One square metre of this materials can
withstand 8,000 tonnes and 1,600^oC.
Image: Curtin University of Technology

As Australia becomes hotter and drier, we will increasingly be threatened by ferocious bushfires. After 173 Victorians were killed on ‘Black Saturday’, it’s obvious that we need better ways to protect ourselves. Fireproof bunkers may not be far away thanks to the development of a new type of ultra strong concrete.

The geopolymer, developed by William Rickard and a team from Curtin University of Technology, can withstand temperatures of over 1600^oC for at least an hour - heat that would rip through regular walls.

Bomb proof
The super concrete can also defend us from less natural types of fire – its resilience makes it ideal bomb shelter material. In addition to scorching flames, the geopolymer can withstand almost three times more pressure than run-of-the-mill concrete. To put it into perspective, you could stack 8,000 tonnes (that’s about 5,000 Ford Falcons) on a square metre of this stuff and it still wouldn’t crack. There has also been a lot of research to suggest that geopolymers can provide protection from radiation, which will be handy if we ever face nuclear war.

Super concrete for everyone
The material may sound like something you’d find in a NASA budget, but it will actually be cheaper than regular cement because it’s made from fly ash, a waste product of coal-fired power plants. The ash, which is usually dumped into landfill or dams, is the reason the material is so tough. “We already knew that geopolymers were strong, but making them with fly ash gave them excellent fire resistance,” said Rickard.

Better for the planet
The environmental benefits of the material don’t stop at cleaning up power stations’ waste – the geopolymer is made using significantly less heat (1330^oC less to be precise) than traditional concrete, cutting greenhouse gas emissions by 80 per cent. “Five to eight per cent of the world’s emissions come from manufacturing cement, so not only can we reuse industrial waste, we can help to reduce the impact of global warming,” said Rickard.

Because the new geopolymer will be used primarily as a safety product, there is a lot of testing to be done, but Rickard is optimistic it will be available and saving lives within two years. The potential is huge – we have created resilient materials in the past, but the fact that this fireproof concrete is also sustainable and cheap makes it an ideal building block of the future.