A construction site featuring fair-faced concrete of ultimate quality (class 4) poured to perfection – there’s no such thing is the common opinion of many experts. They’re wrong though! The extension of the Max Planck Institute in Mülheim, Germany, testifies to the contrary. If the material is right and everyone involved pulls together, top-class fair-faced concrete can be produced – without the need for time-consuming surfacing and finishing work.
It was an exciting moment when the 20 m tall foyer wall in the new office building on the Mülheim construction site of the Max Planck Institute for Chemical Energy Conversion (MPI CEC) was struck in mid-July. When foreman Anthony Kealey from the North Rhine-Westphalian construction company Derichs und Konertz instructed his team to dismantle the special Hünnebeck formwork, it was clear after just a few simple steps: the careful planning and preparation of the wall in fair-faced concrete top quality 4 had led to a perfect result (see Figs. 1 and 2). All requirements for the surface finish and appearance were met. In addition to this foyer wall, the three stairwells in particular (see Fig. 3) with their horizontal joints and neat arrangement of ties are among the visible highlights in the two new laboratory and office buildings.
In the meantime, the construction site in both buildings has produced a total of around 2,400m² fair-faced wall surface – and both architect and client are well satisfied with the result without any ifs or buts. Only unique one-off items of formwork were used on the Mülheim construction site to produce the fair-faced concrete surfaces „of particularly high architectural significance.” These are H 20 beam elements developed by the Hünnebeck team of experts, coordinated with the architect, manufactured in the company’s own special formwork shop and delivered to the construction site ready for use. Around 550 m²special formwork is used in section A and around 850 m² in section E in order to be able to pour the concrete most cost-efficiently. Betoplan Top MF from Westag & Getalit serves as the form lining. According to Hünnebeck’s one-off formwork planners, this large-surface formwork panel made of veneer plywood with melamine resin film coating and edge sealing is regarded as „currently the best formwork lining available on the market” for top-quality finishes.
High quality, carefully manufactured formwork elements are of course a prerequisite for achieving a high-quality concrete surface in SB4 quality. But what also counts is early, detailed coordination between all parties involved. It is not without reason that the DBV bulletin Sichtbeton (fair-faced concrete) recommends the formation of a „fair-faced concrete team” that brings together the client, architect, formwork planner, building technician, building contractor etc. right from the planning process. In this way, it is possible to determine in detail as early as possible what exactly is desired and how this can be achieved. This protects against unpleasant surprises and ensures a smooth construction process.
„This was a really good job carried out on this construction site,” says the Hünnebeck engineer from Technical Project Development, who was responsible for formwork planning on this project. He accompanied the construction site work from the very beginning: „We enjoyed very constructive cooperation in all phases.” Tim Schäfer, site manager at Derichs und Konertz, also confirms this: „The construction site ran smoothly, and this is by no means a matter of course – especially when coping with such challenging demands. The result is an outstanding reference project in fair-faced concrete.
The Max Planck Institute for Chemical Energy Conversion (MPI CEC) in Mülheim conducts basic research on all chemical processes that play a role in the storage and conversion of energy. This has been and is an important area of research accompanying Germany’s „energy turnaround,” so that it was decided to expand the institute considerably in terms of space and personnel. In addition to the extensive conversion of the existing buildings, four new buildings with a total floor space of 4,500 m² are planned. Derichs und Konertz are currently constructing an office building (Section A) and a laboratory building (Section E) – both with three upper floors plus basement. In addition to the special formwork for the exposed concrete surfaces, Manto large-area formwork was used to form external walls, supports and columns. Topec modular formwork facilitated fast shuttering times.