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From plastic to pavement: Another example of creative waste management

Yara Salem's picture
plastic waste in Comoros
What if this “river” of plastic waste could be turned into a road to connect farmers to markets? (Photo: Farouk Mollah Banna/World Bank)

You cannot imagine my surprise while reading a BusinessWeek article last July about an innovative way to transform India’s litter into partial substitute for bitumen in asphalt to build roads!

Well, this transformative method arguably holds larger potential than the “garbage to music” recycling approach I recently wrote about in my first post about creative ways to manage waste. “Garbage to roads”  was pioneered by an Indian chemist called Vasudevan, and it could help not only in getting rid of tons of plastic litter- thick acrylics and bottles, grocery bags and wrappers-- but in building roads at the same time. It’s a win-win solution for all.

A professor of chemistry at an engineering college near Madurai in India, Vasudevan came up with this idea seeing his city’s surrounding field piled with trash. He started thinking of a way to transform unwanted and mostly non-recyclable resources into stronger roads while reducing infrastructure costs at the same time. Vasudevan calls his method “plastic to pavement technique”- waste can replace 15% of more expensive bitumen in the mix used to lay roads.

This technique holds the potential of cleaning up countries overnight given its simplicity as it does not require significant technical knowledge nor large investment or changes to existing road-laying procedures.

It has already been tested in India, where more than 5,000 kilometers of plastic roads have been laid in at least 11 states since 2004.

India is among many developing countries that sit on a plastic “time bomb” with garbage --much of which is plastic-- leaking into the soil and contaminating ground water, while also releasing dioxins and other toxic chemicals into the air, all of which carries huge environmental, social and economic consequences.

I had Comoros in mind while writing this piece as everyone who is familiar with the island talks about the tons of garbage they see the minute they arrive into their hotel room. With no sanitary landfill in sight at least in the coming few years, maybe this technique can help this small island nation in the Indian Ocean deal with this problem while addressing other critical infrastructure needs.

The good news is that this method has been gaining recognition recently; the Indian Road Congress has endorsed it. Maybe it’s a good idea for the international community, and specifically the World Bank, to look into this as part of our work on solid waste management to see if we can help countries manage their waste and its consequences while contributing to their infrastructure development. 

We can take this method to scale throughout our projects. We can start by piloting it in different countries to see where it fits best. We could help governments hit two birds with one stone.  And, with time, hopefully more alternative uses for waste can be created.

Granted, the environmental impact of this method has to be scientifically tested and validated, as well as the road sustainability. I would be interested in hearing what a reasonable timeline would be for this.

But if you think this method is of interest and holds a potential for application in World Bank Group projects, let us hear from you: Maybe one day, one of our projects can benefit from this frugal innovation ideas.

Comments

Submitted by rose on

it's a good innovation and i wish Ugandan local governments can copy a leaf from India. too much money is spent on gravel roads which get destroyed in less than a year.

Submitted by Jian Xie on

This is a very interesting and innovative approach for processing plastic waste. But there are questions and information needed in order to assess whether the approach can be applied to other places. For example, whether is the cost of collecting plastic waste included in the economic evaluation of the approach? What are the requirements for waste stream to be used in the road construction? Is there any pre-treatment cost before using the plastic waste? How flexible is the share of plastic wasted needed in the construction process?

Submitted by Frank Van Woerden on

Yara, I have no personal experience with mixing waste plastics with bitumen for road construction. As I understand, it is an concept that has pros (reuse of plastics; some possible durability enhancement) as well as cons (not all plastics are suitable, also because of environmental reasons; mixing with bitumen reduces some application properties) and that had some limited piloting / application, but has not yet developed to mainstream use.

Assuming that technical issues can be overcome, a particular point of attention is how to make contracting agencies and contractors actually use these materials. Application of secondary materials --including recycled construction and demolition waste, but also materials such as coal ash and flue gas treatment products—can entail risks and generally the sector is conservative. Therefore, in addition to solid testing, much effort is needed to get the use of secondary materials firmly included in building codes, material specs, standard contracts, etc. This aspect often needs much more effort than technically (and economically and environmentally) proving that the material is safe and applicable.

