We’ve talked about how plastics are changing automobile manufacturing, making cars lighter, more affordable, and more fuel efficient. However, automotive injection molding and thermoforming aren’t the only ways plastics are changing how we drive. Roads in the UK, Australia, and even Los Angeles are now being paved with “plastic asphalt,” so we’re taking a closer look at it. What is plastic asphalt? Is it effective and safe? What are the pros and cons? We’re diving into all of it.
A Look at Traditional Pavement
Before we look at innovations in road paving materials, let’s consider what is traditionally used. When you think of road and parking lot material, you’re actually thinking of asphalt concrete, also called pavement or blacktop. What’s poured out of trucks and rolled onto the road is primarily an aggregate of sand and gravel, held together by asphalt which is the black, highly viscous petroleum product, called bitumen that is used as a binder.
As temperature changes, UV rays, moisture, and traffic pressure wear down the pavement, it breaks down, forming cracks and potholes. Over time, it needs to be replaced, and more departments of transportation are using milling machines to take up the old pavement, grind it up, and keep it for recycling while pouring fresh asphalt concrete. Though most pavement that’s laid down is recycled, scientists and research teams are looking at how the paving process can be made more sustainable, including how to do on-site recycling, increase longevity, and decrease the mining of bitumen deposits or using the leftovers from refined oil. One way to do this is to use plastic waste as the binding material with milled asphalt concrete.
What Is Plastic Asphalt?
Developed by MacRebur, a UK-based company, plastic asphalt replaces bitumen or petroleum-based asphalt with plastic waste, specifically water bottles, soda bottles, and single use plastic bags. The plastic is sorted by polymer structure, such as plastic bags in one group and bottles in the other, and each group is pressed into pellets that vary in how durable and pliable they are. By mixing plastic pellets with hot, milled pavement, it melts into the aggregate and acts as the binding agent.
While traditional pavement is ground up and reused at a later time, using plastic waste allows for an immediate recycling process. The pavement is milled, pulled into the machine, and is mixed with melted plastic on-site, creating a road that is not only 100 percent recycled, there’s no “turn-around” time for recycling. What’s taken up is reused immediately, eliminating the need to carry and store old asphalt concrete to use at a later time.
In addition to MacRebur, who is using this method across England, Scotland, and Australia, TechniSoil Industrial is innovating this method and putting it to work in California.
Pros and Cons of Plastic Roads
Now that we know what plastic asphalt is, and that it’s not actually a road made totally of plastic, let’s look at the benefits and drawbacks of using plastic waste in road material.
- Minimizing plastic in landfills, oceans, and rivers;
- A cheaper alternative than using asphalt;
- Reducing carbon emissions by not having to haul or store asphalt aggregate for recycling;
- Save time by recycling during use;
- As durable or more durable than traditional hot mixed asphalt;
Overall, it looks like using plastic in road materials leads to a cost-effective, eco-friendly way to improve the infrastructure. But is it all good news?
The only main concern most experts have with using plastic in road paving is the concern of spreading microplastics and polluting the air.. Heating plastics can often release toxic fumes, but MacRebur is insistent that because PET and PVC are excluded and the temperature is highly controlled, the plastic isn’t giving off fumes during the process.
Learn More About Automotive Plastics
We are excited to see how plastics can improve infrastructure while minimizing waste and while our thermoplastics aren’t used in road paving, they are used in construction equipment, automotive manufacturing and multiple other industries. If you’re interested in having custom plastics manufactured for your company, reach out to our team today. Our injection molding company works with all types of industries in the Southeast and Mid-Atlantic, including North Carolina, South Carolina, Pennsylvania, Maryland, Tennessee, Georgia, and Virginia.