Material flow analysis of construction and demolition waste recycling under circular economy

The goal of the circular economy in construction and demolition waste (C&DW) recycling management is to reduce or even eliminate the dumping of C&DW into landfills or incineration. It also aims to scale up the recovery, reuse and recycling of C&DW and to realize the potential of recycled products from C&DW to be used in new buildings. This paper takes Guangzhou City, China, as an example, and applies the material flow analysis method to establish a detailed material flow analysis framework and indicator evaluation system for the C&DW recycling system. Subsequently, through the data collection of the production of C&DW in Guangzhou City in 2022, this paper constructed a visualized Sankey diagram of the C&DW flow, sorted out the flow and direction of the C&DW flow and conducted an in-depth analysis of the evaluation indexes of the system. The study obtained a recovery rate of 39.1 % for the C&DW recycling system and only 9.2 % for the C&DW recycling rate. It shows that the current Guangzhou C&DW recycling system is less efficient in the recycling and utilization of materials, and there exists a greater potential for value-added to the circular economy, and finally indicates the need to further study and analyze the obstacle factors in the development process of C&DW recycling under the circular economy. The research results can provide theoretical guidance for the formulation of policies related to the recycling of C&DW under the circular economy.