Councils reinforce concrete with recycled plastic

Australian councils are increasingly replacing the traditional steel mesh used to reinforce concrete in footpaths with recycled plastic, which would otherwise be sent to landfill or end up in our oceans.

Polypropylene (PP) is the second most widely used plastic in the world, with the lowest recycling rate — the American Chemistry Council estimates a rate below 1%. PP is also one of only three plastic types which floats — forming a major component of the ocean gyres and estimated 8 million tonnes of plastic entering the ocean each year.

There are only three things which can be done with plastic waste: recycling, energy recovery or landfill. Humans have created 8.3 billion tonnes of plastics since large-scale production began in the early 1950s — roughly half was produced in just the last 13 years, and an estimated 79% now resides in landfills or the natural environment.

Now, thanks to Queensland engineering firm Fibercon and researchers from James Cook University (JCU), councils are using recycled polypropylene (PP) plastic waste in the form of ‘Emesh’ to reinforce concrete pavements and other infrastructure. Townsville City Council was one of the first in Australia to use Emesh, made of 100% recycled PP, for 3500 m² of pathway on Magnetic Island.

“There are the environmental benefits that come with the use of recycled plastic, but also the fact that it is easy to transport the fibres, especially to Magnetic Island,” said Senior Project Manager Bob Hickey. “There are also no problems with corrosion in the saltwater environment. The result was an excellent product with no visible uncontrolled cracking.”

Fibercon CEO Mark Combe.

In addition to reduced CO₂ outputs and preservation of fossil fuels from steel manufacturing, the Emesh innovation also creates a market for recycled PP. To date, 65 tonnes of plastic waste has been recycled via Emesh, with the potential to recycle 5000 tonnes of plastic waste annually. One tonne of plastic is equivalent to around 20,000 litre bottles, or 120,000 plastic bags.

“Recycling is not just putting materials in a recycling bin at the kerbside: collection is only the start of the process,” said Fibercon CEO Mark Combe. “Markets must exist for recyclable materials and buyers must be found for products made with recyclable materials. With China drastically reducing its import of waste in 2017, finding new uses for recycled plastics is more important than ever.

“Simply by using our Emesh instead of steel reinforcement, councils can contribute significantly to cleaning up our plastic waste.”

Top image: Recycled fibres in concrete.