Parabolic walls, vibro-insulators, black concrete, hand-made formworks of wooden strips, huge rubber moulds, four tower cranes and more than 150 workers at the construction site – this is how Warbud builds the new PLN 265 million seat of the National Polish Radio Symphony Orchestra (NPRSO).
After five months and a half when the works have been started, the prime contractor’s strong commitment to erect the building on time and on standard is visible. “First elements of the foundation slab we have laid on 28th of March this year, two weeks after the groundbreaking had taken place. Now, the whole investment is about 35-40 percent done” – said Grzegorz Strzelczyk, construction site manager at Warbud.
160 people are involved in the works every day. The number will be increased to about 500 when the outfitting is started. The builders have already raised the underground storey mostly designed as a parking space and are currently progressing with the ground and the first floors of the new venue. “The scale and technical complexity of the project has been unprecedented in Poland” – Grzegorz Strzelczyk adds. “The whole construction process has to be up to the architectural and acoustics standards prepared by the designers. For example, when carpenters finish hand-made formworks of each part of the parabolic external walls of the great concert hall, the head designer commissions the formworks at first and only then the concrete can be poured.”
The parabolic walls’ wooden formworks made of different-sized strips are covered by black concrete. Before that the strips have to be arranged according to specific sequence including the length and width. After the concrete is dried and the formworks are dismantled, the wall shows a subtle wood pattern. The process is very complex and had to be divided into a number of stages. “The formworks require best qualifications and involve great accuracy” – Grzegorz Strzelczyk explains. Before Warbud decided to pour the formworks with concrete in the building, several attempts on test walls were made at the construction site. The same kind of tests were applied for internal walls of the great concert hall – the irregular walls’ pattern is got by huge rubber moulds inside of which the natural-coloured concrete was laid. Here the walls will be painted black.
The external walls of the elevation are being already mounted and these are made of prefabricated elements prepared at the construction site. Then, the installed elements will be covered with the elevation of clinker bricks, aluminium and glass.
The acoustic quality of the broadcasts and recordings made by the musicians has to meet high-level requirements demanded from the first stage of the construction work. For example, both the great concert hall and the chamber hall are being placed on vibro-insulators to prevent transmission of noise and high frequency vibration to the halls. Representatives of Warbud emphasizes the unique solutions adopted in the project.
The new venue of the music lovers of the National Polish Radio Symphony Orchestra will be put up thanks to 22 000 cubic meters of concrete and 4 200 tons of steel. Four tower cranes reaching from 43 to 56 meters with a jib length of 60 meters each are helping to erect the building. The consortium of three firms – EBUD, LTT and Warbud as the leader – will build the venue for PLN 234,9 million (estimated total cost of the undertaking: PLN 265 million). The head designer of the building is Tomasz Konior, Nagata Acoustics – the world’s famous acoustic company from Japan – is responsible for the acoustics.
The building is being erected along Roździeńskiego Av. near the “Spodek” sport and exhibition hall.