Rising some 43 storeys and topping out at 148m, the KolnTurm will be Cologne's tallest office complex. Its design is unusual too, reflecting the variety of different uses to which its 33,00m 3of floor space will be put. The building will house individually customised office spaces, apartments, a business hotel, plus numerous services and a lobby area.
Up to the 29th floor the quadratic floor plan, 28.75m by 28.75m, leaves all fitting out options open. Rising through the centre of the building is the four-sided core housing lift and service shafts, lift foyers and a stairwell. Above the 29th storey, there are floors on only two sides of the core.
The floor slabs are supported on reinforced concrete columns along their outer edge.
Construction was made difficult because the area around the site was heavily built up and with room for only a single crane and one access road for the entire complex. From the outset the contracting joint venture, Hochtief and Heitkamp had in mind a kind of 'forming machine' that would also carry the concrete placing boom.
This was achieved by a combination of a Doka self-climbing platform SCP for the core structure, Doka's SKE 50 automatic climbers for the facade and Dokaflex formwork for the floor slabs. After dismantling, the Dokaflex is placed in the automatic climbers suspended from the outside of the structure and hitches a ride up to the next storey. This combination makes it possible to pour walls and floorslabs in a single operation and has given rise to entirely new working methods and a weekly cycle for the core and the floors.
Formwork is climbed on Monday and erected and the reinforcement placed on Tuesday and Wednesday. On Thursday the high-strength concrete is poured using a Putzmeister placing boom clamped to four Doka automatic climbers beneath the platform and on Friday the formwork is struck, ready to begin the cycle again.
E-mail: Heinrich.Eker@doka.com Fax: 43 7472 64430