Eco-efficient demolition techniques and sustainable construction and demolition waste (CDW) recycling methods

Demolition techniques and the management of construction and demolition waste of buildings are key issues in the development of sustainable construction. Prevention, reuse and recycling are the basic approaches to waste management. Demolition techniques which have hitherto been unsafe, dangerous and uncontrolled are today developing into an engineering discipline. Thus demolition of buildings is now a well planned part of civil engineering with many aspects to ensure a safe demolition phase. Buildings now reaching their end-of-life were not constructed in the past with thoughts of later reuse of materials or structures. Even today, demolition as one possible strategy at the end-of-life of a building is not deeply investigated. While buildings from the latter half of the last century reach their end-of-life, and rebuilding at the same places becomes ever more important, demolition techniques also become increasingly important. The boundary conditions are a dense building development and high traffic rates, so that any uncontrolled methods for demolition are no longer appropriate. Sustainable construction does not finish at the end-of-life of a building. Since demolition waste is one of the biggest components of all waste, its impact on resources is non negligible. Thus landfilling should be avoided and use of the recycled material needs to be enhanced. This paper takes a closer view to the waste streams and considers technical possibilities during the demolition to avoid unnecessary waste. Methods such as the top-down method and the four-phases-model are introduced. Demolition is still however producing a lot of waste and as such, there is a need for alternatives and recycling to make demolition more eco-efficient.