Plastic roads! the best way to recycle plastic

Overview:

      Since the invention of plastics, earth has been polluted to extents beyond recognition. Plastics have amalgamated with our daily lives so much so that we need them in every nook and corner of our day to day activities. So, what makes plastics so widely usable? First of all, they are highly cheap and can be manufactured easily; one of their main property is that they are waterproof which makes it desirable in almost all fields. But on the other hand, when they pile up as a waste, they make up for a deadly waste that doesn't decompose for thousands of years. This makes plastics formidable considering the disasters it can inflict upon earth, for example: soil pollution, water pollution, air pollution when they are burnt, contaminating the wild life habitat and many more.

 

      Thus, one of the ways to get rid of the ill effects from plastics is to recycle them; India is the 7th largest country in the world and what better way to use recycled plastics other than constructing roads in India! Yes! the plastic roads have slowly made their debut in India and is gaining popularity at snail's pace. In this blog, I'll be writing about the plastic roads, how are they implemented and its pros and cons.

Plastic Roads:

     As the name suggests, these are roads that are built up using the waste recycled plastics. There are two kinds of plastic roads:

• Complete plastic roads: Built purely out of plastics that are recycled.
• Composite plastic roads: Built using plastics and other composites added with it.

     Plastic roads are different, compared with respect to that of standard roads that are built using bitumen (asphalt) concrete, which consists of mineral aggregates and bitumen( is a sticky, black material, and highly viscous liquid or semi-solid form of petroleum). Although, currently there are no records of regular roads made out of pure plastic. 

      Plastic road features numerous advantages compared to conventional roads, both in terms of construction and maintenance. Plastic is much more sustainable and opens the door for a number of new innovations such as power generation, quiet road surfaces, heated roads and modular construction. Additionally, the Plastic road design features a 'hollow' space that can be used for cables, pipes and rainwater. Moving further let us look in to the construction of these plastic roads.

Building the Plastic roads:

       The very concept of plastic roads is relatively new in India and countries similar to it. For example in Jamshedpur, India, roads are built by composite method, mixing plastic and bitumen. Since these roads are made from plastic at its core, these steps are followed in general:

A plastic road in India made by JUSCO

 

• First, post consumer used plastics and other plastic wastes are accumulated
• Most common plastics procured are polyethylene teraphthalate (PET or PETE), polyvinyl chloride(commonly known as PVC), polypropylene (PP), etc.
• Second step is to sort the above pure form of plastic from plastic wastes.
• After sorting, materials are cleansed, dried and shredded. 
• The shredded plastic is then mixed and melted at 170℃ and hot bitumen is added to melted plastic.
• After mixing, the mixture is laid on the road same as done with regular asphalt concrete.

Now lets look in to the pros and cons of plastic roads.

Pros: 

• One of the huge advantage of plastic roads is that, they can be hollow constructed to accommodate wiring, pipelines and cables that run through the city.

• Heating and power generation can be incorporated into plastic roads. Heating can prevent roads from freezing; it can also help evaporate water from the surface.

• Since plastics come with various chemical and physical properties, roads engineered from them would be resistant to changing weather conditions.

• Plastic waste mixed in at 8% ratio to asphalt world-wide may solve the issue of plastics in landfills and oceans world-wide, soon becoming more valuable as a commodity..

• Plastic roads can be made into interlocking pieces that can be quickly assembled or disassembled. This makes on-site construction much faster and convenient. Simplicity and speed of road work also correlates to lower cost.

• Plastic-bitumen composite roads need not be especially discriminating with the plastics used, thus increasing the reuse of plastic.

• Using less asphalt(bitumen) adds to saving resources because, bitumen concrete requires petroleum which is becoming more scarce.

• The use of plastic in road construction reduces the amount of asphalt used. This is beneficial to the environment since asphalt is responsible for 2% of global carbon emissions.

• Modular plastic pieces are much easier to work with than asphalt.

• 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.

• 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 of lower maintenance, and absorb sound better.

• Cost effective: using recycled, post-consumer plastics is cheaper than using asphalt.

Cons:

• Pure plastic road requires using compatible plastics because, when melted, plastics of different types may phase-separate and cause structural weaknesses, which can lead to premature failure.

• Wear on the surface of 100% plastic roads creates harmful plastic particulates which can worsen current micro-plastic pollution problem.
• On purely plastic built roads, the friction provided by the road for tires to have grip is yet to be tested practically.