• Products
  • Projects
  • Stories

Sydney, NSW launches world’s first geopolymer concrete test

The trial aims to define best practices for using concrete alternatives made from industrial byproducts.

Road & Traffic ManagementPublic WorksRecycling

Sydney, NSW


gallery media 1

World-first green concrete trial | Infrastructure Magazine

The City of Sydney is trialling the world’s first ‘green’ road on a major high-volume traffic road leading to Sydney Airport.

Infrastructure Magazine

UNSW Sydney researchers help drive world-first green concrete trial | UNSW Newsroom

Drivers on the way to Sydney Airport will stress test the new geopolymer concrete, which is made from industrial waste while emitting less greenhouse gas.

UNSW Newsroom

Sydney drives world-first green roads trial | City of Sydney - News

The City of Sydney puts environmentally friendly concrete to the test.


  • Sydney is testing geopolymer concrete made of coal and steel waste on a busy stretch of road.

  • Concrete production accounts for 7% of the world’s greenhouse gas emissions, but geopolymer concrete production creates significantly lower emissions than standard concrete.

  • Sensors in the road will monitor and compare the different concretes, to validate the green alternative’s viability for widespread use.

  • The test will run for five years and should result in a set of guidelines for geopolymer concrete use.


In cities, concrete is everywhere: roads, parking lots, buildings, footways. But concrete comes at a big environmental cost, as production causes heavy emissions of carbon dioxide.
Alternate forms of the material, made from recycled industrial waste, have been on the radar for decades, but were never widely considered for commercial use. Until now.
In 2019, the city of Sydney embarked on the world’s first test to learn how geopolymer concrete performs as a greener alternative for paving roads. By monitoring the trial via sensors over the next five years, the city hopes to find not only a solution for its own sustainability efforts, but also a set of best practices that can be shared for widespread adoption.

Concrete’s environmental problems

Concrete contributes to about 7 percent of the world’s greenhouse gas emissions. In 2018, 4.1 billion tonnes of cement were produced, emitting about 3.5 billion tonnes of carbon dioxide.
The majority — about 70 percent — of this concrete is used in roads and footways. What if there was a more environmentally friendly solution? What if cities could use a greener material to pave surfaces and build construction?
Sydney’s Lord Mayor Clover Moore understands the role cities must play in the effort to find a better approach:
In theory, it’s a huge opportunity. But any materials used also have to be strong, safe, and easy enough to produce for widespread use. So Sydney set out to test its viability.

What is geopolymer concrete?

Sydney is experimenting with geopolymer concrete, a blend of fly ash and blast furnace slag — in other words, industrial waste from coal power stations and steel plants.
In addition to recycling byproducts, producing the geopolymer material creates only 300 kg of carbon dioxide per tonne of concrete. Standard concrete, on the other hand, produces 900 kg of carbon dioxide per tonne. This means that geopolymer offers an energy savings that’s about the same as the amount of electricity an average family home uses in two weeks.
It’s also tough stuff. According to one of the trial’s partners, Craig Heidrich, executive director, Australian (Iron and Steel) Association and Ash Development Association:
But is it as durable enough to be used commercially? The city of Sydney partnered with the University of New South Wales, the CRC for Low Carbon Living, and other organisations like Heidrich’s to find out.

Testing the geopolymer concrete

To test the concrete, the city selected Wyndham Street, a highly trafficked road in the suburb of Alexandria. The route leads to the airport, meaning the volume of cars should be a good stress test.
A 30-metre stretch of road (that already needed repair) was split into two sections: 15 metres were laid with standard concrete. The other 15 metres got the geopolymer concrete. A series of sensors was placed in the concrete to monitor its status and compare performance.
The test will be monitored for up to five years — though some early data should be available sooner, even after 12 months.
Ultimately, the city and researchers plan to turn the trial into a handbook that outlines best practices and details how to use sustainable concrete options in roads and construction.
It’s an effort that could have a huge global impact: By looking beyond local benefits and creating a shared resource for greener construction, Sydney’s geopolymer trial could help repurpose more than 400 million cubic tonnes of coal and steel waste worldwide, and help reduce carbon emissions. It’s a great example of how when local governments share their learnings, it can affect greater change beyond one community.

Sydney’s environmental mission

This isn’t Sydney’s first foray into sustainable construction. The NSW capital is a leader in Australia, becoming the first local council in the country to be certified as carbon neutral. The city has undertaken a number of green initiatives, from solar power to LED lighting to sensors and business partnerships.
According to Sydney’s Lord Mayor Clover Moore, the geopolymer concrete trial is another step toward a more sustainable future:


🚫 To join the discussion, sign up. It's free!


Lindsay Pica

Co-founder at Govlaunch



In Progress


Project plan

Related Stories

story cover image

a month ago

Colerain Township fights the opioid epidemic with compassion

The Ohio town has developed a human-centered approach to addiction support services that has grown so successful it’s now used in at least eight states.

story cover image

a month ago

Rochester, MI looks to the future to innovate now

The city puts a forward-thinking lens on its present-day programs in order to budget more effectively and drive change.

  • Help
  • Blog
  • Terms of Service
  • Privacy
  • Cookie Policy
  • Contact

© 2020 Govlaunch Inc.