The building was designed by the French architect Dominique Perrault, who gained international recognition with the National Library in Paris. It comprises an entirely new urban district with a diverse range of functions: offices, a four-star hotel, apartments, a sky bar, a public open space, restaurants, and a fitness centre.
In their planning, the developers put great emphasis on sustainability, which means that the DC Tower 1 is designed to meet the energy and sustainability requirements that the EU Commission places on a green building.
One of the challenges of the project was the construction of a pure reinforced concrete structure, which meets the highest static requirements, while optimising form and function.
To meet the construction requirements of such a large, elegantly-designed building, the client used CRH cement products as well as the expertise of the company’s “Technical Competence Centre”. High-strength concrete, produced using cement that is characterised by good early and final strength and good water retention capability, was chosen. This was particularly important for such a tall building, as the concrete had to be transported over long distances using stationary pumps.
Ensuring processability of the fresh concrete – in addition to its high-strength quality – was also important, which is where CRH’s technical expertise was required to ensure the right additives were used. For this project, CRH worked with the additive manufacturer Mapei-Betontechnik, who delivered the retarder and the air-entraining agent as well as the flow agent. Some of these products were used in the gigantic floor plate for the building, which was four metres thick.
To secure the 250,000-tonne tower, reinforcing steel with a diameter of up to 40 millimetres had to be installed, as well as 12,000 cubic metres of concrete. This was only feasible by working non-stop for five days, ensuring the heat of hydration did not rise too much, creating a risk of shrinkage cracks.
CRH’s products, expertise and collaborative working style were vital in meeting the technical challenges of this project and delivering a tower that will shape the skyline of the Austrian capital for decades to come.