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The black facade of the Montblanc building is aesthetic, eye-catching and structurally demanding
The writing instrument manufacturer Montblanc has set up a permanent exhibition in Hamburg. The new building is characterized by its black, elaborately designed façade. The creation of this building cladding presented those responsible with major challenges, which were solved in an outstanding manner.
Montblanc, the manufacturer of high-quality writing instruments, has opened a permanent exhibition in Hamburg, with scenography and interior design by the Büro Projektile. The spectacular new building is located right next to the company's headquarters and exhibits the history of the manufacturer and its elegant products over an area of 3,600 m² and three floors. Internationally renowned planners were involved in the design of the building: While the office of Nieto Sobejano Arquitectos was responsible for the architectural design, the office of Werner Sobek took on the planning of the technical building equipment, the supporting structure and the facade. The latter gives visitors a sense of what to expect inside even before they enter the building: On the south, west and east facades, extraordinary prefabricated concrete elements show not only the well-known company logo but also a relief of the mountain that gave the company its name – Mont Blanc. In addition, the shape of the building and the special color of the facade are reminiscent of the historic packaging of the fine pens, ballpoint pens, fineliners and the like, which are shown in the exhibition.
Elaborate design, enormous size
W+P Gesellschaft für Projektrealisierung mbH supervised and coordinated the more than 60 trades involved in the construction. In doing so, it relied on the construction company G. Büter. The latter took on the role of general contractor and commissioned the precast plant BWE-Bau with the production, transport and assembly of the facade elements – a demanding task. This meant that 315 precast panels had to be created, some of which are up to 2.7 x 9.0 m in size and many of which have a geometry that is not repeated on any other panel. In addition, the team at the precast plant was faced with the challenge of manufacturing the panels with three different types of relief, which are up to 13.5 cm high in some places. Together with the necessary concrete cover of the reinforcement steel, this would have resulted in a plate thickness of approx. 7-10 cm and an even greater plate thickness for the required anchoring depth of the facade fastening. At the same time, however, it was specified that the weight of the facade should be as low as possible.
Technical details
- Size of the facade: 2,800 m²
- Facade elements: 315 prefabricated panels, each up to 2.7 x 9.0 m in size
- Relief height: Up to 13.5 cm
- Three-part structure:
-Relief structure
-3 cm thick base/redistribution plate
-webs and thickening with integrated facade suspension - Two concrete formulations:
-Lightweight concrete: for relief and base plate → reduction of the facade weight
-Normal concrete: for webs → increase of the tensile strength - Steel reinforcement: partially for webs and relief areas
- Textile reinforcement: use of solidian GRID (epoxy resin-impregnated glass fibers) to limit the crack width
Special structure
The employees of the planning office Sobek therefore decided on a three-part structure for the prefabricated facade elements. This was composed as follows: firstly the relief, secondly a 3 cm thick (base/redistribution) plate for the relief and thirdly the webs and thickenings in which the facade suspension is integrated. These should also give the plate additional stability. Furthermore, the engineers planned for two different concrete compositions within one element. The first two parts were made of lightweight concrete and normal concrete was used for the webs. This was an unusual combination, but it had several advantages: in view of the black coating of the façade elements, it was foreseeable that these would expand under the influence of heat. But thanks to the two concrete formulations, the coefficient of thermal expansion could be reduced and at the same time the tensile strength of the elements increased.
Steel reinforcement plus glass fiber fabric
And there were also differences in the reinforcement of the façade elements: While the webs and partly the relief were provided with a normal reinforcement, the panels were additionally given a textile reinforcement: the solidian GRID. This is a mesh made of epoxy resin-impregnated glass fibers. It has the advantage that it does not corrode, has a tensile strength that is up to twice as high (characteristic tensile strength > 1,100 N/mm²) as that of classic steel meshes, and is extremely light. The manufacturer has specialized in the production of non-metallic reinforcement, whereby it also supports its customers in the planning phase. It offers the solidian GRID in the standard dimensions of 6.0 x 2.30 m – whereby other dimensions and three-dimensionally shaped elements can also be supplied on request. In the Montblanc House, it was used to limit the width of the cracks and thus make it possible to design the 3 cm panels without steel reinforcement or even to design them at all. (The static proof was carried out on the basis of an unreinforced concrete slab). This meant that the weight of the façade panels could be kept as thin and light as possible while still complying with the usual rules of technology.
Photos: © Montblanc, Fotograf: Roland Halbe
