A carbon-based technology that is being developed to add strength to concrete without much extra weight was recognised at the Civil Contractors Federation’s Environmental Choice Award last week.
Announced at the civil contracting industry’s 2014 Earth Awards, the technology by Perth-based Eden Energy triumphed over a field of six other finalists with its use of carbon nanotubes (CNT) to create greener and superior performance concrete.
According to Eden, CNT have a flexural strength 200-300 times stronger than steel. CNT-enriched concrete is expected to reduce the quantity of concrete required for structures, which in turn would lower the environmental impacts of concrete production.
Eden’s executive chairman Greg Solomon said the global cement market was worth around US$450 billion a year, and that the manufacture of such volumes of concrete is responsible for producing approximately five per cent of the world’s total annual greenhouse gas emissions.
“Our focus has been to use our emerging carbon nanotube productive capability to enhance the strength of concrete. Positive laboratory trials to date indicate that a potential reduction of cement requirements of between 15-30% could be possible,” explained Solomon.
“Not only is the result stronger, denser, tougher concrete but as less volume and potentially less steel reinforcing will be needed, this can flow on to reduced building costs, allowing greater design flexibility across the big concrete consumers in roads, bridges and high rise buildings.
“The denser cement matrix in the concrete is also anticipated to make the concrete both less permeable and less susceptible to breakdown due to absorption of saline water, particularly in coastal and marine situations.
“Additionally, our early work with our carbon nanotubes added to plastic and polymer shows similar potential gains in strength.”
The additive by Eden is set to go into commercial trials in both Australia and the United States over the next 12 months. The US field trials will initially target abrasion resistant applications such as the surfaces of roads and bridges.
Eden’s CNT are produced using its proprietary pyrolysis process and developed in conjunction with the University of Queensland. The process converts methane into the carbon nanotubes and hydrogen without directly producing CO2 as a by-product.
