The abundance of plastic waste dumped in the environment and its harmful effects call for an urgent action. In response, many countries have actively taken up the responsibility of recycling as much plastic as possible. There are different ways of utilising the recycled plastic, one of them is to utilise it for the construction of roads.
India is one of the few countries which has already started the use of recycled plastic in road construction from the past few years. In fact, a government order in November 2015 made it mandatory for the road developers in the country to make use of plastic waste alongside bituminous mixes for road construction. On the other hand, some similar projects are being initiated by other countries as well.
Viability of the Idea
Plastic being used in the road construction (Image Courtesy: indiatimes)
Plastic is a material created by man but it’s also something that can’t be destroyed. A majority of the waste created by humans contains plastic waste which ultimately chokes stray animals to death, clogs drains and only leads to mess. The clogged drains lead to flood while the plastic in the fields blocks germination, thereby preventing rainwater absorption.
Considering the complexity, it seems like a perfect solution to put plastic in the heated bitumen and coating mixture and use it for road construction. But how practical is it? Well, the answer is quite positive. Although some may point out that spreading a material, which is harmful to environment, on the roads can be even more disastrous; the truth is that many roads built in India over the past few years have laid down plastic waste on the lanes without any issues being reported.
How is it Different from the conventional method?
View of an Indian road constructed out of Plastic Waste (Image Courtesy: thebetterindia)
Laying down one km of normal bitumen road takes 10 tonnes of bitumen, while the use of recycled plastic can build a 3.75-meter wide road by utilizing 9 tonnes of bitumen and 1 tonne of plastic waste for every km. Interestingly, 1 tonne of bitumen costs INR 50,000 to INR 60,000 (in India). So for every 1 kilometer, you get to save thousands of rupees.
Besides, 1 tonne of plastic waste equates to 10 Lacs carry bags and hence people are required to sell off the plastic which they use for domestic purposes. This has even led to thousands of people getting involved in collecting and shredding plastic waste.
Process of Road Construction Using Plastic Waste
Collecting Plastic Waste: The first step involves a collection of items categorized as plastic waste. It includes carry bags and cups with 60 microns of thickness, hard and soft foams, laminated plastics like biscuits and chocolate wrappers.
The collected plastic is cut into a size of 2.36 mm to 4.75 mm by using a shredding machine.
The aggregate mix is then heated to 165 to 170 Degree Celsius and transferred to a mixing chamber whereas the bitumen is heated up to 160 Degree Celsius to prevent weak bonding.
At the mixing chamber, the shredded plastic gets coated uniformly over the aggregate within 30-60 seconds and shows an oily look.
The plastic waste mixture is combined with the bitumen mixture and the resulting aggregate is used for constructing the road between 110 to 120-degree celsius.
Plastic Road Projects:
Worldwide, there have been independent attempts to bring a change to the method of conventional road building while making the best use of recycled plastic waste. Listed here are some of these prominent projects that have been initiated and implemented till date.
1. Initiatives Taken by the Plastic Man of India:
Prof. Rajagopalan Vasudevan, the Plastic Man of India (Image Courtesy: thebetterindia)
Prof. Rajagopalan Vasudevan, the Dean and Head, Department of Chemistry, Thiagarajar College of Engineering (TCE), Madurai, is known as the Plastic Man of India for introducing a revolutionary solution to plastic pollution. In the year 2002, he laid down the first plastic tar road within the college campus that has remained intact till date. Even though TCE holds the license to this technique, it is often licensed for free. The same technique has been adopted by Central Pollution Control Board and the Indian Roads Congress.
Till date, more than 3,000 miles of roads have been laid down in 11 states of the country using the shredded plastic waste. He has even developed a plastic monoblock technology which makes use of just plastic and stones at high temperatures to build monoblocks, with a loading capacity of 300 tonnes.
2. KK Plastic Waste Management
While the above attempt by Prof R Vasudevan was made to develop the technology, another attempt has been made by a company named KK Plastic Waste Management Limited in order to take care of the recycling. It’s the only company with an exclusive patented technology of reusing plastic waste for road construction since 2002.
The company owns plastic recycling plants in Bengaluru that process up to 30 metric tonnes of plastic on a daily basis. The organisation is responsible for collecting plastic waste from all the possible sources, undertaking contracts and then supplying the product to the authorities which make use of that mix in the construction of roads.
3. The PlasticRoad Consortium
The PlasticRoad Project (Image Courtesy: plasticroad)
The PlasticRoad Project is a group effort where the aim is to design each and every required component of the road with as much recycled plastic as possible. As opposed to the previously mentioned methods where the plastic waste was mixed with bitumen, here the approach is to build hollow spaces out of recycled plastic. The project is an outcome of a partnership between three companies namely:
• KWS: It’s the market leader in producing asphalt in the Netherlands as well as road construction. It’s engaged in constructing large, complicated, and multi-disciplinary projects alongside small projects for government and individuals.
• Wavin: It’s the European market leader in supplying plastic pipe systems and also offers a wide product range for sustainable rainwater management.
• Total: It’s the global energy producer and provider, a leading oil & gas company and world’s second biggest solar energy operator with SunPower. It deals with oil & gas production, refining, petrochemicals, and marketing.
In this project, the aim is to build pre-fabricated and hollow spaces and lay them down in the form of blocks for road construction. Moreover, in case the plastic isn’t found to provide the required stiffness, the plan is to use add sand or crushed stone to the mix.
• The project claims that the plastic roads will feature:
• 70% faster road construction
• Dual use of hollow space for cables, pipes or water storage
• Little or no maintenance
• 3 x longer expected lifetime of the roads
• 4 times lighter than the traditional road structure
Even though the partners have announced the project in public, they still have to wait to prove if the idea is feasible enough and the aim is to build a prototype by the end of this year. The idea has also received some criticism for not being practical enough due to the nature of plastic and its unsuitable properties, the project still has a chance to change the way people think about road construction.
Plastic is a non-biodegradable waste and using it as for road construction can actually solve various problems at a global level. With the advancement of technology and engineering techniques, nothing seems to be impossible. Till now, it’s quite clear that human has ruined the environment in every possible way through the overuse of technology and now it would be interesting to watch as to how he uses the same technology to fix the problems that he created.
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