Sydney road drives world-first green concrete trial
27 June 2019
Concrete made using industrial
waste
from coal-fired power stations and steel manufacturing is being used in
a world-first green
roads trial in
Sydney.
The
City of Sydney is putting the environmentally friendly building
product to the test on a busy inner-city street, replacing a 30 metre
section of roadway on Wyndham Street in Alexandria.
To test the green concretes durability, the City has laid a 15 metres
traditional concrete and 15 metres of
Geopolymer concrete, a sustainable
blend of concrete and recycled materials.
As a major road leading to Sydney Airport, the high traffic volume
provides the perfect conditions for the trial.
Nine sensors have been positioned under the concrete to monitor and
compare how the Geopolymer concrete performs.
UNSW
Sydney researchers and the CRC for Low Carbon Living (CRCLCL) will
then use results from the trial to create the first set of industry
guidelines for Geopolymer concrete.
Lord Mayor Clover Moore said the City was committed to finding new ways
to lower carbon
emissions.
“I’m proud that the City of Sydney was Australia’s first carbon-neutral
local government and that we’re continuing to take significant steps to
reduce our carbon footprint,” the Lord Mayor said.
“Projects like this Geopolymer trial can result in new products that
make a real difference in slashing carbon emissions.
“Local governments are responsible for maintaining local roads, so if we
can purchase more environmentally sustainable materials, we can fight
climate change and provide quality infrastructure for our community.
“With 70 percent of the concrete produced today going into pavements and
footpaths, there’s great potential to further lower emissions from our
operations.
“We’re continually working with concrete suppliers to reduce the amount
of pollution and greenhouse gases emitted during the production of
concrete for our local
roads, and we already use sustainable green concrete for all our
footway renewal works – which adds up to 25,000m2 per year.”
Made from fly ash and blast furnace slag, Geopolymer generates just 300
kilograms of CO2 per tonne of cement, compared to the 900 kilograms from
traditional cement production – saving the equivalent of the electricity
used by an average household every two weeks.
Research has been undertaken since the 90’s into geopolymer, but it’s
only now that it is being explored as a product that is not only better
for the
environment, but also commercially viable.
The low CO2 concrete has the potential to put the 400 million cubic
tonnes of globally documented waste from the coal and steel industries
to good use. While a small amount is currently used in construction,
much of it is currently stored on site.
UNSW Sydney researchers will monitor the road performance for up to five
years. Professor Stephen Foster, Head of School of Civil and
Environmental Engineering, is the CRCLCL project lead and describes the
trial as “a huge step forward”.
“This trial will help drive step change in the industry. Many concrete
companies are already doing a lot to change, but this trial really gives
it another push,” Professor Foster said.
“Research into Geopolymer has been undertaken since the 90s, but it’s
only now that it’s starting to be commercialised.
“While we’ll monitor the road performance for up to five years, a lot of
the data collected in the first three to 12 months of this world-first
trial will be used to confirm our models and strengthen our predictions.
“Concrete contributes seven per cent of all greenhouse gas emissions and
in 2018 the world produced about 4.1 billion tonnes of cement, which
contributed about 3.5 billion tonnes of CO2.
“Alternative, low CO2 concrete materials offer potential benefits in
reducing the greenhouse gas emissions associated with conventional
concrete.
“This trial is important because we need demonstration projects to
accurately assess the performance of Geopolymer over time so that there
can be broader uptake.”
Industry partner Craig Heidrich, executive director, Australian (Iron
and Steel) Association and Ash Development Association, says the
benefits of the trial will be far-reaching.
“Our collaboration with organisations such as the City of Sydney and the
publication of the research findings will further de-mystify and promote
the use of Geopolymer concrete in construction.
“Geopolymer concrete has great engineering properties. It is a durable,
high performance product that has a low carbon footprint when used in
construction,” Mr Heidrich said.
“It's a fundamental tenet in business that you need to be constantly
innovating and investing into new technologies. This trial will provide
real examples of Geopolymer concrete use that we can all use.”
According to Dr Tommy Wiedmann, Associate Professor of Sustainability
Research at UNSW, if all concrete was produced in one year was
Geopolymer instead of traditional concrete, this would save 12,000
kiloton CO2 per year.
A timelapse video is available for use: cityofsydney.wistia.com/medias/c7xf397dx7
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Source: NSW Government - www.cityofsydney.nsw.gov.au
Contact: N/A
External Links: cityofsydney.wistia.com/medias/c7xf397dx7
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