Craneway girder at a lofty height
Construction of an incineration plant with efficient solutions from MEVA
Data & Facts
New construction of the Lahe sewage sludge incineration plant, Hannover, Germany
GP Hoch- und Ingenieurbau GmbH, Hannover, Germany
Engineering and support
MEVA Schalungs-Systeme GmbH, Haiterbach, Germany
To pour the foundations, walls and ceilings of a sewage sludge incineration plant in Hannover, MEVA had to come up with safe and quick solutions. The construction of a craneway girder at a height of 21 metres was the high point of the project.
The KVA Lahe incineration plant in Hannover is expected to become operational in January 2023. The project managed by GP Hoch- und Ingenieurbau GmbH comprises three construction phases: the machine room (28.3 x 20 m), the incineration plant building (28.5 x 16.2 m) and the sewage sludge bunker (42.5 x 17 m) which can be seen from afar. The 20 m high bunker walls and a stair tower were created using slip formwork for time reasons. The craneway girder was then manufactured in situ at a height of 21 metres. To this end, the platforms for the MEVA KLK 230 climbing scaffold were pre-assembled at the Hannover and Haiterbach sites. The wall formwork concept is based on MEVA’s Mammut 350 system. To guarantee optimum use of the formwork, solutions were developed that required a minimum of assembly work during relocation.
9.6 metres – one pouring cycle
The foundations were formed using Mammut 350 and SK 80 brace brackets, which are also suitable for applications on sloping surfaces thanks to their ability to be tilted up to 15°. The industrial formwork Mammut 350 played to its strengths during the construction of the 30 cm thick and up to 9.6 m high walls of the machine room and the incineration plant building, which each had to be poured in one cycle. This saved a lot of time and was achievable due to the high fresh-concrete pressure capacity of 100 kN/m² over the entire surface. Beforehand, the optimum sizes of the gangs were determined so that they could be used for further pouring processes immediately after each pouring cycle without needing to be modified.
The slabs and concrete beams were produced using MevaFlex by the team led by foreman Jürgen Brandt. The facings rested on H20 girders, reliably supported by the MT 60 shoring tower. In the bunker it was necessary to produce slabs at a clearance height of 14.35 metres. The simple assembly – horizontally or vertically on the ground and without tools, bolts and pins – with individual parts each weighing no more than 15 kg proved to be a huge advantage. Due to its high load capacity of 60 kN per leg, the shoring tower was predestined for this project.
Use of KAB 190 as formwork platforms
While constructing the incineration plant building and the machine room, GP Hoch- und Ingenieurbau used the high-performance KAB 190 foldable working platforms as working and safety scaffolds. The wall formwork for the storeys was supported by the KAB platforms suspended on the outside of the building. Due to their high load-bearing capacity (300 kg/m²), the KAB platforms were able to be used as assembly platforms for the second slip-forming stage on the mixing bunkers at a height of 22 metres.
Craneway girder with KLK 230
The greatest challenge – at least from an optical point of view – was the construction of a craneway girder at a clearance height of 21.1 metres. The craneway girder with a total length of 120 metres, a height of 1 metre and an overhang between 1.1 and 1.6 metres completely surrounded the bunker and was poured in four L-shaped sections. GP Hoch-und Ingenieurbau did not rely on load towers here, but rather chose a more economical solution, which did not require space at ground level either. As a barrier-free working and pouring scaffold, the KLK 230 climbing scaffold supported the loads resulting from the formwork and the concrete.
The KLK 230 with its convenient, 2.30-metre-wide working platform can also be used for polygonal or round floor plans. In Hannover only right angles had to be catered for. However, it was still necessary to deal with some issues as the KLK units have to be installed with low tolerances around wall lesenes located at irregular intervals. To allow the climbing scaffolds to be used several times without time-consuming conversion work and thus achieve efficient construction progress, the optimum adaptations were determined beforehand.
GP Hoch- und Ingenieurbau GmbH was very satisfied with MEVA’s formwork solutions. Foreman Jürgen Brandt: “Together with the MEVA engineers, we found and employed practical solutions that ensured rapid construction progress and a highdegree of on-site safety.”