A case study of construction and demolition waste management process flow in mega infrastructure projects in Australia

The rapid growth of population and associated urbanization and economic development calls for increased demand for infrastructure development to meet ongoing and future demands. A better understanding of the waste management (WM) processes would help to manage large volumes of waste effectively at construction sites, maximise the value of resources and improve environmental and economic performances. This research aims to investigate the WM processes associated with different types of construction and demolition (C&D) waste generated by a mega infrastructure project through a case study approach, combining expert interviews and project-specific document reviews. The case studied project demonstrated high environmental and economic sustainability outcomes and exceeded the C&D WM targets, signifying more than 90% landfill diversion rates for both spoil and construction waste generated during the construction stage. As such, the infrastructure projects have a great potential to maximise the reuse of high-value waste through waste exchange across projects and gain economic and environmental benefits, while leading to paving a path to greener Australia in near future. The outcome of this case study is a WM process flow diagram (PFD) that maps out the WM processes, waste fates and associated waste flows involved with the diverse range of C&D waste throughout its life cycle. The PFD developed in this study serves as an operational tool to develop effective WM plans for construction projects of similar nature and thus helps to achieve higher landfill diversion rates. The outcome of this study can also contribute to the development of a generic WM PFD for the C&D waste stream.