Johannesburg’s Soccer City, one of the most spectacularly beautiful buildings to rise from the 2010 World Cup stadium construction boom, was officially handed over to the city’s mayor at the beginning of March.
In one important construction detail it has epitomised the creative architectural value of the pre-stressed hollow-core concrete panel system. Echo Prestress says it has also demonstrated – in an international showcase setting – the important economic benefits inherent in its concrete panel system.
The calabash inspired design places the stadium on a raised podium, the ‘pit of fire’, so that the stadium seems to sit in a shallow depression – creating the effect of an African pot being naturally fired. A tight construction timetable required Echo Prestress to install 6 000m² of 150mm deep, 4.5m long, pre-stressed hollow-core concrete panels for the stadium kiosks and entrance areas within strict delivery and budgetary constraints, says Echo Group technical director Daniel Petrov.
The slabs are supported by raked steel beams and placed at an angle following the line of the beams to form the roofs over the kiosks and entrances. Between the steel supports the slabs are confined by end-stops, to restrict lateral movement. All were screeded and waterproofed to architectural detail.
“The Echo slabs met the architectural and structural engineering requirements,” Petrov adds. “Previously, stadium kiosks have traditionally been built using cast in-situ concrete. At Soccer City, however, our consistent product quality and efficient delivery arrangements helped the contractor to manage the demanding installation timetable.”
The benefits of using the Echo Prestress panels – typically the speed and ease of construction – were once again demonstrated in this project.
“No formwork or propping was required, so there was no inconvenience of restricted access, which would certainly otherwise have been the case,” says Petrov. “Once the slabs were installed, access to work spaces was totally clear and the installation of gates and turnstiles could go ahead without being restricted by props.”
The 90 000 capacity stadium last year won two prestigious Fulton Awards from the Concrete Society of Southern Africa – for Concrete in Architecture and as the winning Building Project for its demonstration of ‘excellence in concrete’.