Concrete and timber materials interact structurally on this new type of bridge that was manufactured in just eight weeks.
Measuring 25 metres-long and six metres-wide, the bridge’s primary structure comprises block-laminated timber beams with a stepped bottom edge. These beams were formed and glued over moulds in a factory offsite. Once delivered to the site, they became permanent formwork for the concrete deck which was cast on top in situ.
Designed to suit its rocky site spanning a river in southern Germany, the Baiersbronn Bridge exemplifies its sustainable ethos according to its designers, Moxon Architects, and “offers a scalable, low-maintenance solution with potential for wider application”.
Using shear connectors, the concrete works in compression along the top of the structure, with the timber working in tension underneath. This capitalizes on both materials’ inherent properties and strengths.
The depth of the beams increases at the bridge’s mid-point while elevating the relatively flat soffit above flood level. With the planar beams leaning outwards, the deck widens towards the centre.
Owing to timber being lightweight, the construction team was able to reuse the abutments from the previous crossing which had fallen into disrepair, according to Moxen Architects. This helped to contain costs while significantly reducing the project’s overall carbon footprint.
Image: Baiersbronn Bridge. Credit: Moxon Architects, Simon Kennedy.
About the author
Desi Corbett
Desi is the Editor of Concrete in Australia, at the helm since December 2013, and our weekly news writer since 2016. Focused on concrete and construction for more than 11 years, her expertise in this field forms part of a journalism career spanning three decades. To get in touch please email desi@corbettcomms.com