Arup has developed an innovative timber bridge concept with partners Heijmans and Schaffitzel in response to a Circular Economy-inspired call for proposals by Dutch highways agency Rijkswaterstaat (RWS).
Embracing circular economy principles to focus on decarbonisation, our Bridges of Laminated Timber (BoLT) concept focuses on longevity, modularity and re-use.
While timber-concrete composites are being increasingly used on bridge superstructures, BoLT goes a step further by replacing the traditional concrete superstructure with laminated timber. This results in 75% of the superstructure’s total weight being a renewable material.
Designed for bridges with a span of up to 25 metres, BoLT uses high-quality Cross-Laminated Timber (CLT) for the bridge deck – appropriately protected with a waterproof membrane and asphalt deck - and block glued beams (Glued Laminated Timber, or GLT) for the main beams. The use of timber makes the entire structure CO2 neutral, yielding an Environmental Cost Indicator reduction (ECI or Milieu Kosten Indicator in Dutch) of 70% and reducing the use of primary abiotic materials by up to 90%.
BoLT can be used in new construction as well as for bridge deck renovations, where the existing substructure and foundations could be retained to support the lighter timber superstructure.