Galvanized steel is the perfect circular material to ensure that buildings and structures can be designed with maximum flexibility and to enable construction products to be used across multiple lifecycles. Future designs of steel structures will become more modular and utilise bolted connections to ease deconstruction and make components more widely suitable for reuse. Galvanizing creates more value to these reused components as they do not require further protective treatment and the components themselves will be in good condition at the point of reuse.
Galvanized steel will not suffer from demounting and remounting activities, as opposed to painted steel which will need to be repainted or at least repaired. Moreover, galvanizing offers longer lifetime expectations to steel than other coating systems, which allows frequent reuse of the material.
In addition to its durability, the toughness and abrasion resistance of galvanized steel, allows for multiple reuses of steel components. This has proven itself in a wide variety of applications – from scaffolding that is reused countless times to temporary bridges that are designed for rapid deployment in disaster zones but often become a vital part of the local infrastructure and may enjoy many decades before moving on to their next location.
These same principles and experience with temporary structures and reusable components are now being applied to the design of more complex structures that require flexible solutions for the circular economy.
PROGRESS (PROvisions for Greater REuse of Steel Structures) was an EU RFCS-funded project focused on the reuse of single-storey buildings. The study and its recommendations provide additional impetus to the future use of galvanized steel to maximise reuse opportunities.
The project has delivered recommendations and practical information on the fabrication and detailing of single-storey buildings made from reclaimed steel, and on the design of buildings for future demounting and reuse. Future optimisation of connections and other design details will further reinforce the partnership between galvanizing and steel construction. For example, the use of bolted connections has the dual benefit of enhancing prospects of reuse whilst also increasing the size of sections that can be dipped in a hot dip galvanizing bath.
Rebirth of a grandstand after 40 years
In summer 2011, Harry Haverkotte, former board member of SV Gramsbergen, heard that their neighbours from Hoogeveen would move to a new sports park. The good condition of the main grandstand caught his eye so he bought it for €7,000 including the cost of disassembly. The stand was originally built in 1976. Back then, the board of Hoogeveen awarded the construction for 139,200 Dutch florins (€163,000).
Within two years, a wonderful 32 metre long stand arose from the ground. Eventually, the stand only cost €35,000 while a new building would have at least cost €200,000. Everything was reused, apart from the bolts, nuts and the old wooden boards. The boards were replaced by new seats. The only decorative paintwork that had to be done was on the inside of the roof. The excellent state of the galvanized steel was confirmed during disassembly. The outer structure had spent 40 years exposed to the weather, but the galvanized steel was in perfect condition and did not need to be regalvanized. The remaining galvanized coating is more than 100µm thick and the stand will last for many more decades and potentially many more reuses.
1 | Schematic of toughness and abrasion resistance of galvanized steel.
2 | Portal frame designed for reuse with modular and standardised elements (PROGRESS project).
3 | Material reuse flowchart (PROGRESS project).
4 | The reconstructed stand at SV Gramsbergen ready for another lifecycle for its galvanized steel that could reach 100 years in total.
Image: Maité Thijssen, Zink Info Benelux