9,000 m2 of steel sheet-concrete floors for the garage of the future 

Multifunctional, innovative and sustainable. On the corner of Industrielaan and Paepsemlaan in Anderlecht, an ambitious project is under construction: the Mobilis garage of the future. On a 10,400 m² site, a unique 35,000 m² building with a flexible structure is being created, bringing together a green and urban ambition, far-reaching logistics services and bold architecture. While the lower levels will house sales areas and showrooms for Volkswagen, Skoda and Seat/Cupra, the other floors as well as the roof will focus on a variety of urban activities. The permits for Mobilis were issued at the end of January 2021 and Alheembouw started construction work about three months later. For the design, engineering and realization of the steel-plate-concrete floors, the main contractor sought the cooperation of Tullingh & Partners.

Slim, fast and highly efficient

Significant weight savings, minimal concrete use, better construction connections and perfectly coordinated logistics and assembly. But also: shorter lead times and lower overall project costs. It is not for nothing that Tullingh & Partners' steel deck concrete floors are frequently used in new construction, renovation, transformation and expansion projects. Whereas hybrid steel-plate concrete floors are particularly suitable for (utility) roofs, uninsulated steel-plate concrete floors are often used for intermediate floors in interior situations and for parking garages. Such is the case in the garage of the future in Anderlecht, which has a total of four floors. "The second and fourth floors of Mobilis are constructed as in-situ concrete floors; a so-called wafer floor," explains Charles van Oldenbarneveld of Tullingh & Partners. "For the first and third floors, steel plate concrete floors with a special fastening were chosen. The steel structures for these intermediate floors are suspended under the concrete floors by means of a garden construction. On top of this we install the steel plate-concrete floors, for which we made a custom (execution) design."

Fully customized

The steel plate-concrete floors in Mobilis have an area of approximately 4,500 m2 per floor and are characterized by low profiling. "A low own weight of a maximum of 200 kg/m2 was prescribed for the floors," says Van Oldenbarneveld. "And specific requirements were also set for the maximum load capacity (500 kg/m2) and fire resistance (120 minutes). Based on these data and in a fine cooperation with Alheembouw, we engineered the structural floor in detail." By designing floors 15 cm high, facilities such as climate systems could be fitted in perfectly, he says. "Upon completion, Mobilis must meet BREEAM 'Outstanding' criteria and 100% energy-neutral operation. Following photovoltaic solar panels, a green roof and reuse of rainwater, the climate systems make an important contribution to this."

33,500 welding dowels

The average span in this project is 4 meters, said Van Oldenbarneveld. "A large part of the storey floors will be assembled without underpinning. For this reason, for example, lightweight concrete is used. For cooperation with the underlying steel structure, as many as 16,750 welded studs per floor (total: 33,500 pieces) are attached."

Special design

The garage of the future has an unusual and dynamic shape, aligned with the street. "The shape of the building is pleasing to the eye, but also brought challenges," says Van Oldenbarneveld. "For example, all the typesetting and fittings were contour cut in advance and based on the structural information from the BIM model. The rest of the floor structure is made to fit on the job." In doing so, Tullingh & Partner works according to a tight assembly schedule. "For the execution, the building is divided into quadrants. For each quadrant and each floor, we spend about a week assembling and finishing the profile plates. Then all the dowels are welded in two weeks." Because the concrete floors on the second and fourth floors have already been poured, free overhead space is lacking. Therefore, all the steel plate packages are placed on the steel structure from below and with the help of telescopic handlers.

Finally, a special feature is that all the steel plates for Mobilis are coated on the underside with a white PVDF coating. "The steel plate concrete floors remain visible as a ceiling after completion," said Van Oldenbarneveld. "Because part of the floors protrude to the outside, the coating thickness is carefully matched to the outdoor climate. As a result, protection and beautification come together perfectly."