By Lynda Myer
The process of trialing the use of crushed glass in structural concrete at the new State Library Station is undergoing by Melbourne’s Metro Tunnel Project with the University of Melbourne and industry partners.
Decreasing reliance on virgin sand and diverting waste glass from landfill, this trial has demonstrated that recycled crushed glass can be used instead of virgin sand in concrete mix up to 25%.
Construction of temporary suspended concrete slabs was done using the crushed glass concrete mix, producing a concrete mix of equal strength and quality to traditional concrete.
While it has previously been limited to footpaths and local roads, currently it is the first time that a recycled glass concrete mix has been used in a structural application on a major infrastructure project.
Including Lendlease Engineering, John Holland Bouygues Construction and Capella Capital, Cross Yarra Partnership, states it is considering further trials at the University of Melbourne – with the potential to increase virgin sand replacement from 25% to 80% crushed glass, whereas this consortium is completing the tunnels and stations contract.
According to CYP sustainability lead Mick Lo Monaco: “The consortium hoped that by providing a field trial site for the research it could pave the way for full-scale commercialization of recycled glass in structural concrete.”
The research is part of the project’s sustainability commitment.
Also usage of recycled industrial by-products instead of cement, caused over than 50% reduce in project’s cement use.
As the first step towards a metro-style rail network for Melbourne, the Metro Tunnel involves twin 9km tunnels from the west of the city to the south-east and five underground stations, while the four TBMs completed tunneling in May 2021.
