Demolition waste generation and recycling potentials in a rapidly developing flagship megacity of South China: Prospective scenarios and implications

China's construction industry is huge and widespread. Massive construction, particularly the large-scale urban renewable activities in megacities, inevitably causes billions of tons of construction and demolition waste, and arouses great environmental concerns, which have not been well documented. The need for accurate data and informed analyses and further policy making are therefore paramount. Case studies of a rapidly developing flagship megacity, Shenzhen city in South China, in-depth surveys on construction and demolition sites, recyclers and government department shave been conducted to obtain fundamental information about demolition waste from its generation to disposal. Next, advanced methods to estimate and extrapolate the generation, flows and utilization options of demolition waste have been created. Results show that approximately 14 million tons of demolition waste has been produced in Shenzhen city annually from 2010 to 2015 and will trend upward in near future. The recycling potential based on current utilization options is valued at around 1.02 billion USD in 2015 and this number could soar to 1.38 billion USD if recycling rates are maximized. To summarize, the findings of this study provide quantitative documentation for generators, recyclers and the government to take responsibility for sound management of demolition waste, including waste collection, transportation, utilization options and landfill planning. This approach could give insight into the quantification of demolition waste if applied to other megacities and across China