- Frank Van Woerden
Sr. Environmental Engineer, The World Bank

Submitted by Yara on

Dear All thank you so much for your comments, apologies for the delay in responding to your comments. I managed to get in touch with the inventor of this method. Dr. R. Vasudevan who shared with me his thoughts on the above. I am going to respond in one long message instead of separate one in order to provide more comprehensive view of this method. technical details are available in case you need it.

On how to use waste plastics for road construction, Carry bags, cups, thermocoles, foams and flexible films are shredded into small pieces (between 1.6mm – 2.5mm). The granite stone is heated to around 1700c. The shredded plastics waste is added to the stone. It get melted and coated over stone in just 30 seconds. Then the bitumen is added and mixed. The mix is used for road construction. From rural roads to National High ways all types of roads can be laid using this technique.

on what the main characteristics of the process are
1.Plastics waste like carry bags, disposal cups, thermocoles, laminated films and polyethylene and polypropylene foams can be used.
2.There is no need of segregation.
3.No need for much cleaning
4.Multi layer films can also be used.
5.Easy process without any new machinery
6.Simple process without any industry involvement
7.No granulation or blending is needed
8.Land filling and incineration process can be avoided
9.In situ process
10.Use of lesser percentage of bitumen and thus savings on bitumen resource
11.Use of plastics waste for a safe and eco-friendly process
12.Both Mini Hot Mix Plant and Central Mixing Plant can be used
13.Only aggregate is polymer coated and bitumen is not modified
14.Use 60/70 and 80/90 bitumen are possible
15.No evolution of any toxic gases like dioxin
16.Fly ash can also be used to give a better performance
17.Use of each ton of plastic waste avoids the entry of 3 tons of Co2 in to the atmosphere, which otherwise results in global warming
18.For 1km X 3.75m road, 1 ton of plastic (10 lakh carry bags) is used and 1 ton of bitumen is saved.
19.Value addition to the waste plastics (cost per kilogram increases from Rs 15 to Rs 30).
20.Flexible pavement scrap can be reused effectively by coating with plastics waste. This helps to reduce the cost of 50%; saves the use of raw material by 70 – 80% and also the level of the road can be maintained.

Characteristics of the Plastic Road:
- Stronger road with increased Marshall Stability Value
- Better resistance towards rain water and water stagnation
- No stripping and hence no potholes.
- Increased binding and better bonding of the mix.
- Reduction in pores in aggregate and hence less rutting and raveling.
- No leaching of plastics.
- No effect of radiation like UV.
- Can Withstand Heavy Load and Heavy traffic.

on the Performance of the Plastic oad:
Monitoring of test roads were carried out using structural evaluation, functional evaluation and conditional evaluation studies. Generally all the roads laid over a period from 2002 to 2006 are performing well. The results obtained for these roads helped to conclude that these roads are performing very well in spite of their age. Under the similar conditions most of the bitumen roads are not performing well at all. These roads have not developed even small cracking and a pothole. The roads were distributed over the different localities of Tamil Nadu exposed to various environmental conditions like temperature, rainfall, etc., yet the roads are performing well.( photos of the roads before and after are available)

on the growth of the Plastic Road:

•Patent has been obtained from the Government of India for the plastic tar road laying process – Patent No. A-CH\871; 198254
•Guidelines published by IRC-2013 IRC-SP:98-2013
Recognition:
•In the year 2010 the National Rural Road Development Agency in consultation with us, have published a Guidelines for laying plastic tar road laid
•The latest gazette notification revised plastic waste management rules mention that plastics can be used for making road by local bodies. (Ministry of Environment and forest notification ; dated 4th February 2011; P. No. 21)
•The current Chief Minister of Tamil Nadu has included in her parties election manifesto that the state will be freed from plastic menace and rural roads will be converted into plastic road using the process developed by the Thiagarajar College of Engineering.
•Tamil Nadu government implemented this process through DRDA and over 1500km rural roads were laid distributing over all the districts in Tamil Nadu.

