Supply Chain Integration for Structural Steel Reuse

There is growing pressure on the construction industry to be more resource efficient, reduce waste and to lower embodied carbon impacts. Large structural steel components, particularly steel beams and columns used in construction, are not normally damaged during use. So at their end-of-life we may be able to reuse these components intact, rather than recycling them as scrap. Reusing steel components directly saves the energy and carbon emissions required to melt the scrap steel to liquid form before casting and forming the steel back into a useable product.  The widespread reuse of structural steel will require several changes to current construction and demolition practices: buildings will need to be deconstructed carefully instead of demolished; recovered steel sections will need to be reconditioned and certified; designers will need to learn to specify reused steel.  Small-scale reuse of structural steel sections takes place at the domestic-scale but the widespread reuse of structural steel has yet to take off. Studies have shown that several barriers prevent steel reuse at larger scales, although few barriers appear to be technical. Instead the matching of supply and demand—ensuring steel in the buildings being taken down is available for new projects where reused steel is desired—has been identified as a key barrier. Found and described 30 case studies – buildings and business models mainly from the UK, but also US and Canada. Case studies presented successful and unsuccessful steel reuse. Conducted 30 interviews with different actors from the supply chain: clients, architects, structural designers, general contractors, steelwork contractors, steel stockholders, demolition contractors. Prepared open on-line survey with 24 survey completed. The UK annual steel demand in 2015 for all steel products is around 10.4 Mt. Around two thirds of structural steel used in the UK is imported. UK consumption of structural steel (rolled and fabricated sections, hollow sections) in 2015 was 0.867 M of which 0.730 Mt was used in the buildings. The UK (2015) generates around 9.0 Mt of steel scrap from all steel products (excluding mill own scrap arising). In 2015 78% was exported for recycling. It is difficult to determine accurately the quantity of structural steel arising from demolition. It is estimated that around 7% of heavy structural sections / tubes is currently reused and 93% is recycled. The difference between the price of new steel beams (Long Products / Medium sections / Europe domestic delivered) and steel scrap (grade OA) has been £313/t on average, with a minimum range of £187/t since 2000. Steel reuse should be profitable if the total cost of reconditioning, testing, deconstructing and additional transportation of the reclaimed steel is no more than £187/t. The availability of reclaimed steel sections in principle, should not be a barrier to more widespread reuse. Based on interviews and an on-line survey there were identified 7 common barriers which were ranked by importance according to the number of mentions. Both interviews and survey yielded the same ranking: 1. Availability/ dimensions 2. Quality/ certification/traceability 3. Profit opportunity/ cost 4. Programme 5. Trust/Lack of communication 6. Uncommon practice 7. Old/New perception 8. Design for deconstruction As a further analysis, the global ranking was compared to the ranking for each actor type. We computed a metric which indicated that although the perception of barriers is rather uniform across the value chain, their effects are felt more acutely by fabrication and demolition contractors as well as steel stockholders. From the interviews across the value chain, all the costs associated with reusing structural steel were collected. A good estimations of the minimum and maximum for various operations necessary for fabrication and erection of both old and new elements was established. It was found that reused steel is only slightly more expensive than new steel. This gives hope that this difference could then be overcome with larger-scale operations. Successful, cost-effective examples of reuse can be explained by the elimination of one or more of the cost components (e.g. testing, transport, re-fabrication).