Efficient steel structure for EADS Research Centre for Prototype Aeroplanes Madrid

Detailed information

The hangars and their steel structure

Project drafting and construction of the new hangars destined to house the Research Centre for Airbus Military’s MRTT (Multi Role Tanker Transport) Aeroplanes were executed in less than 15 months.

The T23 hangars, 80 m wide, 90 m long, and 24 m high, were built next to an existing hangar (T22), the design of which was replicated due to the short delivery period. However, a recalculation of T22’s structure made substantial weight loss of the new hangars possible.

The pillars of the T22 structure are HE 900 profiles, but according to the results of the new calculation, a smaller size would be sufficient to meet the new building’s requirements. Taking into account the new calculations, the profiles used for the T23 hangars are HE 700.

In this way, a total of 600 tns of material savings were obtained between the two hangars. Whereas the T22 structure needed 1800 tns of steel, each one of the new hangars only uses 1500 tns. These significant savings naturally also had an influence on foundation laying.

The roof trusses are triangular lattices with welded profiles and tubes. The top chords are made of two HEA 450 profiles and the bottom ones by two IPE 500 profiles joined to each other forming a drawer. Each truss weighs some 100 tonnes. In order to facilitate their conveyance, trusses were divided into 5 parts, each one 16 m long. The unions were done with high-resistance screws and 30 mm S275 steel plates.

Each hangar has 3 single-beam 24-metre-wide overhead travelling cranes, each one with a 5 tn capacity. The beam carriers are IPE 450 profiles.

The cover is of a deck type with a steel sheet on the bottom face, two insulating layers, and a waterproof FPA polypropylene sheet on the outside.

The hangar’s facade is mainly steel sheet and rock wool sandwich panels. In the walls shared with the office building and logistics area, pre-manufactured concrete panels have been used, with intermediate polystyrene insulation. A top fringe 3 m high of cellular polycarbonate has been placed which works as a skylight.

The hangars’ doors are composed of 7 sliding panels, each and all independently controlled. They consist of a steel structure on which sandwich panels were placed identical to those of the rest of the facade, including the skylight which continues on the doors. The 7 panels may be opened at the same time, leaving an open entrance 80 m wide and 20 m high, and joining in a space envisaged for this between the two hangars.

Air-conditioning is based on heat pumps, and the air distribution system is composed of nozzles on the ceiling and perforated sheet drawers placed along the inside facade of the two hangars at a height of 3 m to free up space in the building. The system is reversible so in winter the hot air impulsion is produced through the drawers and returns through the nozzles, whereas in summer the impulsion of cold air occurs through the deck nozzles and returns through the drawers. In this manner stratification is avoided.

The use of geothermal power

Deep foundation-laying by means of piles (more than 400 piles, 15 m deep) offered the possibility of making use of low geothermal power available underground. A total of 18 km of tubes for water flow were installed in piles to this end, which favours air-conditioning both in summer and winter, thanks to the fact that temperature as of 3 m deep is practically constant throughout the year (16-19 ºC).

Office building with ArcelorMittal floor beams

On the north-eastern facade of the hangars, a 4-floor office building was built that also houses auxiliary workshops and rooms on the ground floor. More than 800 people work there on a total surface of 13 200 m2. ArcelorMittal Type A IFB profiles (Integrated Floor Beams) were used for the structure of this building.

It involves a profile type obtained from a half rolled profile (HEA 500, HEB 500) to which a very wide flange plate is added, so that it is possible to place forged pre-manufactured plates keeping sufficient length of support (from 8 to 10 cm). In this case pre-stressed concrete floor slabs were used.

T23 in numbers

Surface:
AREA A (Hangar 1): 7320.42
AREA B (Hangar 2): 7320.42
AREA C (logistics area): 2742.08
TOTAL: 17 382.92
AREA D (Offices): 13 205.43
TOTAL: 30 588.35

Steel for structures:
Buildings: 2934 tn (2858 tn supplied by ArcelorMittal)
Offices: 705 tn (689 tn supplied by ArcelorMittal)

TOTAL tubes and rolled profiles: 3639 tn
Corrugated steel for concrete reinforcement: 765 tn