Submitted by Gaurav on

I am a man, who believes in cash out of Trash. I had the privilege to learn and replicate this technology for Jamshedpur city in Jharkhand India. It is an easy and simple process. The lowest end plastic waste like polythene, polypropylene and polystyrene are used in the road making. First of all, we collect plastics mentioned above. Shred the plastic in the sizes 2 mm to 4 mm. While the mixing of aggregate and bitumen, sprinkle these shredded plastics in the mix at 160 deg.it gets laminated over aggregate. If you are laying a 100 meter long and 4 meter wide road, you will need 100 kg of plastics. Believe me, the road constructed using this method has got the life more than 2 times as compared to conventional road. You can see articles on Jamshedpur plastic road on Google. Let me know, if I can be of any help to any country, state, organisation, corporates etc.

Submitted by Marcus Lee on

Very interesting, thanks for sharing the info on this. I would echo Xie Jian's comments about wanting to see a full economic analysis of this, i.e. the direct costs of processing the plastic and laying roads, the indirect and external costs, the expected savings from reduced waste disposal costs and vs. conventional options for plastic recycling, comparison with the costs of conventional road materials and also longer term maintenance costs, etc.

Submitted by Pindelwa on

Very interesting concept. This would definitely hit 2 birds with one stone, taking care of waste and building roads that are most needed in many African countries.

Submitted by S.V.Raman on

I have found a way to reuse waste plastics.
It Is titled as "Waste+Waste =use"
Molten plastics 'Thermoplastics ' can be blended with agricultural wastes like Husk ,straw etc and can be made into sheets that can be used as roof tops and walls for poor people who live in thatched houses. They are "Polymer composites" .

Submitted by Dr. B G Sreedevi on

I am from National Transportation Planning and Research Centre, Trivandrum, Kerala, India. We have constructed seven demonstration stretches of length less than a kilometer each and evaluated the performance periodically and found to be very promising. We have got a shredder in our office and the plastic was collected , cleaned and shredded in house for use on roads.The results were published also.

Submitted by Skhan on

We are also faced with the solid waste problem here in our city. Though tried and tested conventional practices are visible, we are lagging behind innovation in solid waste management.
Can someone please help me understand how to work out an innovative approach in solid waste management at community level? Here I am not talking about waste treatment; I am more concerned with community level innovation in waste management, which is sustainable and ownership is maximum.

Submitted by Miras on

Thank you so much
Can you tell about recent situations with its applications?

Submitted by waste collection services on

nice information thanks for sharing really plastic is very danger for health so please avoid that products.waste collection servicesl

Submitted by Mapho Comedian on

It is a very good innovation and this will go a long way to managing plastic wastes in the developing countries.

Submitted by Vinod Bodhankar on

What is the difference between disposing plastic waste in land-fills and disposing plastic waste in road-fills? In both cases leachates are released.
In both cases the plastic will eventually turn to nano-particles and gravity will take the nano-particles to the aquifer below.
We are simply sweeping our plastic garbage under the road-carpet. By delaying the entry of nano-plastics into the environment by temporarily confining them to roads, we are using the typical human compulsion of MAKING OUR GARBAGE INVISIBLE and not caring about WHO THAT GARBAGE WILL EVENTUALLY LAND UP WITH - the future generations will have the crumbling roads with millions of tons of embedded plastics to deal with - as a SPREAD OUT ALONG THE THOUSANDS OF KM OF ROADWAYS - source of nano-plastic particles. The exposure of the road to day and night temperatures and the weight of the trucks passing over the plastic embedded roads will crumble the plastic coating on the stones - and show that road-fill is as bad as land-fill. Human beings have the compulsion to hastily apply half-researched solutions on a mass-scale. That is why we have messed up our environment.
As long as it is known that nano-plastics are hazardous to the environment - the road solution is no solution but an avoidance of a true solution.

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