Most of us are aware of the problem we face when it comes to plastic waste. From landfill to oceans, plastic is a disease that is consuming our planet1. If we can put our discarded plastic to use elsewhere rather than it making its way into landfill or the environment we can take steps to reduce our environmental impact. Thus, the use of plastic waste in road construction looks like an innovation set for growth.
Across the globe, road networks connect people. They are the economic bloodline for businesses, travel and connect our cities. We’d struggle to live without roads9. However, whether we are constructing roads or maintaining roads, a lot of raw materials go into these near-endless strips of connectivity.
Typically, this can include products such as hot bitumen, which derives from fossil fuels. These materials come from polluting sources. Further, we also eat into many other resources such as aggregates when we lay new roads or maintain existing ones5.
As a result, we should be looking at new ways in which to make use of plastic waste. Whilst most of us are more aware and active reducing, reusing and recycling, loads of plastic still gets discarded. Whereas we might say no to plastic bottles, they still abound. Thus, using plastic waste in road construction could well prove part of the solution6.
For decades, plastic has been used in a range of applications. It is durable, versatile and flexible and these key characteristics make plastic waste in road construction suitable for the purpose.
So many different types of plastic are thrown into landfill or taken to recycling centres each year. In fact, packaging generates 141 million tonnes of waste annually and this contributes to 50% of the plastic waste problem globally.
Meanwhile, the truth is traditional asphalt, although it has been fit for purpose for decades, it does not last. Roads made from asphalt can suffer from the freeze-thaw process and heavy use can result in potholes. On-going maintenance costs money, it uses further resources and it causes disruption.
Traditionally, we have used hot aggregates and other products to construct roads. Yet with landfills brimming with materials like plastic, that could be reused, innovative solutions start to look like they could replace the need for these raw materials.
With so many roads that require construction or need maintaining, it makes sense to look at alternatives as we seek new ways to reduce our environmental harm.
As we search for new ways to use plastic and recycle it, using it in roads provides literally miles and miles of possibilities. If we marry the sheer volume of plastic waste we generate with the requirement for roads and their upkeep we can see a future that helps remove waste from the system7.
This is where plastic waste can play a growing role. Creating new applications towards the end of plastics lifecycle just makes sense. Today we’re turning plastic into clothes, banning plastic straws and we’ve even invented biodegradable plastic bags. When we have so much plastic waste that we can use and with the technology out there, why not make a change?
Fortunately, using plastic to create an eco-friendly road is completely possible3 and it seems as though it can be used in a number of ways.
Much like any of a number of other areas for progress, roads can be improved. They need a longer lifespan, reduced construction times and they need to become more sustainable.
What’s more, in modern cities, roads need to help reduce noise while the financial aspect of road construction and maintenance also play a part. Fortunately, plastic waste can help to deal with most of, if not all of these problems.
We are making progress and new initiatives and projects are now in place to help use plastic waste in road construction
We now have the ability to reuse plastic bottles and plastic bags and use them to make asphalt4, but how?
In some cases, plastic is being recycled into asphalt mixture. Shredded plastic is melted further to replace certain materials in the road construction process. In the UK, some councils are testing plastic roads. These projects involve using plastic pellets and plastic coated aggregate. As these are melted, the plastic is added to the mix and it acts as a binding ingredient2.
Manufacturers claim that this will make roads more durable and longer-lasting. What’s more, it is also kinder to the environment which is something that we are all striving for. As a result, the plastic will make up around 0.5% of the mixture. The roads are stronger, will not suffer from the same wear and tear while it also prevents plastic waste from going to landfill.
In Holland, they have taken things a lot further. Instead of using plastic as a small part of the process, they have created roads that are made completely of plastic.
Known as smart cities, Zwolle in the west of Amsterdam became the first area to trial plastic roads. The trial took place in 2016 and was such a success that it became the first official city to have plastic roads.
This futuristic plastic road contains sensors that can help further development. They also contain space for services such as cables and pipes. What’s more, they also contain a stormwater management system.
The installation is quick and simple as the road consists of sections. With prefabricated sections, if a section needs replacing, it is a case of removing the section and replacing it quickly and efficiently.
