Returned to a Natural State - Two Timber-Concrete-Composite Bridges in Wangen Im Allgäu

The 2024 state garden exhibition in Wangen im Allgäu saw the redevelopment of a former spinning mill and its industrialised and later neglected surroundings into an area for local recreation, and at the same time return them into a more natural state.The idea of re-claiming nature extended to the bridge design. First, untreated timber was chosen as primary material from a pool of materials investigated. Secondly, the bridges initially served construction traffic only to be “returned” to their permanent use as pedestrian- and cycling crossings. This established an immediate relationship to the evolving site, where nature was quick to reclaim the riverbanks and surroundings.For the structure, glued laminated beams act in composite with the concrete deck. At the abutments, the concrete wraps around the structural timber and continues monolithically into the foundations. Like an inlay to the concrete and away from the moist abutments, the timber is carefully protected from the elements. Fully integral, longevity is all but assured.Life-cycle assessments continuously performed throughout the design process and upon completion showed very favourable results when compared to similar span bridges.