Mülimatt Aare Bridge, Brugg

The Aaresteg is an attractive local and regional route for slow traffic connecting Brugg and Windisch to the nearby recreational areas and rerouting much of the cycle traffic from the main cantonal roads.

The Aaresteg is an attractive local and regional route for slow traffic connecting Brugg and Windisch to the nearby recreational areas and rerouting much of the cycle traffic from the main cantonal roads. The bridge was designed as a stress ribbon bridge with a total length of 182 metres, making it the longest bridge of this type in Switzerland. The pre-stressed in-situ concrete slabs are wide enough for pedestrians and cyclists together and work in conjunction with four flat steel bands along the bottom. The bridge slabs are supported on two, massive abutments and three steel, frame-shaped intermediate supports. The slab sections have widths of 30 m, 78 m and 35 m.

Construction method: The shuttering was suspended on the already spanned flat steel bands. In order to reduce deformations during the concrete laying stage, the slabs were pre-tensioned before adding the side shuttering to create a constraint. The shuttering was made watertight by offsetting the placement of the two-layer shuttering boards. It was added to the main section over the Aare using a mobile work platform. To hold the supporting structure in stress balance, the concrete was laid in-situ in a single pour. 560 m2 of concrete surface then had to be treated within a few short hours with the greatest care. To achieve this, five teams with electric screed rails were employed simultaneously. Chemicals were added to prevent the concrete from setting too soon.

Specialities: Careful planning and manual labour with millimetre accuracy were required to assemble and suspend the shuttering. The concrete of the superstructure was poured simultaneously at five places and then treated. 25 workers, three concrete pumps and two hydraulic jacks as well as five specially pre-fabricated electric screed rails were deployed over the course of 8 hours.

Map

Specific figures

Organisation

Project implementation as solo venture

Construction period

2009 - 2010

Construction costs

CHF 1.1 million