Design for Disassembly steel frame structure
Ramboll / Kierrätyskeskus / GXN
Traditionally warehouses are designed and built for 50-year service life and they must be demolished when the building is not needed anymore. Warehouses are typically buildings, which are needed in a relatively short period and in a certain location. Therefore, structures of warehouse are designed according to DfD principles in this demonstration. This will contribute to prolongation of the building’s components lifetime, with the goal to minimize consumption of virgin resources.
The baseline to which the developed DfD structure is compared, is a typical non-movable warehouse structure. The goal is enable circulation of all structural elements including foundations.
The expected impacts
The embodied carbon footprint of DfD structures might be slightly higher in the first erection of the building but much lower in second and third erection compared to the baseline. Calculations will be made to test this hypothesis.
New structures developed in this demonstration will potentially increase circularity, reusability, material efficiency and cost efficiency of the structures over the whole life-cycle.
A design guideline for DfD structures is being developed during the design process, a operational design guide-tool specifying general design considerations for typical engineering challenges.
Baseline structure for the demonstration building is done. Structural components are modelled with BIM. Several cases have been studied to find the best combination for the space use, frame and foundations .
When designing for disassembly regulating factors such as loads, fire class, purpose of building etc. can be more challenging to comply with. hence such factors should be taken into account in early stages of DfD design.
Usually a structure is stiffened with trusses one in each of the four walls and two horizontal trusses on roof level to each wind direction. Baseline structure allows only steel frame reuse.
Developed structure need less material because more rigid connections of steel structures. additionally the size can be adjusted by adding or removing frames.
A demountable concrete foundation placed on ground allows for reuse.
There are no on-site welding connections. All connections in steel structures and concrete foundation as well are made by bolts. This makes all connections and joints removable for the purpose of reuse.
Columns can be shortened by 2 meters. This mean, that the height of the hall can be 3 meters or 5 meters. Column-column joint is rigid.
Rigid column-beam connection and joint of tubular beam to column
Final developed structure