FRAMEWORK FOR ENVIRONMENTAL ASSESSMENT OF USING INDUSTRIAL BY-PRODUCTS AND USED BUILDING MATERIALS

摘要

In Sweden, environmental assessments in the process of development permits regarding use of by-products and used building materials in constructions is mainly performed from the narrow perspective of the material itself, i.e. the material level. Certainly, such an assessment does not involve substitution of natural resources or environmental aspects of reuse in a wider sense. We argue that these mainstream environmental assessments should use broader system boundaries. We propose a framework based on four different assessment levels; (ⅰ) the material level, (ⅱ) the local environment level where the material should be applied, (ⅲ) the narrow life cycle level including a restricted life-cycle perspective and (ⅳ) the industrial system level where the production processes of the by-product or used building material and its actors are working. Consequently, these levels address different issues. An environmental assessment of reuse in general according to this framework would illuminate various aspects of each level. Moreover, each level involves different evaluation methods to answer addressed questions. For example, leaching tests are suitable at the material level in order to study which and how much substances that could leach from the material. At the local environment level, substance flow analysis can illustrate relevant flows and stocks in the nearby environment. At the narrow life cycle level an abridged life cycle assessment adds non-geographic but life cycle oriented information. Lastly, at the industrial system level, methods as strategic environmental assessment or extensive life cycle assessment could be used. The result of an environmental assessment use of by-products and used building materials using this broad framework would provide a good basis for a discussion about environmental performance involving consequences such as substitution of natural resources, local environmental impact, large scale effects, and global environmental issues such as supply of rare metals and climate change.