Around the world, there has been a shift toward an environmentally conscious approach to road construction – and one material is beginning to crop up as a favourite.
As a globally ubiquitous material, waste plastic is readily available and cheap. It also poses a major threat to the environment and is clogging up landfill sites – so any process that can transform it into something useful is a win-win.
Here are just some of the current projects utilising plastic waste:
Recycled plastic in India
In India, plastic is a big problem. The country’s Central Pollution Control Board says more than 15,000 tonnes of plastic waste are generated daily. For Dr R Vasudevan however, the ample supply of plastic presents an opportunity.
Vasudevan, a chemistry professor and dean at the Thiagarajar College of Engineering in Madurai, has gained a reputation as “the plastic man of India” thanks to his patented technique for combining waste plastic with asphalt. Vasudeven
developed his method by sprinkling shredded plastic waste over hot gravel and coating the stones in a thin film of plastic. He then added the plastic-coated stones to asphalt (plastic and tar bond well together because both are petroleum products).
To date, more than 5000km of plastic roads have been laid in at least 11 states. The Central Pollution Control Board and the Indian Roads Congress have endorsed the method.
According to Business Week Magazine,
Almitra Patel, one of India’s leading experts on garbage, considers Vasudevan’s technology a “win-win-win," because it consumes an unwanted and mostly nonrecyclable resource; it results in stronger roads; and it replaces as much as 15% of more expensive bitumen in the mix used to lay roads, potentially lowering the cost of road infrastructure.The Guardian reports
that Jambulingam Street in Chennai, built in 2002 and one of the first roads to incorporate Vasudevan's recycled plastic, has withstood heavy traffic, a flood, monsoons and recurring heat waves without showing the usual signs of wear and tear.
The Times of India
reports that Vasudevan has been inundated with offers, but has chosen to share his expertise free-of-cost with the Indian government.
“If the existing roads are scrapped and relaid with plastic, they will not require maintenance for years and endure three times the load that is taken by the ordinary ones," Vasudevan says.
"When the floods washed away almost every road in Chennai last year, only the plastic ones survived. Similarly, only the stretches of plastic roads remained when the water gushed through Mumbai streets in 2005.”
It’s an idea echoed by UK startup MacRebur
. The company's promise to create reduced-maintenance roads while consuming waste plastic caught Richard Branson's eye and saw it win the 2016 Virgin Media Business Voom competition.
MacRebur holds the UK and European patent on the method and recipe of mixing waste plastic pellets with bitumen and their so-called 'magic formula', to produce a new asphalt road material.
The company claims that, compared to current British standard asphalt, their product produces a 60% stronger road.
It is within British and European standards and is a patent pending.
Tests have also shown that the material:
- Reduces potholes
- Reduces rutting
- Increases the lifespan of the road
One of the more outlandish ideas to surface recently is that of PlasticRoad.
The PlasticRoad design appears to be the closest thing public works professionals can get to building roads with Lego. Invented by Netherlands-based duo Anne Koudstaal and Simon Jorritsma, the PlasticRoad design uses recycled plastic waste to form prefabricated, lightweight modules with hollow interiors, that the designers say can be fitted with cables and plastic pipes and allow excess water to drain.
The project’s website claims the design will have a lifetime three times that of a regular road. The pre-fabricated units will apparently be easy to transport, assemble and maintain, and the lighter weight means the ground will be less prone to subsidence.
The website states: “The objective is to create a road with a smaller ecological footprint than traditional road systems. When the elements reach their end of life expectancy, they can be recycled again to build a new PlasticRoad.”
Koudstaal told Paste Magazine that PlasticRoad is also “future-proofed” – if someone has a bright idea that requires the space beneath the road, they can remove an element of the road, make an installation, and reinsert the module – with minimal road work and traffic delays.
PlasticRoad also uses a lighter colour palette to deliberately reduce heat absorption. The modules can withstand temperatures ranging from -40 to 80 degrees Celsius, a far more flexible range than that of asphalt.
The plan is for material to be sourced locally from recycling centres, reducing transport by 80%.
The PlasticRoad concept was first floated in 2015 by Dutch construction company VolkerWessels. In 2016, companies Wavin and Total also came on board.
On the PlasticRoad website, Koudstaal and Jorritsma say: "Together with Wavin and Total, we now have a vast pool of knowledge, experience and resources, and can take concrete steps in the development of PlasticRoad. We expect to have a first prototype completed by year-end 2017.”
The PlasticRoad website states:
“Several municipalities, provinces and regional water authorities have already shown interest and offered a pilot location to test the PlasticRoad.”
However, it remains to be seen whether the PlasticRoad is just a pipe dream.
In the website’s Q&A section, there’s a whole lot of “wait and see”-type answers.
Under the heading “How feasible is it to actually produce plastic roads”, the answer given is:
“KWS Infra believes in the feasibility of the idea and we are making substantial investments in further research into the PlasticRoad. The research will have to reveal whether the idea is feasible in practice.”
Of course, there is plenty of innovation taking place closer to home. intouch
has previously reported on the use of recycled printer cartridges
in road construction, and you can read about the business case for using recycled materials in roads here.