This project was such a success that the installation of plastic roads also took place in Giethoorn, another city in Holland. The aim is to continue to roll out these types of plastic roads and even use plastic for pedestrians as it improves the quality of flexible pavements.
It seems as though plastic roads come with a huge array of benefits.
The University of California has recently had a plastic road installed. Using plastic waste and created by MacReber, a UK based company, it is the first plastic road in the US. The company has experience in plastic roads as it has already installed roads in the UK and Australia.
The roads use plastic-suffused asphalt and that helps to reduce the amount of petroleum used. It is also more cost-efficient than traditional asphalt. Again, this is another example of how we can create sustainable roads.
First and foremost, using plastic waste is a feasible solution to the problem we face. Along with this, as the bitumen used in the mix is being partly replaced, it means that we are using fewer fossil fuels. Again, this is another significant positive in the fight to save our planet.
It is an environmentally friendly way of making use of waste, preventing waste from going to landfill. However, where it can really stand out is the way in which plastic roads, particularly those made completely from plastic, can completely change our ways.
If we can prefabricate roads, it means that we can construct roads more efficiently. Whether we are building new roads or repairing, it will require less manpower and time. Plastic roads become reusable as it is simple to remove them, recycle them and repurpose them. The process is far less intrusive than that of traditional roads and that can help the environment in many ways8, in particular, helping to reduce greenhouse gases.
Traditionally, we lay pipes and cables under roads. However, plastic roads can help to make this process a lot easier. The hollow space in the design can assist in the laying of cables and pipework. Along with this, they can store water and that can also help to reduce flooding, surface water and traffic safety.
The technology is completely scalable. It encourages further innovation and new ways to incorporate technology into our roads such as solar power.
Plastic is a material that can prove to be a problem for the health of humans and animals. It can leach, we can consume it if it breaks down and that can result in a wide range of health problems . Despite this, we are making advances.
Companies such as MacReber ensure that all of their plastics fully homogenise into the mix. What this means is that there are no microplastics in the final material. Only a polymer-modified bitumen. As there are no microplastics, it means that no leaching can take place, making plastic roads safe for the environment and our health.
If we need to seek a solution to plastic waste then road construction using plastic look set to play a significant role. MacRebur claims that it uses 71,432 plastic bottles or 435,592 plastic bags in every 10 tons of asphalt it makes. As such, the potential is clear.
With a huge array of benefits including environmental and cost benefits, there is no doubt that we’re likely to be driving on more roads made from our discarded plastic waste.
|Barnes David K. A., Galgani Francois, Thompson Richard C. and Barlaz Morton. Accumulation and fragmentation of plastic debris in global environments. 364. Phil. Trans. R. Soc. B http://doi.org/10.1098/rstb.2008.0205|
|Yetkin Yildirim, Polymer modified asphalt binders, Construction and Building Materials, Volume 21, Issue 1, 2007, Pages 66-72, ISSN 0950-0618, https://doi.org/10.1016/j.conbuildmat.2005.07.007|
|Potential Reuse of Plastic Waste in Road Construction: A Review. Amol S. Bale. International Journal of Advanced Engineering Technology|
|Moghaddam, T.B. and Karim, M.R. and Soltani, M. (2013) Utilization of waste plastic bottles in asphalt mixture. Journal of Engineering Science and Technology, 8 (3). pp. 264-271. ISSN 18234690|
|ROAD CONSTRUCTION MATERIALS AS A SOURCE OF POLLUTANTS. Luleaa Hoegskola. Avdelningen foer Transportteknik. Luleaa, Sweden|
|Utilization of Plastic Waste in Construction of Roads. G. Paul Pandi, S. Raghav, D. Tamil Selvam, K. Udhaya kumar, Department of Civil. Sethu Institute of Technology, Virudhunagar, India|
|Study on Use of Plastic Waste in Road Construction. Mercy Joseph Poweth, Solly George, Jessy Paul. International Journal of Innovative Research in Science, Engineering and Technology|
|Pettee, Stephanie. (2018). Recycling Plastic – a Toxic Impact to our Future. 10.13140/RG.2.2.35181.44000.|
|Whitelegg, John. (2019). ROADS, JOBS AND THE ECONOMY.|