The new construction and extension project comprises three buildings, which are connected via a single-storey level. PORR has been commissioned with the construction of the shells of the new secondary school in the east, as well as the three-aisled central building with a sports centre and a canteen in the basement.
The sports hall will soon be sealed at the top
The walls and ceilings of the two upper floors of the secondary school are currently being completed. The construction of the mezzanine floors in the side aisles of the central building and the walls of the canteen are on the schedule. In the central nave, which will one day house the sports hall, the team from PORR Building Construction Region South recently mastered one of their biggest challenges: the delivery of the 30 m long and 16 tonne beams for the ceilings on the first floor, followed by lifting them into place. As the sports hall has a span of more than 29 metres, high-strength steel composite beams are required to transfer the load to the 6-metre-high columns. Particular attention was paid to work safety: A complete working scaffold in the sports hall over the entire area and height ensures safety during the assembly work and when concreting the beams.
Complex 3D manoeuvres in a confined space
The first hurdle was setting up the mobile crane. On the one hand, it had to have compact external dimensions in order to be able to access and drive onto the construction site. On the other hand, it had to have sufficient reach and lifting capacity to lift the long beams to this height and width.
The second and even greater challenge was the delivery of the girders on four heavy goods vehicles. "Our delivery concept was precisely planned and thought out in advance," explains project manager Marijana Karadza. "We planned and developed the delivery concept intensively over a period of two months. This included measuring every street corner and bend in the adjacent residential area over a length of one kilometre. With the many bottlenecks and parked cars, every centimetre was crucial for the convoy to get through. The idea of splitting the girders was also part of the preparations. The original plan was to supply the composite beams with chambered concrete. However, this would not have worked due to the space available on the mobile crane. So the steel girders had to be delivered separately and the chambered concrete had to be poured on site afterwards." The team spent two nights coordinating the heavy transport on site. In the end, it turned out that the theoretical concept also worked smoothly in practice. "The team pulled it off with flying colours and really good teamwork," praises Karadza.
The next milestone is the construction of the composite beams with chambered concrete in order to close the top of the sports hall as quickly as possible. The side aisles of the central building will then be raised and the final floors of the secondary school completed.
