A revolutionary new method for replacing steel mesh used in concrete reinforcement with recycled plastic has seen Queensland engineering firm Fibercon recycle over 50 tons 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 carbon dioxide 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. Therefore, says Fibercon CEO Mark Combe, “We have effectively recycled the plastic waste for 467 Australians.”
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 approximately one cubic metre per person, Australia uses 25 million cubic metres of concrete per year. At a conservative estimate, 5% is footpath and light pavements – equating to 1.25 million cubic metres.
“If we replaced all the steel mesh in these pavements with Emesh, we would reduce our carbon dioxide by 125,000 tons annually, and reuse 5,000 tons of waste plastic,” says Combes. “It’s an exciting goal for us.”
Worldwide around 1.6 billion tons of steel is produced per year, and it is 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 tons of carbon dioxide emissions, making steelmaking one of the world’s leading industrial sources of greenhouse gases accounting for as much as 5% of total emissions.
By using the recycled plastic technology, Fibercon has also seen a reduction to date of 1,000 tons of carbon dioxide, 200 tons of fossil fuels reduction, and a 18,000 cubic metres of water reduction.
“According to the US Environmental Protection Agency calculations, the reductions we have achieved in carbon dioxide emissions, are the equivalent of taking 214 passenger cars off the road for one year,” says Combes. “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.”
With increasing recognition by governments at federal, state and local level of the need for sustainable building practices, Emesh is seen as a solution that can contribute to the ever-growing quest for carbon neutrality and reduced environmental impacts.