For the new construction of the National Archives in New Zealand “Te Rua Mahara o te Kāwanatanga”, there was a special requirement for filling the areas between the rails of the mobile shelves.
The height of the planned screed was calculated at a maximum of 30 mm and the building was statically designed accordingly. However, as up to 60 mm of screed was required in some areas, a solution was sought to reduce the weight.
VELOSIT SC 241 was installed with a pneumatic pressure conveyor from IMER (Mover 270eb). A continuous mixer from Inomat and a Putzmeister S5 were used for the flowing screed surfaces. Both products were installed in combination so that the rails protruded 2 mm from the substrate.
The height adjustment is comparatively easy to achieve with the flowing screed; a laser-controlled Capa Floor Master 130 robot was used for the wet-in-place VELOSIT SC 241, which enables the screed to be removed with millimetre precision. The surface was then leveled to the height of the rails with a PMMA coating.
With the VELOSIT SC 241 lightweight screed, it is possible to create a C35 screed and at the same time save 40% in weight compared to a standard cement screed.
A total of 190 tons of VELOSIT SC 241 were installed over an area of 2,000 sqm , with a further 6,500 sqm of VELOSIT SC 244 high-strength flowing cement screed, where only 30 mm was required.
The project was realized over a total of 12 months and was a logistical challenge. A total of 28 sea containers had to be clocked in so that there was always enough material on the construction site, which was an exciting task given the 8-week transfer time from the VELOSIT plant in Belle, East Westphalia.
The project is a landmark in New Zealand in many respects.
Architecturally, outstanding solutions had to be implemented because the building could move by up to 120 cm in the event of an earthquake, but at the same time was connected to the National Library by a bridge.
