NOEalu L formwork system combines low weight with high strength
Teaching and research at UvA presently takes place in 85 different buildings. These activities are to be concentrated in four city campuses. The UvA University Library building will stand on one of these, the Universiteitskwartier or the University Quarter. This will entail the renovation of the Binnengasthuisziekenhuis, a former hospital, and the addition of a new wing. A large 950-bicycle parking basement is provided to increase bicycle use and motivate as many people as possible to travel on two wheels. NOE-Bekistingtechniek, the Dutch subsidiary of NOE-Schaltechnik, Süssen, developed a special formwork solution for the internal and external walls of this basement.
The Binnengasthuis site in the University Quarter has served many different purposes over a long history going back to the Middle Ages. This was where the city’s Old and New Convents once stood. The area has been home to a convent, a hospital, a museum, residential housing and a university. The University of Amsterdam was founded here in 1632 as the Athenaeum Illustre. Two historical buildings of the former Binnengasthuis Hospital, the Second Surgical Clinic and the Nurses’ Quarters, are now to be renovated and extended with a new wing to form a single library building. The eye-catching elements of the design are the spectacular glass roof and the new wing. Precision will be crucial for the construction of the basement and sunken atrium under the existing building.
The basement is being built by civil engineering contractors Van Hattum en Blankevoort & Volker Staal en Funderingen. The building has undergone many alterations and extensions over the years, which has resulted in complications for the new basement. To allow a basement to be constructed under the existing building, the historical structure had to be supported on piles and temporary steel beams inserted to carry the weight of the entire building. Then the original foundation beams were removed and a new floor installed at ground floor level. With the temporary loadbearing construction in place under the future library, the basement could then be excavated to a maximum depth of 5 m and its floor slab concreted. All the internal and external walls between these two floors then had to be constructed. These walls followed the shape and position of those in the current building.
Easy-to-handle and resilient formwork system
Van Hattum en Blankevoort looked for a formwork system that was not only easy to handle and simple to use but also designed to resist concrete pressures of up to 65 kN/m2. NOE-Bekistingtechniek was able to offer the NOEalu L formwork system to satisfy both requirements. Because of its light weight, this aluminium wall formwork is easy to use yet it can cope with high concrete pressures. NOEalu L was developed to be a system that could be moved manually and capable of resisting the required fresh concrete pressure during construction.
Pumping in situ concrete
Placing the concrete on site presented a challenge. Normally, in situ concrete is poured into a form through its open top, but that was not possible here because the top and bottom of the formwork were closed. The contractor therefore opted for self-compacting, pumped concrete. NOE-Bekistingtechniek devised a formwork concept in which the wall panels had strategically positioned holes to allow concrete to be introduced at heights of 0.5 m, 1.5 m, 2.5 m and 3.5 m. The concrete pump was connected to these filling points with a shut-off valve to allow the concrete to be placed in layers approximately 1 m deep. The self-compacting concrete mix was designed so that the concrete would flow over a distance of 10 m in both directions from the holes. More holes were made in the formwork at the ends of each length of wall poured to allow the displaced air to escape.
With the new foundation and basement walls almost complete, the temporary steel beams can be removed one by one from the building. This sizeable amount of additional floor area provides enough space for not only basement bicycle parking but also the building services equipment, the library counter (issue and return) and a sunken multipurpose atrium. The UvA University Library is scheduled to open in 2023.