Chimney Tables for thyssenkrupp Steel
Duisburg, Germany
Strong and safe: A mobile base made from Doka UniKit and Ringlock
Mobile Doka UniKit shoring towers combined with the new Ringlock modular scaffolding form a strong team for the construction of walking beam furnaces for thyssenkrupp Steel.
Massive table tops with a ceiling thickness of 2 m are to be erected to build gigantic chimney tables - at a height of almost 14 m. To cope with the enormous loads, Mainka Bau GmbH & Co. KG is relying on a formwork solution from the Doka specialists. They literally designed a ‘mobile base’: a mobile unit consisting of Doka UniKit shoring towers and Doka Ringlock modular scaffolding, which simultaneously ensures safe load transfer and protected working areas.
Construction
Industrial chimney tables for two new walking beam furnaces
The challenge
Enormous loads to be transferred, complex statics, safe working environment at great heights, high material requirements, tight timing.
Solution
Mobile unit consisting of three UniKit shoring towers equipped with Doka Ringlock, enabling both safe removal of the loads and a protected working environment.
Engineering XXL
Thyssenkrupp Steel is one of the leading manufacturers of flat carbon steel and stands for innovations in steel and high-quality products for the most demanding applications. Steel employs a good 26,000 people and, with an annual production volume of around 11 million tonnes of crude steel, is the largest flat steel producer in Germany. The facilities in which pig iron and then flat steel are produced are correspondingly gigantic: the chimneys of the production facilities rise up to 250 m into the Duisburg sky - they are among the highest in the whole of Germany. The Doka engineers also become acquainted with the enormous dimensions at thyssenkrupp Steel when they receive an enquiry from Mainka Bau GmbH & Co. KG - and table is the key word: huge chimney tables are to be built as part of new furnace systems, onto which the steel chimneys will then be placed. Six concrete pillars, each almost 14 m high, will support a table top with a ceiling thickness of 2 m and an area of 190 sqm - that's about 2.5 badminton courts. The Lingen-based construction company is calling on the expertise of Doka's formwork experts to produce these man-high table tops.
"You can imagine the enormous loads which are connected with such dimensions. That's why we had to think in XXL format when developing a formwork and shoring solution,’ says Martin Crames, the project engineer in charge at Doka. But it's not just the safe, precise load transfer that poses a real challenge when it comes to formwork planning. There is also the question of how to realise the huge areas to be formed at such a height with the most economical use of materials and resources within the construction schedule. A challenge made for the shoring professionals from Doka.
Roeland Bekhof | Formwork Preparation | Mainka Bau GmbH & Co. KG
"Right from the planning stage and also later on the construction site, the collaboration with Doka was simply excellent. This mobile UniKit unit was a real game changer for this project: innovative, economical, time-saving. And thanks to the permanently integrated ringlock platforms, our people always had a safe working environment exactly where we needed it."
Strong and safe
Although feasible in principle, the Doka engineers have ruled out a classic shoring substructure because of the high material costs involved and the limited flexibility when moving between cycles. Instead, the shoring experts turned to the new Doka UniKit heavy-duty construction kit and used it as the basis for developing something unprecedented: a gigantic heavy-duty unit consisting of three 13.7 m high, six-legged UniKit shoring towers 1000. The frame of the towers is constructed from components that are delivered to the site prefabricated and assembled on site by the Doka formwork pre-assembly team in just a few steps using the linkable yoke beams. ‘This creates a continuous frame and gives us a self-contained component that is extremely rigid and therefore highly stable,’ says Martin Crames, explaining the solution.
To ensure a safe working environment as well as load-bearing capacity, the Doka engineers also used the new Ringlock system and fitted the UniKit structure with a ‘full set’ of working scaffolding inside, which also serves as an access route and assembly aid for the site team. The included standard perforated steel decks are used to quickly and easily create closed levels on which the team can move safely at all times and carry out work on the slab formwork. The safety platforms also arrive at the construction site pre-assembled and are assembled there with the UniKit frame to form the finished tower: plug and play.
A colossus on wheels
As if that wasn't enough, the planners have gone one better: the UniKit+Ringlock unit is designed as a kind of mobile formwork carriage: The 100 tonne colossus can be moved as a whole to the next construction section using a cable winch via roller blocks borrowed from the composite formwork carriage system. There is no need for time-consuming dismantling and reassembly. With this customised ‘mobile base’, the entire ceiling surface for the fireplace tables can be placed and formed in a time- and material-saving manner. Classic Staxo 100 shoring is used laterally between the pillars.
In the meantime, ‘the table’ has been set, meaning that the table tops have been concreted. Looking back, Mainka site manager Roeland Bekhof is just as impressed by the ingenuity of the Doka engineers as he is by the partnership-based co-operation - both in front of and behind the scenes: ‘Right from the planning stage and also later on the construction site, the cooperation with Doka was simply excellent. This mobile UniKit unit was a real game changer for this project: innovative, economical, time-saving. And thanks to the permanently integrated Ringlock platforms, our people always had a safe working environment exactly where we needed it."
Project data
Year of completion
2024
Project duration
Januar - März 2024
Country
Germany
ZIP Code
47166
City
Duisburg
Contractor
Mainka Bau GmbH & Co. KG
Building data
Table height
13,70 m
Table top surface
190 m 2
Table top thickness
2 m