Plastic Roads: What They Are, How They’re Made, Pros & Cons, & More

In the guide below, we discuss various aspects of plastic roads and plastic road construction.

Specifically, we outline what plastic roads are, how they’re made, hat they are made of, potential pros & cons, whether they are sustainable & eco friendly, & other relevant information.

 

What Are Plastic Roads?

Plastic roads are roads that contain plastic, usually in the form of recycled/repurposed waste plastic

 

What Are Plastic Roads Made Of?

There’s multiple types of plastic road technology, and methods of plastic road construction.  Each one might use slightly different materials.

The two main types of plastic roads might be:

1. Plastic Composite Roads

Are made of composites of plastic, and are more common that 100% plastic roads at this point in time

One common type of plastic composite road mixes post consumer plastic with other materials or substances like bitumen and aggregate, to form a composite asphalt. The plastic can partially replace the aggregate, or it can replace some of the bitumen, depending on the composite road construction used

For example, MacRebur has a plastic road technology whereby ‘The polymers are made from 100% waste materials and are used in the making of both hot and warm mix asphalt’

However, other plastic road construction and plastic road technology can be used too

As one example, according to awe.gov.au, in 2021 it was announced that an Australian partnership was started to build the first plastic road with soft plastics, glass and toner

 

2. Roads Made Completely Of Plastic

In the Netherlands, there’s been at least one bicycle path made completely of recycled post consumer plastic/waste plastic

‘PlasticRoad’ has their own plastic road product, and indicates that it is made from ‘100% recycled polypropylene’

 

How Are Plastic Roads Made?

The way that plastic roads are made can differ depending on the type of road technology used.

However, in general, the way the two main types of plastic road might be made might be:

1. Plastic Composite Roads

The general process to make and lay these roads might be the collection, sorting, cleaning, shredding, and melting of post consumer plastic, and then mixing/blending it with bitumen and aggregates

This asphalt mixture can then be laid as regular asphalt concrete might be

 

2. Roads Made Completely Of Plastic

These roads are not made of a material mix like plastic composite roads

Instead, they are generally prefabricated off-site as as modular, hollow fully plastic elements (made from consumer waste plastic)

The pre-fabricated plastic elements are then delivered to site and laid/installed

The hollow space inside these elements can store water, allows for the laying of services like cables or pipelines

 

Plastic Roads vs Conventional Asphalt Roads – Difference, & Comparison

The differences between these types of roads might be as follows:

– Conventional Asphalt Roads

5 to 10% of the mix might use a bitumen binder (and filer), and the other 90 to 95% of the mix might be an aggregate of sand and gravel

These materials and substances are mixed together at high temperatures to make a hot mix asphalt

The mix is laid/poured on-site to form a road surface

 

– Plastic Composite Roads

Made of melted (and/or shredded) post consumer plastic, and bitumen, to form a plastic asphalt mix

Can be made of other composites of plastic too, depending on the road construction/technology used

Laid/poured on-site to form a road surface like conventional asphalt roads are

 

– Roads Made Completely Of Plastic

Made only of plastic waste

Plastic elements are prefabricated off-site, delivered to site, and then installed on-site

These roads have hollow sections where services can be run through

 

Which Countries Currently Use Plastic Roads?

wikipedia.org has a list of countries that currently use plastic roads in some capacity

What can be noted apart from the extent of plastic roads used, is the different plastic road technologies and construction methods used

Composite plastic roads appear to be most common amongst the countries that use plastic roads

 

Potential Pros & Cons Of Plastic Roads

Potential Pros

Provides a use for plastic waste material instead of going to landfill, or to another waste management option

This saves landfill space for the duration that the plastic road is in use, amongst other benefits

 

May help reduce plastic waste pollution if more plastic is kept out of the environment as a result of being used in roads

 

Might be quicker to install than conventional roads, and require less maintenance

plasticroad.com for example indicates that their product is ‘… virtually maintenance free and takes 70% less time to install and maintain [compared to] conventional infrastructure’

 

May lead to lower costs across some aspects of road installation and maintenance

medium.com indicates that plastic roads may ‘… produce lower transportation and labor costs’

 

Some reports indicate that plastic roads may last longer than conventional asphalt roads

weforum.org references that PlasticRoad products might ‘… last three times as long as a normal road — potentially as long as 50 years’

 

Some plastic road technology may help manage road flooding

For example, plasticroad.com mention that their product helps provide a solution for flooding and soft soil

A benefit of this might be that less properties are damaged from soft soil issues that arise as a result of flooding

 

The plastic roads themselves might be able to be recycled once they reach the end of their lifespan

Some manufacturers of 100% plastic roads have commented they they ‘hope’ to be able to recycle their own roads into new plastic roads in the future

 

Some composite plastic roads might be able to use different types of plastic

Because the plastic is melted down and combined with other materials, some composite plastic roads might not have the need for only one type of plastic

But, this depends on the road technology used, and the desired properties and performance of the road

 

Some reports indicate that plastic roads may have other desirable traits  

For example, e360.yale.edu notes that: ‘Research suggests that “using waste plastic in road construction helps to improve substantially the stability, strength, fatigue life, and other desirable properties of bituminous mixes, leading to improved longevity and pavement performance’

