Research into the different types of concrete bridge girders used around the world will inform best practice in New Zealand.
Professional Services firm WSP has carried out a global review of superstructure beam types. The researchers involved believe that their findings could offer opportunities to reduce costs and improve sustainability, with significant implications for New Zealand’s approach to standardised bridge design.
The study compared girder types utilised in five regions, using a common benchmark – a 30m long, 15m wide single-span precast, prestressed concrete highway bridge.
Researchers note that some countries favour deeper, heavier beam sections, while others achieve greater efficiency with slimmer profiles.
New Zealand commonly uses hollow core and Super T beams, while the UK uses Y-beams and U-beams – but both these regions are turning to bulb-tee/NU girder like the sections favoured by the US, but optimised for Eurocode loading and durability. In Australia, it’s common to use Super T girders, while Canada prefers I and NU girders.
Understanding the regional variations will inform New Zealand’s designers as they balance strength, sustainability and economy.
