Steel Applications Research Centre, Zelzate-Gent

The sleek toroid form of the Superdome, which resembles a racing helmet, helped to keep costs low as well as to provide an aesthetic stimulus. The structure of the main roof consists of steel open web trusses two meters deep at the crown and tapering towards the base. All the trusses are geometrically identical, but laid at ever increasing inclines the further they are located away from the building's lateral axis. A significant proportion of the roof's thrust load, however, is carried by steel ties running normal to the trusses down to a ring tie at the building perimeter. The Superdome creates efficient space containing 120m end-to-end and 95m across; the highest point of the roof rises to 30m above the arena floor. Offsite fabrication, repetitive elements and speedy on-site erection made steel the preferred choice of construction. Roof cladding of this light, bright all steel structure consists of off white spandrels laid at 45 degrees to the direction of the purlins with 50mm thermal and acoustic insulation placed directly under the roof deck and 50mm perforated insulation, incorporating a white polythene facing, on the underside.