NEW DELHI: Scientists at University of New South Wales have turned the ash waste from coal-fired power stations into a global environmental solution which promises to slash emissions in construction sector by 20 per cent.
Researchers at UNSW have converted the fine particulate pollution generated in coal furnaces, known as fly ash, into a new range of high-strength, lightweight building materials.
The new lightweight fly-ash aggregate, known as Flashag, replaces quarried rocks such as blue metal and gravel which are usually mixed in with cement to make concrete. Flashag is the world’s first fly ash aggregate to drastically reduce the volume of cement needed to achieve high strength concrete structures.
UNSW’s commercial arm, NewSouth Innovations, is also negotiating to license the technology in Australia, India, Indonesia, the United States, and the Middle Eastern construction hubs of Dubai and Kuwait.
"The environmental consequences are enormous," says inventor, Dr Obada Kayali, a senior lecturer in Civil Engineering at UNSW@ADFA (the Australian Defence Force Academy).
It’s taken him a decade in the lab, but Dr Kayali says he’s finally turned a global industrial waste burden into a commercially-viable, environmental asset. The big savings in greenhouse gas emissions lie firstly in reducing the volume of cement needed to make high strength concrete.
Cement and concrete is one of the world's dirtiest industries, generating 10 to 12 per cent of all global emissions. Every tonne of cement manufactured, releases one tonne of carbon dioxide and for very person on earth one cubic metre of cement is produce every year.
"Cement is the culprit, in terms of greenhouse gas emissions. It is not sustainable any more to produce cement at current rates," says Dr Obada.
The 100 per cent fly ash bricks and pavers, known as Flash Bricks TM, are about 20 per cent lighter and stronger than their clay counterparts. This means further emissions savings because less steel and shallower concrete foundations are needed for the same sized structures.
China, where half the world’s construction is taking place, recently overtook the United States as the world’s single biggest polluter. The fly-ash products pilot plant opened in the Chinese city of Hebi earlier this year, in a special zone for sustainable industrial technologies and large scale industrial recycling.
Globally, coal-fired power generation has produced billions of tonnes of fly ash waste over the past century, with annual production now at about 800 million tonnes. Uncontrolled it is a serious source of air pollution. A small percentage of the world’s fly ash is already absorbed by the construction industry as an additive to cement, and is mixed-in with clay in bricks.
