Construction and demolition waste (CDW) accounts for 30% to 40% of the total amount of waste in China. CDW is usually randomly dumped or disposed in landfills and the average recycling rate of CDW in China is only about 5%. Considering there is big challenge in adoption of circular economy in CDW industry in China while related research is still limited, we conduct the CDW management analysis through 3R principle. Existing policies and management situations were investigated and analyzed based on the reduction, reuse and recycle principles. Results reveal that primary barriers of reducing CDW in China include lack of building design standard for reducing CDW, low cost for CDW disposal and inappropriate urban planning. Barriers to reuse CDW include lack of guidance for effective CDW collection and sorting, lack of knowledge and standard for reused CDW, and an underdeveloped market for reused CDW. As for recycling of CDW, key challenges are identified as ineffective management system, immature recycling technology, underdeveloped market for recycled CDW products and immature recycling market operation. Proposals to improve the current situation based on 3R principle are also proposed, including designing effective circular economy model, reinforcing the source control of CDW, adopting innovative technologies and market

Urbanization and population growth have contributed to a tripling of building material consumption from 2000 to 2017. Building materials have a range of environmental impacts throughout their life cycle, from extraction, processing, and transport of raw materials to building construction, use, and eventual demolition and waste. Mitigation measures that target specific materials or value chain stages may therefore have incremental or even adverse net environmental effects. In this perspective, we develop a framework for applying life cycle thinking to identify key impacts and corresponding mitigation approaches, inform building design and material selection, and ensure effective treatment and recycling of construction and demolition wastes. Life cycle evaluation can also be used to assess and avoid environmental trade-offs among life cycle stages. Challenges for implementing these life cycle principles include collecting and integrating inventory data for products, managing multiple stakeholders within the construction industry, and monitoring end-of-life impacts; measures for overcoming such challenges are discussed.

This work is an attributional and consequential life cycle inventory assessment on the use of copper slag as a replacement for ordinary Portland cement. Assessments were done with respect to the emissions of seven kinds of heavy metals and four types of gaseous emissions. It was found that replacing cement with copper slag will reduce the emissions of cobalt, carbon dioxide, carbon monoxide and nitrogen oxides. However, it will increase the emissions of cadmium to the environment. This substitution may also reduce the emissions of arsenic, chromium, copper, lead, mercury and sulphur dioxide. In addition, three scenarios of likely consequences of this substitution were considered. It was found that these consequences will reduce the life cycle benefits of such a material substitution. Finally, four policy-making lessons were delineated.

Acoustic comfort is an important consideration in the design and construction of office buildings. Since the acoustic performance of a building will affect its inhabitants psychologically, sociologically and physiologically, post-occupancy evaluations of acoustic performance are often necessary to ensure that acoustic design features are effective. Since acoustic quality is often affected by the interplay among the building's interior, structural, envelope and mechanical systems, it is critical to assess acoustic quality in an integrated manner. This article presents a detailed acoustic evaluation of a three-storeyed office building by adopting a total building performance (TBP) approach. Through plan/archive analysis, expert walkthrough, objective acoustic measurements and analysis, the existing acoustic problems are identified. Subjective views of occupants regarding acoustic quality in the office and warehouse spaces are also sought. It was found that both objective and subjective data support each other. By understanding how these problems are caused by the interactions among the different building systems, specific solutions were proposed. In summary, this work highlights the usefulness of using a TBP concept to diagnose the acoustic quality of a multi-storeyed office building in an integrated manner. This project is motivated by an effort to promote workplace comfort and sustainability within the framework of corporate social responsibility.

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