The evolution of material stock research: From exploring to rising to hot studies

Material stocks in buildings, infrastructure, and durable products play multiple roles in environmental and socioeconomic systems throughout their life cycle. After half a century of exploration, the study of material stocks has led to the development of a knowledge system. However, an overall picture of the evolution of knowledge in this field is lacking. With the aid of CiteSpace, a science mapping tool, we review 395 publications and find that the study of material stock experienced three obvious stages: initial exploration (1973-2005); rising period (2006-2016); and a hot period (2017-2020). The evolution of material stock research shows a clear objective-oriented mode. As research objectives evolved from macroscopic observation to refined management of materials, the main research content changed from observational accounting to exploring the application, role, and service functions of material stocks, especially from the perspective of systematic metabolism under the complex background of social transformation. Accounting items shifted from an initial focus on metallic materials to a broader set of materials and product stocks, and from accounting of a single category to multi-category accounting. The scale of research correspondingly shifted from the national and global scale to the urban and community scale which can serve refined management. These changes also led to in-depth and detailed study of the role and function of stocks. In the future, scholars should continue to explore and apply microscale models, whiten the black box in large scale research; focus on recycling of urban minerals and electronic wastes. Mapping the transformation of raw materials into products by combining material properties and product functions is crucial to concretely implement a circular economy. Differentiation, specialization, combination of approaches, and sub-categorical and sub-regional coefficients will be the key to future refined, lean, and precise accounting.

Automated summary

The study of material stocks in buildings, infrastructure, and durable products has evolved through three stages: initial exploration, rising period, and a hot period. Research objectives shifted from macroscopic observation to refined management, with a focus on exploring application, role, and service functions of material stocks. The scale of research also shifted to urban and community levels for refined management and detailed study of the role and function of stocks. Future directions include exploring microscale models, focusing on recycling urban minerals and electronic wastes, and implementing a circular economy through a combination of material properties and product functions.