landfills.
Penetration test of plastic modified bitumen
In response to the call from the Environmental Protection Department to develop a sustainable waste management strategy, Dr Wong’s project has turned plastic waste into useful and economical materials for paving roads.