A revolutionary new method for replacing steel mesh used in concrete reinforcement with recycled plastic has seen Queensland engineering firm Fibercon, recycle over 50 tonnes of plastic waste.
Developed in conjunction with researchers from Queensland’s James Cook University the technology uses recycled polypropylene plastic for reinforcing concrete instead of the traditional steel, resulting in reduced CO2 emissions, water usage and fossil fuels.
Since its first use in 2017 the technology incorporated into Fibercon’s Emesh product has been used by councils predominantly in footpaths, but also has applications from pavement concrete to channel drains, embankment erosion control, precast sewer and stormwater pits.
According to a report prepared for the Department of Environment & Energy in 2016 Australia averages 107kg of plastic waste per person each year. “So we have effectively recycled the plastic waste for 467 Australians,” explained Fibercon CEO Mark Combe.
Steel reinforcement in concrete – or rebar – was first introduced in the mid 18th century as a means of improving the tensile strength of concrete, and is now the most commonly used form of concrete.
With concrete use at approx. 1m3 per person, Australia uses 25 million m3 of concrete per year. Conservatively, 5% is footpath and light pavements - equating to 1.25million m3.
“If we replaced all the steel mesh in these pavements with Emesh, we would reduce our CO2 by 125,000 tonnes annually, and re-use 5,000 tonnes of waste plastic”, Combe said. “It’s an exciting goal for us.”
Worldwide around 1.6 billion tonnes of steel is produced per year, making steelmaking one of the world’s leading industrial sources of greenhouse gases. It is also heavily dependent on the use of fossil fuels and water.
The process makes steel from iron ore by heating it with carbon – predominantly coal; carbon dioxide is produced as a by-product. Production of a ton of steel generates almost two tonnes of CO2 emissions, accounting for as much as five per cent of the world’s total greenhouse-gas emissions.
By using the recycled plastic technology Fibercon has also seen a reduction to date of 1,000 tons of CO2, 200 tonnes of fossil fuels reduction, and a 18,000 m3 of water reduction.
“According to the United States Environmental Protection Agency calculations, the reductions we have achieved in CO2 emissions, are the equivalent of taking 214 passenger cars off the road for 1 year,” Combe said.
“Plastic fibres in concrete have been around for 20 years – what is new about our product is that it is 100% recycled. The intention is to do something to give back, to close the cycle of useless waste."