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Hünnebeck's Novel Steel Frame Table Form Boosts Efficiency

Novel steel frame table form boosts efficiency
Successful assignments

It cuts labor costs by about a quarter, makes do with half as much crane time and is capable of slashing transport and logistical costs by up to 70 percent. These are the selling points of Topmax, the world’s first steel-frame table form, manufactured by Hünnebeck. But have the first practical assignments lived up to these claims? In three entirely different projects in Hamburg, Berlin and Dresden, the innovative product has been put through its paces in daily use. The verdict: Surfaces can be shuttered quickly with Topmax table forms, and completely without nails.

Transfer time: 0.16 h/m²
Building contractor Otto Wulff (Hamburg) created about 15,000 m² of slab surfaces with Topmax during the construction of Hamburg’s "CardioCliniC". The large, uniform slab surfaces of the five-floor complex plus an underground parking garage and a sublevel, the limited storage space and the demand for extremely rapid construction combined with the builders’ desire for an extra-simple system created the ideal conditions for the use of Topmax, the new table form. As things turned out, this innovation with its maintenance-free slim steel frame and its durable plastic form lining was particularly conspicuous for its extremely short transfer times of 0.16 h/m² during this project. What’s more, the novel formwork unit in fact took up gratifyingly little of the extremely limited storage space.
This is due to the only 12 cm thick, hot-dip galvanized steel frame enclosing the easy-clean plastic form lining. The minimal thickness of the 10 and 13 m² table forms enables highly space-saving stacking. The extremely smooth form lining is safeguarded from damage by a permanently attached stacking protection system and does not need to be replaced at any time during the construction process. In fact, the Topmax table form requires little cleaning between assignments. The plastic form lining and the heavy-duty, powder-coated steel frame attract little dirt, and any residues are easily removed.
New products come in for especially close scrutiny, which is why the managers of the clinic project made a point of documenting the actual shuttering and stripping times, quantifying them at "0.16 h/m², a figure that can even be improved on". The designers of the unique table form see this as vindication of their strategy. The positive appraisal is confirmation of the carefully considered system details which add up to the marked optimization of all work processes. Among them, for instance, is the specially developed folding head with its self-securing pin and engagement mechanism which ensure rapid assembly and 180° leg mobility.
There are various ways of moving the table form on the construction site. The crane-independent Topmax Lift, the 1,250 kg crane-operated transfer fork, the electrically powered Topmax carriage and the individually fastenable crane sling attachment points – always adapted to the specific conditions on site – permit rapid transfer. Furthermore, two Topmax table forms can be connected with the centering clamp to yield 26 m² of shuttering surface and transferred in a single crane lift together with their legs and fall protection rails.
The otherwise time-consuming creation of adjustment formwork and stop-ends has also been solved within the system. For larger adjustment areas and infills and for the shuttering of corner columns, the Topmax table forms are connected with the centering clamp to steel frame panels of the Rasto/Takko System. For smaller adjustment areas, there’s squared timber. It is even possible to easily combine Topmax table forms with the beam-free Topec slab formwork system, as the Hamburg project has demonstrated. This is made possible by a special system component, the so-called Topec-Topmax head, with which the table forms can be connected to Topec formwork.

Rapid shuttering with timber holder and end slide
During the construction of a hotel in Dresden’s "Altmarkt", the builders are much impressed by the Topmax timber holder, Topmax end slide and the integrated fall protection. A total of 26,400 m² of slab surfaces are being poured with the Topmax table form system during the erection of this building complex comprising an underground parking garage, two sublevels and seven above-ground levels. Rapid progress and good-quality concrete are obligatory, as the building fabric is due for completion after only 10 months for construction.
At peak times, about 2,000 m² of Topmax are being kept available, but space and hence storage capacity are also in short supply on this site in Dresden’s inner city – and this is where the slim table forms pick up points. The space is in fact so confined that it is impossible to use the transfer fork. However, this potential problem is solved by the crane sling attachment point, which can be fitted at any point along the continuously perforated table form profile.
The rapid pace of shuttering has been facilitated on the Dresden construction site by the Topmax timber holder which enables smaller gaps between the table forms to be easily filled with wood. "The holder is simply hooked onto the table form profile. And then the timber is inserted and covered with the form lining," says foreman Matthias Kaufmann describing the speed of handling that conventional table forms cannot match.
For the time-saving shuttering of all the end faces, the builders are using the Topmax angle together with the end slide and clamp. The angle is fastened to the table edge profile with the centering clamp and centering nut. The end slide pushed over them can be adjusted to any height and depth and fastened with the clamp. At the same time, the multifunctional end angle will also receive the Protecto edge protection system in order to create a stop-end with fall protection.
Which brings us to another feature of the Topmax system that has had a positive impact on the Dresden hotel project – the integrated fall protection created by simply attaching the Protecto edge protection system to the Topmax table form. The Protecto post holder can be attached at any point to the table form’s all-round profile, thus quickly safeguarding the parts of the slab with a risk of falling.

Topmax at the BBI Airport
Because all the challenges of shuttering slab edge surfaces are mastered by Topmax within the system, the novel table form has also been selected for the large construction project for the new Berlin Brandenburg International Airport (BBI), the hub serving Germany’s capital. For the construction of the 350 m long north pier with its twelve passenger boarding walkways, it is serving as high-speed formwork equipment for the joist-free slab edge areas on levels E0 and E1 (roughly a third of the total slab surface of roughly 15,000 m²).
Only 60 Topmax table forms (1.8 x 5.4 m) plus accessory equipment are available on site and are accomplishing their assignments at lightning speed thanks to their rapid transfer. The site team is unanimous that this is a high-speed system for outstanding concrete surfaces. "All the otherwise problematic aspects of edge table forms have been overcome on the Topmax system," says project management in praise of the new table form. "Projections, fall protection, stop-ends and retainers with wall struts – all these can be created with little effort." This is joined by its ease of combination with the Topec system, which is being used to shutter the other slab surfaces.
Highly commended, the Topec system has elicited praise from everyone concerned during its first practical assignments. Along with rapid shuttering and transfer, low space requirements and minimal cleaning effort, the new table form impresses users with its ingenious and time-saving system features. Practitioners appreciate this attention to efficiency, and the developers are glad to hear it.