New modular construction method for multi-span concrete bridges with reduced material consumption

A new construction method for post-tensioned bridges with a double-T cross-section was developed at the Institute of Structural Engineering (TU Wien). That method enables a swift production of the longitudinal girders and the deck slab. Precast deck slab elements stiffened by cross-beams are placed on top of the installed post-tensioned precast girders. The precast hollow box girders and the deck slab elements can be installed along the whole length of the bridge with cranes or a launch- ing gantry. The combination of precast hollow box bridge girders and precast deck slab elements allows for the fast production of post-tensioned concrete bridges with a double-T cross-section in the span range from 30 m to 60 m. This method will make the erection of one span per week possi- ble, thus achieving the same construction speed as segmental bridge construction. Compared with segmental box girder bridges, the new construction method permits a reduction of construction materials and avoids transverse joints that extend over the entire height of the finished cross-sec- tion.