The Omega Bridge on the south coast of NSW (Gerringong) officially opened on the 13th of February 2015. The Bridge is over 340 metres long and is the lynchpin for the $329 million Princess Highway upgrade between Gerringong and Gerroa. Interestingly, the Bridge was constructed using the same method as the Sea Cliff Bridge construction in 2005.
The method used is known as incremental launching, in which segments are pushed and added to the bridge so to connect with the previous segment. This method reduced the amount of cranes needed to assemble the bridge while at the same time, decreasing the environmental impact on the nearby Werri Lagoon. Due to the massive weight of the piers which support the bridge, a concrete mix was developed which included 30% fly ash.
The fly ash mix increased workability, working time and ensured that the core temperatures and temperature gradients of the concrete were kept at a sufficient level. To read more about the project, visit: http://www.abc.net.au/local/stories/2014/09/12/4086323.htm