 

wikipedia.org outlines that ‘Plastic-bitumen composite roads have better wear resistance than standard asphalt concrete roads. They do not absorb water, have better flexibility which results in less rutting and less need for repair. Road surfaces remain smooth, are lower maintenance, and absorb sound better’

 

weforum.org indicates they may be able to survive a greater range of temperatures, and might be unaffected by corrosion

 

theventuremag.com indicates that plastic roads that can withstand greater temperatures may also be less prone to cracking, and may reduce the occurrence of potholes

 

Hollow plastic roads also enable services to be installed and run through the hollow space

 

Potential Cons

Is still a developing technology, that isn’t used on a large scale yet, and hasn’t been used for an extended period of time

From e360.yale.edu: ‘The technology of incorporating waste plastic into [road] paving materials is likely to take a long time to evolve. While widely in use in India, it is still in its nascent stages in other countries’

 

Using plastic roads ironically increases the dependence/reliance on plastic if more plastic is required than what can be supplied by post consumer plastic waste

The more plastic roads that are built, the more plastic is required to build them

 

Some plastic road products require specific types of compatible plastics that can perform to a certain level and have certain structural properties (that won’t lead to failure of the road’s structure itself)

As one example, MacRebur road technology ‘… [uses] a carefully selected mixture of polymers’

 

Some reports indicate that the initial cost to make and install plastic roads can be more expensive than some conventional roads

theaggie.org for example indicates that some plastics roads might be ‘… up to 30 or 50% more expensive [plus external costs]’

 

Some reports question how durable plastic roads really might be over time

Because many plastic roads have only been in use for seven years or less, e360.yale.edu indicates that there is at least questions over how long plastic roads will actually endure over time (despite what claims of their durability might say)

More evidence is needed in the future to prove that they really are more durable/last longer, and that the other claimed benefits are accurate too

 

The amount of plastic used in plastic roads may not be significant in some cases

For example, e360.yale.edu mentions that ‘When contractors add waste plastics — which can serve as an even stronger binding agent than bitumen — [to make road asphalt,] they often replace just 4 to 10 percent of the bitumen, though some methods call for much more. Plastic roads [… therefore sometimes don’t contain a significant amount of plastic]

 

Are Plastic Roads Sustainable Or Eco Friendly?

In some ways they might be, and in other ways they might not be.

Some of the factors to consider when it comes to sustainability and eco friendliness might include:

 

– Use Of Fossil Fuels

Plastic requires petroleum or natural gas to manufacture.

Asphalt/bitumen requires petroleum.

Both plastic roads and conventional asphalt roads therefore both use fossil fuels.

 

– Durability

Some reports indicate that plastic roads may last longer than conventional asphalt roads.

More durable roads means that resource inputs are needed less often to re-lay roads, and this might lower the sustainability footprint of some plastic roads.

However, some reports, such as the one from e360.yale.edu, indicate that this durability might be in question until there’s more real world data on their long term use in the future.

 

Microplastics

One concern about plastic roads up until recently has been that as they are used, and there is wear and tear, they may release plastic fragments and microplastics, which could wash off into the soil and wider environment.

However, some plastic road technologies specifically indicate that the technology is designed not to release plastic fragments or microplastics.

For example, macrebur.com indicate that there are ‘… no microplastics in MacRebur roads’

So, whether or not microplastics are an issue might depend on the plastic road technology used.

 

– Emissions

Some reports indicate that the plastic composite mix has lower emissions than a conventional asphalt mix

weforum.org has statistics on how much CO2 asphalt is responsible for, and plastic obviously replace some or all asphalt production, depending on the road technology used

theventuremag.com also notes that ‘Being mixed with plastic lowers the temperature of poured asphalt, reducing emissions’

wikipedia.org mentions that ‘The addition of plastic in asphalt can reduce the viscosity of the mix. This allows a lower working temperature, which lowers VOC and CO emissions’

 

– Toxicity

infrastructuremagazine.com.au indicates that the heating of plastic to make plastic road mixes or products may release toxic emissions:

‘Some plastics, when heated, release toxic emissions such as chloride, formaldehyde, toluene and ethylbenzene’

 

– Other

On their website, PlasticRoad indicates that their plastic road technology may lead to a maximum 72% CO2 reduction, use up to 75% less raw materials during manufacture, lead to a 80% reduction in transport movements, and contribute to the recycling of plastic.

 

 

 

Sources

1. https://en.wikipedia.org/wiki/Plastic_road

2. https://plasticroad.com/en/

3. https://www.asphalt.com.au/why-asphalt/

4. https://www.awe.gov.au/environment/partnerships/case-studies/australia-first-road-built-soft-plastics

5. https://e360.yale.edu/features/how-paving-with-plastic-could-make-a-dent-in-the-global-waste-problem

6. https://theaggie.org/2019/01/30/the-problem-with-plastic-roads/

7. https://www.weforum.org/agenda/2015/07/why-plastic-roads-could-be-good-for-the-environment/

8. https://medium.com/green-zine/can-plastic-roads-pave-the-way-to-sustainable-future-260b4909f02f

9. https://infrastructuremagazine.com.au/2019/10/28/precaution-needed-when-recycling-plastics-into-roads/

10. https://www.theventuremag.com/plastic-roads/

11. https://macrebur.com/pdfs/MacRebur_PressPack.pdf

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