Civil Engineering Reference
In-Depth Information
Figure 1.3: The main layers of a building.
Source: Brand 1994
component, which then enters a new manufacturing process. This is a very effi-
cient method for metals. For other materials different methods of down-cycling
makes less valuable products, e.g. reducing high quality PVC articles to flower
pots, or crushing light-weight concrete blocks into aggregate.
Where products claim to have a potential recycling, the statement is often
based on theoretical figures. In practice there are often complications: thin alu-
minium fibre or containers burn up totally or evaporate when being melted
down, while small amounts of impurities in the worst cases can lead to extra
refining processes and a higher use of energy.
Energy recovery
means burning the product to produce energy. It is an advan-
tage if the material can be burned at a local plant and if the fire gases do not need
special treatment, so that simple furnaces can be used.
Assembly for disassembly
Designing for the direct re-use of building materials gives the best opportunity for slowing
down the trip to the rubbish dump. The Assembly for DISAssembly (ADISA) principles
gives some fundamental guidelines for optimizing the re-use of single components.
