Plastic roads: the future of highways?

Plastic roads: the future of highways?

Plastic roads are one of the greatest innovations of the past decade in the transport sector. They have a huge potential to solve two major problems in the UK. On the one hand, it helps to tackle the plastic waste problem. On the other, it also helps to improve the pavements of our roads by eliminating potholes. This article will explain everything you need to know about plastic roads.

The two main types of plastic roads

Plastic roads may sound like a new concept for many. The truth, however, is that the first patent for a plastic-bitumen road was created back in 2006, whilst the concept was developed further back in 2001. The engineering sector is constantly trying to reinvent itself, seeking new innovative materials to provide better solutions to the world’s problems. When it comes to roads and highways, it seemed that innovation had been forgotten for a while. Luckily, a few visionaries challenged the status quo of traditional pavements and came up with new ideas to change the future of roads.

There are two main types of plastic roads. The first one consists of an asphalt mix with plastic waste incorporated into the mixture. The resulting road is a ‘plastic road.’ The structure and construction technique for this first type is very similar to traditional pavements. The second type, developed by one company, is known as ‘PlasticRoad.’ In this case, the PlasticRoad consists of a modular, hollow road made entirely with plastics. Let us explore each of these types in more detail.

Adding plastics to the asphalt mixture of roads

Reducing the environmental footprint of highways is a major challenge for the UK, especially to meet its commitment to carbon neutrality by 2050. To help tackle this challenge, Scotland-based company MacRebur is leading the way of plastic roads. Their mission is ‘to help solve two world problems; to help solve the waste plastic epidemic, and to enhance the asphalt used to make our road surfaces around the world.

Their patented plastic road mix replaces part of the bitumen – obtained from fossil fuels – by household plastic waste. More specifically, they use between three and ten kilogrammes of plastic in every tonne of road mixture. The good thing about MacRebur’s plastic road mixture is that it uses non-recyclable plastics from household waste. This means that their asphalt mixture reduces the amount of plastic being incinerated or sent to landfill. According to MacRebur, each kilometre of road built with their product saves over 740,000 single-use plastic bags from going to landfill. It could also offset nearly 8,000 kilogrammes of CO2. 1 tonne of MacRebur mix contains the equivalent of 80,000 plastic bottles.

Successful trials lead to further investment in plastic roads

MacRebur’s plastic roads have been widely tested throughout the UK. Cumbria carried out the first trials back in 2016. After the successful initial trials, Cumbria County Council decided to invest £200,000 in resurfacing the A7.  The scheme used a total of 500,000 bottles and 800,000 plastic bags and saved around 5 tonnes of carbon emissions. Cumbria County Council senior asset and network manager Andy Brown explained:

‘We are adding a material that reflects about 6% of the bitumen binder in the asphalt mix. That percentage, as an overall, is only about 0.3% of the asphalt. From a highway roads point of view that does not make a lot of difference, but when you put in the volumes that we are referring to and [consider] how much of the waste plastic is used then that becomes a much more interesting economic model.’

In light of the successful outcomes, the government gave Cumbria County Council £1.6 million to gather further evidence about the effectiveness of plastic roads and to produce a guide for other local authorities wanting to introduce them. The government funding will enable Cumbria council to work with MacRebur and the Universities of Central Lancashire, California and Sunshine Coast Australia.

PlasticRoad – the modular road made of 100% recycled plastic

The other innovative solution is PlasticRoad – a modular and hollow 100% recycled plastic road. The concept was initially announced in 2015, developed by Dutch construction company Volker Wessels. The process involves forming recycled plastic waste into lightweight modules with hollow interiors for cables and plastic pipes which also allow excess water to drain. The prefabricated units would be easy to transport, assemble and maintain, and that the lighter weight means the ground would be less prone to subsidence. The company also claims that the PlasticRoad is two to three times more durable than traditional roads.

Back in 2018, the world’s first plastic cycle path made of recycled bottles opened in the Netherlands. Sensors within the PlasticRoad monitor the road’s performance. They measure temperature, the number of bikes that pass over it and its ability to cope with the traffic. This is very in line with the concept of Digital Twins, which connects real-world assets with digital assets through the use of sensors.

Contributing to a circular economy

When the PlasticRoad reaches the end of its life, it can then be crushed and re-used to make another PlasticRoad. This way, the company ensures that their product contributes to a circular economy. PlasticRoad’s manufacturer expects commercialisation on an industrial scale from the beginning of 2021. The following video provides a good explanation of their concept:

There are still challenges to be overcome. For example, the substitution of PlasticRoad modules involves disconnecting underground utilities. Also, standard plastic roads still have issues associated with the melting process of different types of plastics. However, it seems that plastic roads are finding their way to a bright future in the transportation sector.

What do you think about plastic roads? Let us know your thoughts in the comments below!

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