Steel is one of the most widely used and resource intensive materials used in construction. Although commonly recycled at end of life, the reuse of steel is minimal despite the apparent environmental, carbon and circular economy benefits. The high value of steel at end of life can be realised by being reused in a wide range of construction applications.
The below diagrams demonstrate steel recycling (BAU) and three main steel reuse supply chain models. This comes as part of research by Dr Asselia Katenbayeva, Research Associate, ASBP, as part of research into ASBP's DISRUPT project, linking to our Reuse Now Campaign.
Scrap steel from demolished buildings is sent to metal recyclers for re-melting or exporting.
Reuse model: Stockholders driven
Stockholders purchase reclaimed steel from demolition contractors and then sell it in the open market. Stockholders perform the initial processing of reclaimed steel, such as sandblasting to remove paintings and coatings. Reclaimed steel is tested and certified, the complexity of which might depend on the amount of information available on the reclaimed elements (e.g. material properties, steel grade, previous testing). Certified steel is then supplied for fabrication and assembly on site as usual.
Reuse model: Clients driven
In this model, clients recover steel from their demolished (donor) buildings for reuse within their new (recipient) buildings. The ownership over the reclaimed steel is retained by the clients throughout the entire process of steel reuse. In this model, information on reclaimed steel (e.g. material properties, steel grade, previous testing) is typically available and therefore, testing and certification tend to be more straightforward. However, the design of the new building is limited to available steel sizes and sections from the demolished building.
Reuse model: a Hybrid model
The hybrid model is a combination of the previous two models. As reclaimed steel from a donor building is often insufficient for a new building, additional reclaimed steel (from other projects) is purchased from stockholders.