During the construction of the new National Archives building in New Zealand, “Te Rua Mahara o te Kāwanatanga,” there was a special requirement for filling the spaces between the rails of the mobile shelving units.
The heights of the planned screed were calculated at a maximum of 30 mm and the building was designed accordingly in terms of statics. However, as up to 60 mm of screed was required in some areas, a solution was sought to reduce weight.
VELOSIT SC 241 was installed using a pneumatic pressure conveyor from IMER (Mover 270eb). An Inomat continuous mixer 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.
Height adjustment is relatively easy to achieve with flowing screed. For the VELOSIT SC 241, which was installed at earth moisture level, a laser-controlled Capa Floor Master 130 robot was used, which allows the screed to be leveled with millimeter precision. The surface was then leveled to the height of the rails with a PMMA coating.
With the lightweight screed VELOSIT SC 241, 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 was installed over an area of 2,000 m², while the high-strength cementitious self-leveling screed VELOSIT SC 244 was used over a further 6,500 m² where only 30 mm was required.
The project was completed over a total of 12 months and was a logistical challenge. A total of 28 sea containers had to be timed so that there was always enough material on 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 ways.
Architecturally, outstanding solutions had to be implemented because the building could experience up to 120 cm of movement in the event of an earthquake, but at the same time was connected to the National Library by a bridge.
