Friday, April 9, 2010

Construction elements for Melbourne sports stadium

Construction elements for Melbourne sports stadium

ThyssenKrupp Steel Europe has supplied 25,000 square meters of steel sandwich elements for the construction of a new sport stadium in Melbourne. The stadium, which cost 267.5 million Australian dollars in total (around 180 million euros), is covered by a roof of Hoesch isowand vario® elements. Although originally developed for wall and facade applications, the isowand elements are perfectly suited to the special architecture of the stadium shell.

The new sports facility, recently named AAMI-Park after an Australian insurance company, is also known as "Melbourne Rectangular Stadium". Rectangular is a reference to the shape of the pitch, which is noteworthy in a country where the national sport of Australian Rules Football is played on oval fields. It means: Rugby and "European Rules Football" - i.e. soccer -will be played here in the future.

Rectangular is, however, not a word that could be used to describe the exterior of the stadium: Cox Architects + Planners, one of the largest architectural firms in Australia, has created a structure based on the geodesic dome designed by the American architect Richard Buckminster Fuller. This type of dome is made up of many small triangles held together by a fine lattice-like structure. It mimics construction principles that can be found in nature, is extremely stable and can enclose large spaces using comparatively small amounts of material. Cox Architects refer to their roof design as a "bioframe", which emphasizes its organic form. The outer shell of the stadium resembles a large ring of intertwined, finely structured hemispheres open to the pitch.

The bioframe concept is not only aesthetically pleasing, but also cost-effective. Protecting the 30,000 plus spectator seats from the wind and weather required around only half the material that would be needed for a conventional design using a so-called cantilever roof. However, the concept places special demands on the materials used. Low weight is important as there are unsupported spans up to six meters wide to be bridged. But as well as lightness, good insulation properties are also important to ensure that conditions remain comfortable under the stadium roof even in the Australian sunshine. Good fire safety properties are also indispensable in such large-scale structures used for mass events. The design requires precision-fit parts and also has to meet the architects' high design requirements.

Light, first-class insulation values, good fire safety properties, precision joint geometries and high-grade appearance: To find the ideal product for these requirements, Grocon Pty. Ltd., the Australian construction contractor responsible for erecting the stadium, turned to the Australian construction systems sales unit of ThyssenKrupp Steel Europe. Hoesch isowand vario® is a steel sandwich element designed specially for modern industrial architecture with high aesthetic requirements. The element, which comprises two thin steel face sheets enclosing a thick polyurethane rigid foam core, has first-class heat insulation properties and is low in weight. Hoesch isowand vario® has concealed fastenings as well as precision joints. The elements are available in smooth, lined, microprofiled and v-profiled finishes. Perfect corrosion protection is ensured by means of a duplex coating system, in which first a zinc layer and then a paint or plastic finish is applied to the steel face sheets. The elements can be supplied in thicknesses of 60, 80, 100, 120 and 140 millimeters. Hoesch isowand vario® is classified as a flame retardant construction material in accordance with EN 13501-1.

The bioframe roof of the Melbourne stadium is made of 100-millimeter-thick isowand vario elements weighing just under 13 kilograms per square meter. The elements were cut into equilateral triangles and fitted with aluminum frames by Melbourne based Minesco Pty. Ltd. and then delivered ready for assembly to the construction site. Rubber seals, also fitted by Minesco engineers before installation, ensure that the roof structure is waterproof. ThyssenKrupp Steel Europe realized the "whisper white" shade selected by the architects using a high-quality PVDF coating (polyvinylidene fluoride). The plastic layer is 25 micrometers thick and - thanks to its high chemical and thermal resistance - will ensure that the surface remains impervious to the effects of environmental influences and sunlight for years to come. The surface of the elements is microprofiled to enable rainwater to run off easily into tanks for subsequent use as service water in the stadium. Rainwater management is part of the sustainability concept for the stadium which also includes an integrated waste and recycling system.

The new stadium will be inaugurated with on May 7, when the Australian rugby league team will meet the New Zealand national side.

No comments: