On the former North Station area, the "Schwarzatal" non-profit real estate developer is currently realizing a very special housing project. Under the title "A residence with everything!", a total of 91 residential units are scheduled to be completed by autumn 2013 – located in a rental apartment facility along with a residential home for the "Association for a Sustainable Way of Life." The use of modern and efficient formwork systems for the walls and slabs ensured that the very tight completion deadline of only 10 months for the building shell could be met.
On the area that was formerly Vienna´s North Station, around 10,000 apartments and 20,000 jobs will eventually be created over the next few years. The urban development design of two eight-storey residential buildings with a total of 91 housing units includes generously equipped facilities with balconies and loggias as well as concrete cast in place. In this connection, increased architectural concrete requirements were to be met for the walls and undersides of the balconies; in addition, the 10-month construction schedule for the structural work was extremely tight. Through the use of the PERI formwork systems, MAXIMO and SKYDECK, the walls and slabs could be formed much faster. In conjunction with well thought-out cycle planning, on-site material requirements remained easily manageable.
The time savings achieved with the MAXIMO panel formwork resulted, on the one hand, from the use of the MX tie technology with ties installed from one side and consists mainly of the MX tie and MX wingnut. In the process, the MX wingnut is fixed just once at the start of operations to the primary formwork and then the MX tie can be screwed in through the closing formwork into the wingnut – thus the anchor can be operated by one person and from one side during each forming operation. The conical-shaped tie rod does not require any spacer tube and cone which saves on materials as well as further time and effort.
On the other hand, the systematized arrangement of tie points accelerated forming operations with MAXIMO. The tie points are centrally-arranged and anchors at the edges are not required – this reduces the number of ties and therefore saves valuable time for each casting segment. Furthermore, every tie hole in the MAXIMO panels is used: this means that it is not necessary to ensure that any unused tie points are sealed. This eliminates possible sources of error and subsequent rework.
In addition, the well thought-out positioning of the tie points in the MAXIMO panel formwork results in a regular joint pattern – both horizontally and vertically. In this way, attractive concrete surfaces could be achieved for the walls of the residential buildings.
The storey slabs were formed systematically with the lightweight SKYDECK panel slab formwork. The recurring assembly sequence and easy handling accelerated the shuttering and striking procedures. The practical size and low weight of the individual aluminium system components ensured fatigue-free working operations. Through the use of the drophead system, the panels and main beams could be used at an early stage for the next concreting cycle. This considerably reduced on-site materials requirements.
The design of the balconies presented a particular challenge during the planning process. For the undersides, architectural concrete quality was required; in addition, the balcony slabs featured an offset arrangement on each storey. For forming the balconies, PERI engineers selected MULTIFLEX girder slab formwork supported by MULTIPROP shoring towers. As a result, the increased architectural concrete requirements could be comfortably met and, in coordination with the site management, the cantilevered slab formwork simultaneously served as circumferential working scaffold.