Nowadays, only a small fraction of steel elements coming from demolition works find their way to the reclamation market. This unfortunate finding has different reasons. On one hand, because these materials can be resold easily and cheaply to scrap dealers who sell them on through the recycling networks. On other hand, because their reuse for structural purposes can give rise to questions about the stability of the structures and the safety of the people, which require a proper assessment and taking responsibility by the participants in a building project (contractor, designer).
Steel beams and other steel sections found on the reclamation market come from a variety of sources, such as dismantled hangars or industrial destocking.
Environmentally speaking, reclaimed steel elements have excellent performances. The production of a steel component (even when it incorporates recycled steel) causes a substantial environmental impact, in particular associated with burning in blast furnaces, which produce large quantities of greenhouse gas. From this point of view, reuse constitutes a particularly effective strategy for extending the life of a steel component: every tonne of steel reused makes it possible to avoid the production of 1.3 tonnes of CO2.
Among common products, one can find:
- different sections of variable dimensions
- dismantled industrial hangars (see also category Hangars)
- metal framework
Components are usually sold at 50% of the equivalent new price.
Some dealers will buy structural metals at a higher price than scrap dealers if they meet certain very specific criteria. Take-back prices work out at around 200% of the scrap price.
Only a few dealers will give specific information about the performances of reclaimed steel elements. However, many of them can provide an opinion based on their observations and experience. When they have dismantled the structure themselves, they can possibly attest to the quality of the dismantling process and the completeness of the lot. Some dealers, however, do test the elements and can therefore express precisely some properties that are important to model the mechanical behaviour of the structure.
For designers and builders who want to work with these products, there are a series of measures available so that they can use these elements in full knowledge of all the facts. The application of these measures depends on the scale of the projects and the intended new uses:
- reserving the reusable structural components for secondary uses (secondary structures, non-structural uses, etc.).
- allowing adequate safety margins in the sizing calculations and adopting redundancy principles (using similar strategies to those used in renovation projects).
- gathering information on the origin and uses of the sections.
- making a careful visual inspection, possibly supplemented by specific tests aimed at establishing the actual performances of the materials (indentation tests to establish the hardness of the steel, infra-red scan, load tests on samples, etc.).
Did you know?
Many inspiring projects have demonstrated that reusing steel elements at the scale of a whole building is not only possible but very interesting on environmental and economic levels. These projects usually hinge on a combination of factors, such as a good collaboration with specialised dealers, an involvement of engineers able to assess the performances of the components and innovative approaches to demonstrate the fitness-for-reuse.