What’s all the fuss about Plastic roads? - Read along
Recently, the news of inauguration of a plastic road in Islamabad's F9 park was making rounds. It left many dumbfounded as to how can roads be made out of plastic and what are we doing so? Well we decided to write an article on this to answer all your queries.
In order to practice a circular economy: Reduce, reuse, recycle, plastic roads are the future as they offer a smart and sustainable alternative for infrastructure solutions.
Making roads utilizing plastic can make a significant dent in the global waste dilemma along with stronger roads with increased Marshall Stability Value. Instead of a landscape that reeks owing to a sea of plastic litter, we can get roads with plastic as a fundamental component.
The world’s most plastic waste ends up in landfills, oceans, or the incinerator which is the impetus to strive for a circular economy resulting in a world without waste. Although this is only one method for the divergent array of uses for waste plastic, it can significantly reduce the impact.
Roads in which waste plastic is melted down and mixed with paving materials are becoming more common around the world. Although for now, they remain a niche technology, experts say the roads could become one of the diverse uses for discarded plastic.
What Makes Plastic Roads Different?
To make plastic waste a part of the road, a slurry of discarded plastics is used in the asphalt to make the roads. This niche technology doesn’t use very high-tech machinery making it a very simple and minimal process. The shredded plastic waste which mainly consists of polyethylene and polypropylene foams, plastic carry bags, bags (PETs), bottles, snack wraps, and disposable cups is first melted at 170C.
The melted material is then used to cover the aggregate in a very thin film. This mixture is a far stronger binding agent than even bitumen which is universally used for binding the aggregate together.
Advantages of Plastic Roads
Not all plastic can be recycled which leads to its accumulation in mainly landfills and oceans. The fundamental reason behind building plastic roads is the disposal of non-recycled plastic. Undoubtedly, the use of discarded plastic material to make roads is one of the best methods for easy disposal of waste plastics.
Moreover, plastic waste treatment is very time-consuming and dangerous for the environment as the burning of plastic leads to carbon emissions in the atmosphere.
Making plastic a part of the roads will not only solve the issue of plastic discharge with litter-free roads but it will also give us stronger roads with more durability and a longer life span. Large quantities of plastic waste are needed for a small portion of the road; thus the wastage will drastically decrease.
Longevity and Durability
The use of plastic in the aggregate makes for a stronger and more durable road with increased Marshall Stability Value. The longevity of the roads undoubtedly increases with more stability and strength. The plastic roads that were developed some decades ago are still in pristine condition with little to no maintenance.
However, their long-term durability still remains to be seen as plastic roads are a novel invention. How will plastic roads age is still a very big question as most plastic roads all over the globe have been built in the last decade?
The incorporation of plastic in roads makes them function a whole lot better as almost no potholes are observed in them. It minimizes the deterioration process which leads to stronger roads with no potholes.
Building roads with plastic can be cost-saving too. In India, plastic roads saved around $670 (£480) per kilometer of road. This can solve the issue of the lack of monetary funds to build roads in the rural areas of Pakistan.
Since plastic roads require little maintenance as they offer, better resistance towards rainwater and water stagnation. This saves a lot of money too.
Resistance towards Water and Weather
Plastic roads have greater resistance towards natural calamities i.e. rainwater and cold weather. Thus the innovation is considerably more cost-efficient as the roads are virtually impervious to conditions such as the weather and weather.
Since a large amount of plastic waste is required for a small stretch of road, the amount of waste plastic strewn around will definitely reduce.
Disadvantages of Plastic Roads
Concerns about Carbon Emissions
Although the biggest advantage of incorporating waste plastic is the sustainability factor as the processing of petroleum-based asphalt releases a large amount of greenhouse gas emissions.
However, there are some concerns about the carbon emissions caused by the burning of plastic to make asphalt. Therefore, it is mandatory that the plastic is heated at 170 degrees Celsius (338 degrees Fahrenheit) to prevent gas emissions.
According to environmental scientists, plastics when burned at 270 degrees Celsius or higher release harmful gases. Thus, we should stay in the aforementioned safe range to avoid that.
The Dilemma of Micro Plastics
The biggest source of microplastics in the world is the abrasion from tires. Some believe that plastic roads can also contribute to microplastics on the planet. Others counter the argument by making a statement that roads are made of inert material and there is a very minor chance of this happening.
There is a possibility of leaching during the making of plastic roads. During the cleaning phase, it is predicted that the harmful toxins in the commingled plastic would trigger leaching.
It is also possible that after the road has been laid, the first rain can start the leaching process as the plastic layer merely forms a sticky layer to protect against mechanical abrasion.
The Future of Plastic Roads in Pakistan
This technology is still in its nascent stages in Pakistan. The Capital Development Authority (CDA) recently announced the plans to build a plastic road in Islamabad to take a step towards sustainability.
This eco-friendly round will be built in the F9 Park in Islamabad spanning one km while constituting recycled plastic material from more than one million plastic cups. According to the CDA spokesperson Rana Shakeel Asghar, the first plastic road in Pakistan will be functional soon.
Although this initiative started out in the capital city, the government plans to extend plastic roads all over the country as the durability, sustainability, and cost-effectiveness are unparalleled.
The longevity, water-resistant quality, and increased resistance to extreme climate conditions of plastic roads give us enough incentive to make them prevalent in Pakistan.