Post-tensioning Perfectionist

Thanks to DEXTRA, the post-tensioning system has been perfectly adapted to the needs of the West Gate Tunnel in Australia.

The West Gate Tunnel, is a 4-km toll road in Melbourne, Australia, to link the West Gate Freeway at Yarraville with the Port of Melbourne and CityLink at Docklands via twin tunnels beneath Yarraville, as well as a bridge and elevated road section.

The bridge includes 300 piles of variable height. The piles have been precast in multiple segments, close to the site. Vertical post-tensioning bars assemble together all the segments of each pile. 

This construction method of piles is more and more common but requires a good preparation, both in terms of method statement and products definition. Each detail is important for the success of the installation. 

With a close cooperation between DEXTRA, Freyssinet back-office (Technical Department and Freyssinet products company) and the job site staff (Freyssinet Major Project and Freyssinet Australia), the post-tensioning system has been perfectly adapted to the needs of the project. The choice of the diameters and the steel grade of the bars, the design of the anchorages have been validated through qualification tests according to Australian Standards, demonstrating the performance of the system.

DEXTRA was in charge of the fabrication of more than 1,000 tonne of bars and 7,500 anchorages of Freyssibar+ D55 and D72, coordinated by Freyssinet Products Company and installed by Freyssinet on site, from 2019 to 2021. This success is mainly due to the synergies between DEXTRA, specialist of materials and production and Freyssinet historical major company for post-tensioning systems development and installation. It also shows the nice potential of this type of post-tensioning bar system.