A spectacularly shaped office building implemented quickly and cost-effectively thanks to close cooperation between ZÜBLIN and PASCHAL.

Project concept

On a 1,123 m² large plot of land to the north of the Dreisam river, STRABAG Real Estate GmbH is developing an office building which boasts stunning architecture. The design by Hotz + Architekten provides for a double cambered glass facade that gives the building the impression of a crystal. After completion, the 7-storey building, known as Schnewlin 12, will include a 2-storey underground garage.

PASCHAL played a significant part in the rapid progress of construction.

An additional special feature is that the developer and investor STRABAG Real Estate will not rent the space as is typical for office buildings, but will instead sell it for part-ownership. The project has been so successful on the market that, at this moment in time during the construction process, more than 50% of the available units have already been sold.

Realisation of the building

On a 1,123 m² large plot of land to the north of the Dreisam river, STRABAG Real Estate GmbH is developing an office building which boasts stunning architecture. The design by Hotz + Architekten provides for a double cambered glass facade that gives the building the impression of a crystal. After completion, the 7-storey building, known as Schnewlin 12, will include a 2-storey underground garage.
An additional special feature is that the developer and investor STRABAG Real Estate will not rent the space as is typical for office buildings, but will instead sell it for part-ownership. The project has been so successful on the market that, at this moment in time during the construction process, more than 50% of the available units have already been sold.

A complete slab table form, constructed from the GASS aluminium shoring system with top-lying and permanently mounted H20 girders, with the special lifting fork that reaches across 2 floors.

Structural creation

Construction of the shell began in July 2016. The concrete construction work in the sixth floor, with the exception of the reinforced concrete ceiling slab with a circumferential fascia, was completed by mid of December. On visiting the construction site in the middle of December 2016, shortly before the completion of the reinforced concrete work, Lukas Heibel, ZÜBLIN construction manager and foreman Dieter Billharz praised the cooperative partnership. Dieter Billharz said "When forming and scaffolding, it is not only the hardware that is important, but also the systematic planning, the thinking and the ability to react flexibly. Even if the project and construction processes are pre-planned in great detail, there are unpredictable challenges that have to be reacted to quickly. In such situations, the cooperative partnership with construction specialists with great practical experience, such as the PASCHAL team, is of great value."

Formwork and shoring in a system with spectacular designs is no problem for PASCHAL.

For the complete shell with a gross volume of 14,500 m³, 2,500 m³ of ready-mixed concrete was processed.
The following was used for the formwork and shoring: for the formwork of the individual and strip foundations, around 200 m² of Modular. Some of the reinforced concrete wall sections along the railway line were formed with "Modular", as it was not allowed to use cranes here. The reinforced concrete wall panels were created from floor to floor with 340 m² of LOGO.3. 55 m² of TTR circular trapezoidal girder formwork were used for the creation of circular walls and parapets in the area of the entrance and exit shafts. 7,150 linear metres of H20 girders and 1,500 props of the load groups B/D 25; B/D 30 and B/D 35 provided reliable support for the prefabricated slab. 10 reinforced concrete supports with different cross-sections were built with just one Grip column formwork. 18 inclined and 40 vertically standing circular columns with external diameters of 30 cm and 50 cm were built with 20 linear metres of circular column formwork.
66 linear metres of foldable KBK 180 climbing platform served as working platform floor by floor.

On the facade that is oriented towards the railway line, for the fastening of the KBK foldable platforms, the 8 cm deep facade recesses, that had to be integrated in the reinforced concrete shell for optical reasons to mount the "blind window units", were bridged in a system-integrated manner.
A couple of specialised solutions were designed and manufactured in steel in Steinach to adapt the rented formwork and shoring systems.
In order to allow the 18 inclined reinforced concrete circular columns with an external diameter of 40 cm to follow the double-cambered facade surface exactly, the PASCHAL formwork experts produced three different angled circular column feet fitting elements.
As all of the slabs were executed using prefabricated slabs, no classic slab formwork was used. In order to safely dissipate the dead weight and the weight of the top concrete layer during the setting period, PASCHAL designed nine slab table forms using the GASS aluminium shoring system with dimensions of 1.80 x 3.00; 2.40 x 3.00 and 1.80 x 1.20 with up to 6.00 long main girders for the projecting floor slabs.
Special lifting forks that reached over two floors were used to move the slab table form. In this way, the load-bearing slab table form and props could remain in the subjacent floor over which the top concrete layer was introduced without disturbing the construction process.
Roof waterproofing work, facade construction, interior construction and the installation of the building technology are set to follow and the construction managers Lukas Heibel and Dieter Billharz remain fully committed to meeting the handover deadlines.

 
In the foreground, one of 18 inclined reinforced concrete circular columns that have been adapted to the double-cambered facade surface. Furthermore, PASCHAL produced three circular column feet with three different inclinations. Foreman Dieter Billharz inspected the exact inclination of the columns before the concreting process.