Science Center “Phaeno”, Wolfsburg, Germany
The “Phaeno” science centre in Wolfsburg is undoubtedly a masterpiece of concrete technology. Glass as a material was also pushed to the limits of what was feasible – for example, the entrance to the science theatre is encased in conically curved insulating glass mounted as structural glazing.
Zaha Hadid’s bold design rests on ten conically shaped concrete volumes, like feet, in which different functions are integrated. One of these feet forms the entrance and foyer of the 230-seat science theatre. At this access situation, the concrete skin breaks open and turns into a glass membrane. The approximately 150-square-metre glass surface precisely captures the curvature and three-dimensional shape of the foot. This and the desire for invisible installation of the glazing, which is strongly inclined outwards, placed the highest demands on the planning, assembly and production of the structure.
Project data
Architect
Zaha Hadid Architects, London
Consulting architect for glazing
Niessink Engineering GmbH, Edemissen
Execution
Glasfischer Glastechnik GmbH, Isernhagen
Glass supplier
Schollglas Technik GmbH, Object Center, Heynitz-Lehden
Different curvatures for flowing building contours
The insulating glass was manufactured by Schollglas Technik Sachsen, the installation was carried out by Glasfischer Glastechnik, Isernhagen. Due to the different curvatures, the panes were adapted to the outer contours and thus to the free-flowing edge of the concrete cut-out with minimal tolerance. For example, none of the glasses is right-angled, the radius of curvature changes over the height and from glass element to glass element.
CAD files and shell dimensions precisely determined on site served as the basis for the deformation of the panes. The panes were made of toughened safety glass (inside) and laminated safety glass (outside) by hot forming. Due to the pairwise deformation of the outer and inner pane, the bending deviations remain minimal. Finally, SCHOLLGLAS assembled the panes into insulating glass using a manual process. The flat panes differ only slightly from the curved elements in the thickness of the inner pane and the space between the panes, so that the required optically uniform image is created. Hence the consistently same, pyrolithic metal oxide treatment of the outer lenses with K Glass coating. This type of coating, which is mechanically very resistant, is also suitable for hot forming with its special thermal loads.
Invisible and flush mounting
The insulating glass was mounted on the substructure made of round steel tubes exclusively via the ESG inner pane equipped with two or four foils. The GEWE-tec® system is used for this purpose, which invisibly engages in the edge bond of the insulating glass and thus enables the desired flush glazing. The outer pane is only held in place by the spacer and the glue to the inner pane. The GEWE-tec® system can also be used to cope statically with extreme loads, such as those caused by the sloping cantilevered construction.
Complicated assembly without disrupting ongoing operations
The panes had to be installed during ongoing museum operations, as the realisation of the science theatre did not take place until about a year after the opening of the building. The assembly itself was particularly difficult, which actually had to be carried out overhead, but there was no way to attach the glass from the outside. This led the fitters from Glasfischer Glastechnik to consider lifting the panes from the inside using a suction battery. For precise positioning, the lenses always had to be lifted at the center of gravity. There were virtually no possibilities to manually readjust the lenses. Because there are only a few attachment points per glass, no stresses were allowed to occur that could have led to breakage and time-consuming reproduction of the individual pieces.
The bottom line is a high effort for a relatively small area, you could say. However, the curved glass plays an important role in the sense of the coherence and consistency of the overall project.
