Kris Croft: Bottling innovation

Halting the exports of recycling waste is having a mountainous impact, with growing piles of bottles looking for a home across Australia. With this problem, though, comes an opportunity.

“People have been frantically trying to solve this problem, and one of the obvious solutions is to recycle glass back to what it was originally – sand,” says Ben Hayward, GM Infrastructure Services, Eastern Region.

Sand typically makes up between 10% and 15% of asphalt by mass. It is often transported large distances to urban sites – often more than 100 kilometres – adding a considerable carbon emission burden on the environment. Fulton Hogan has been working with Transport for New South Wales (TfNSW) to modify asphalt mixes to include crushed glass as a sand substitute in asphalt, allowing the raw material to be sourced much closer to where it’s needed.

In recognition of Fulton Hogan’s leadership in this space, the company has been awarded a A$250,000 grant from the NSW Government to upgrade its Eastern Creek asphalt plant, and a further A$236,000 grant to use recycled glass in asphalt on the Albion Park Rail bypass project.

This project is a NSW Environmental Protection Authority, Waste Less Recycle More Initiative funded from the waste levy

Albion Park Rail bypass is a marquee site for the use of crushed glass in New South Wales. On the project, being delivered by Fulton Hogan Construction on behalf of TfNSW, crushed glass will make up to 10% of the base course, by mass. This means between two thirds and three quarters of the sand used in the structural asphalt layers on the project will have originated as recycled glass.

Fulton Hogan has undertaken detailed laboratory testing of particle sizes and grading envelopes, and has optimised the asphalts mix properties for the recycled glass. This blend ensures high performance results are achieved under various test methods.

An additional feeder and conveyor has been added to the Fulton Hogan Eastern Creek asphalt plant, enabling glass to be blended along with recycled asphalt (RAP), thus maximising the amount of recycled product being incorporated into the end product. “We didn’t want the addition of crushed glass to be at the expense of our use of RAP, and we are happily able to use maximum levels of both in the mix whilst maintaining the high performance levels required under our specifications,” says Ben.