Structure Transition and Circularity Gap of Sand and Gravel Resources in China
- 1Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
- 2Institute for Circular Economy, Tsinghua University, Beijing, 100084, China
- 3Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7495 Trondheim, Norway
- 4School of Business, East China University of Science and Technology, Shanghai, 200237, China
- 5School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China
- 6School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, 48109-1041, USA
- 7Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, 48109-2125, USA
- 8Center for Environmental Systems Research (CESR), University of Kassel, 34109 Kassel, Germany
- 9Energy, Climate, and Environment Program, International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, 2361 Laxenburg, Austria
Aggregates (collectively sand, gravel, and crushed stone) are the most extracted material by weight over the world, and they are important raw materials for buildings and infrastructure. Owing to its rapid development, China is the largest aggregate consumer and producer, accounting for over half of the global aggregate consumption. However, aggregates in China are now facing shortages and low resource circulation. As a long-neglected resource, it is difficult to provide sufficient support for relevant policy-making without a comprehensive quantitative basis. To bridge the knowledge gap, first, we established a systematic material flow and stock accounting framework to map the social metabolism of aggregate resources in China. Then we discussed the results in the global context for international comparison to figure out the circularity gaps of aggregates in China. Our results show during 1978–2018, the inflows of China’s aggregates increased by 13 times (1.3 to 17.3 billion tons), the stocks increased by 15 times (18.3 to 285.5 billion tons), and the outflows, the main component of CDW, increased 9 times (from 445 million tons to 4.4 billion tons). On the supply side, a transition of the primary supply structure is observed. The manufactured aggregates gradually replaced the natural aggregates as the main supply source in the past decade. On the demand side, the demand for aggregates stepped to a peak of around 18.5 billion tons. The infrastructure rather than building becomes the main consumer since 2014. However, the model shows the recycling rate of outflows is less than 5%, indicating a circularity gap compared to the rate that could be as high as 70%–95% in certain advanced economies. The market acceptance, policy supports, and the structures of demolished buildings are the main reasons for the current circularity gap of aggregates. Regarding a large amount of aggregates accumulated in the material stocks, it is expected to see rapid growth of aggregate waste in the near future. It is essential to foster a well-functioned circular system to achieve the sustainable development of the aggregate industry.
How to cite: Ren, Z., Jiang, M., Chen, D., Yu, Y., Li, F., Xu, M., Bringezu, S., and Zhu, B.: Structure Transition and Circularity Gap of Sand and Gravel Resources in China, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11232, https://doi.org/10.5194/egusphere-egu22-11232, 2022.
