Design for Disassembly of Super-Light Concrete Structures

Concrete structures are sometimes believed to be less sustainable and difficult to disassemble properly compared to structures of other materials. However, when a holistic design approach and novel technology is applied in the design of concrete structures, they can be more sustainable than other solutions and designed for disassembly. A novel concrete technique, developed at the Technical University of Denmark, the Super-Light Deck, is one example of this new green generation of concrete. Pre-stressed deck elements of Super-Light concrete consist of a combination of light aggregate concrete and normal concrete. The flat decks can be used individually in buildings as horizontal divisions, or several decks can be joined together by post-tensioning in an arch shape for use in bridges or in vaulted roofs (the pearl-chain method). The technology makes it possible to create beamless structures by having blade joints between deck and support in buildings. Furthermore, an arch shaped structure consisting of several Super-Light Decks can be joined to the supporting structure by a designed “end-element” with a behaviour comparable to a concrete hinge. Both of these solutions are presented in the paper. They are novel designs, where the disassembly process is taken into account, and it will be possible to dismantle and reuse the Super-Light Deck elements, at the end of the lifetime of the structure.