New opportunities for the development of construction and demolition waste in the construction industry in Hong Kong under the circular economy framework

Hong Kong's overall construction waste accounts for approximately 23% of its total solid waste. As the aging rate of buildings accelerates in Hong Kong, the number of buildings reaching 50 years old is projected to increase from 8,700 in 2020 to 13,900 by 2030. Recently, deteriorating older buildings have become potential sources of construction and demolition waste, leading to a significant rise in the total amount of construction waste. Traditionally, Hong Kong has managed construction waste by using it as landfill material or burying it, but such practices are unsustainable in a city where land resources are scarce.

To alleviate the growing volume of construction and demolition waste, a circular economy approach emerges as a solution. However, there is a lack of research on implementing a circular economy model that treats construction and demolition waste as secondary building materials in the construction industry. This study focuses on the Tseung Kwan O landfill site as a case study, analyzing predominantly concrete waste generated from existing construction waste. The research explores how abandoned concrete can be effectively recycled and repurposed as a material. Additionally, it examines the integration of circular economy principles into the industry.

The study concludes that incorporating recycled concrete aggregate (RCA) as a component in the construction industry's circular economy is feasible and environmentally beneficial. The establishment of a comprehensive management system for construction and demolition waste is a crucial first step towards realizing a circular economy in Hong Kong. This research provides a framework for formulating waste management policies in the construction sector, enhancing collaborative processes among stakeholders, and aiding relevant authorities in regulating construction activities.