Steel- Concrete- Composite Bridges with Innovative Prefabricated Slab Elements: Fid-Bau Portal

Steel- Concrete- Composite Bridges with Innovative Prefabricated Slab Elements

Fuchs, Kerstin / Gaßner, Georg / Kollegger, Johann

Abstract The Institute of Structural Engineering of TU Wien is working on a new method for the construction of deck slabs for bridges, using partial-depth precast concrete elements with an in-situ concrete layer. Even though this construction method can be used for all types of bridges, the main focus for application is set on steel- concrete- composite bridges. For the main structure of a steel- concrete- composite bridge, a steel bridge girder will be erected by conventional construction methods in the first step. There are different methods for the construction of concrete bridge decks. They can either be made out of in-situ concrete, partial-depth precast elements or full-depth precast elements. In-situ slabs are either cast on fixed formwork or with the use of a formwork carriage. The new construction method is based on the advantages of both, formwork carriage and partial-depth precast elements. Building the slab with partial-depth precast elements, lattice girder elements are used. These elements will be delivered from the precast factory to the building site, where they are stored next to the abutment. The necessary reinforcement will be placed on the elements and an installation carriage will carry the elements to the installation site. The installation carriage has vertically adjustable steel bars for picking up the elements next to the abutment and carrying them to the installation site where the elements are situated in their final position. The additional reinforcement will be placed and a concrete layer will be applied. The essential advantage of this innovative construction method for the production of slabs for bridges is the reduction of construction time. While the fabrication of one slab section using a formwork carriage takes one week, the proposed method can double the speed of construction to two sections a week due to the high prefabrication level.