2. Varun Suriyanarayana
CONTENTS
RESEARCH QUESTION.............................................................................................................................3
ABSTRACT ...............................................................................................................................................3
HOW ARE ROADS MADE? ......................................................................................................................4
COMPARISON OF TYPES OF ROADS IN USE TODAY ..............................................................................5
Bitumen/Asphalt roads:.....................................................................................................................5
Tar road: .............................................................................................................................................5
Concrete Road:...................................................................................................................................6
WHAT ARE PLASTIC ROADS?..................................................................................................................6
TYPES OF PLASTICS USED IN PLASTIC ROADS........................................................................................7
TWO PROCESSES USED IN THE CONSTRUCTION OF PLASTIC ROADS...................................................7
Wet Process:.......................................................................................................................................7
Dry process:........................................................................................................................................7
CONSTRUCTION OF PLASTIC COATED BITUMEN ROAD........................................................................8
SIGNIFICANT FEATURES OF THIS PROCESS............................................................................................9
Durability............................................................................................................................................9
Environmental advantage................................................................................................................12
Economic advantage ........................................................................................................................14
Safety advantage..............................................................................................................................15
CONCLUSION ........................................................................................................................................15
BIBLIOGRAPHY......................................................................................................................................17
3. Varun Suriyanarayana
RESEARCH QUESTION
Should plastic roads be the preferred option in road construction for highly populated
countries?
ABSTRACT
Challenges are a way of life. From challenges arise the endeavour to find solutions. Two
such challenges that countries with large populations face are effective disposal of plastic
waste and establishing a road network that is economical and durable. On the face of it, it
appears odd to bring up two matters, so different in nature, together. However, there is a
solution that connects the two problems. Current methods adopted to deal with plastic
waste disposal worldwide include use of landfills and incineration. Both methods are
known to have environmental and safety concerns. Today the majority of roads are
constructed using either bitumen, tar or cement. Each of these have their own merits and
demerits. Another kind of road has been suggested: plastic road. This provides a solution to
the problem of effective disposal of plastic waste at the same time increases the strength
and durability of the road, addresses the environmental, economic and most importantly
safety issue.
INTRODUCTION
Our rapid advances in technology have done much to improve our quality of life and our
environment but in the process we have also produced a number of issues. Two such issues
are plastic waste disposal and establishing a road network which is both economical and
durable. Every year the world produces 275 million tonnes of non-recycled non-
biodegradable plastic waste.[6] The problem of disposing this plastic waste has been around
for several years and all the solutions that have been implemented on a large scale have
flaws, both environmental and economic. On the other hand, growth and development of
an economy has always been intrinsically dependent on transportation via a presence of a
reliable and extensive road network. Most developing countries often encounter problems
in the quality and durability of their roads and this in turn impacts the economy significantly.
India, a country with the second largest road network in the world with 4.7 million
kilometres of roads as of May 2, 2014, is no exception.[30]
Dr. R Vasudevan of the Thiaragar college of engineering in Madhurai, India came up with a
solution to build roads by integrating a fraction of plastic waste into the Bitumen and
aggregate mixture. His idea has been implemented in a number of places across India. The
first plastic road was laid in Kovilapatti of Tuticorin district on October 4th 2002. In order to
understand how they are a solution to today’s problems one must first understand what
they are and how they are built.[24] This paper will examine what a plastic road is, how it is
built, its environmental implications, economic impact and finally safety features.
4. Varun Suriyanarayana
WHAT ARE ROADS?
According to the Organisation for Economic Co-operation and Development (OECD), a road
is a “Line of communication (travelled way) using a stabilized base other than rails or air
strips open to public traffic, primarily for the use of road motor vehicles running on their
own wheels.”
Pharaoh Cheops is believed to be credited with the building of the first road around 2500
BC. This road was 1000 yards long and 60 feet wide and led to the site of the Great Pyramid.
It was put in place for making the pyramid and later visiting it. With time, more and more
roads were made to promote trading.
HOW ARE ROADS MADE?
Bitumen and Tar roads are laid in several stages. The land on which the road is to be built is
cleared of all vegetation. All rocks and stones are removed. Ditches, basins and fences are
installed to prevent erosion on the land that has been cleared. Then bulldozers and diggers
are used to mount soil and dirt onto the land. Drains made from concrete pipes are also
installed to ensure that rainwater does not flood the road. After this the road is graded or
levelled. This requires a combination of manpower and machines. In order to ensure that
the levelling is stable, concrete or limestone is used. This grading process is repeated before
a stone aggregate base layer is added. This aggregate consists of crushed stone or gravel or
granite. The layer is evenly placed and if the road is in a city, a gutter will be constructed
right after the stone aggregate is placed. After this the road is graded again. Then up to 4
layers of Bitumen are applied one at a time and the final touches on the drainage system
are made just before the final layer of Bitumen is added. After this the road is left to set.[1]
The Bitumen acts as a binding agent and seals the aggregate to form a smooth surface on
which vehicle can travel.
Concrete roads on the other hand require the concrete mix to be prepared in the ready mix
plant from where it is transported to the site where the road is to be laid. It is then poured
into a frame work that defines the final size and shape. Once poured the concrete must be
consolidated. This ensures that all air voids are removed and the concrete is evenly
distributed all over the framework including nooks and corners. This process is also referred
to as Compacting. This is followed by Finishing. Finishing provides the road with a smooth,
durable and appealing surface. The final step is Curing. This is ensuring that the concrete is
fully saturated while hardening. Once properly cured, the concrete develops the requisite
properties which make it stronger and more durable.
5. Varun Suriyanarayana
COMPARISON OF TYPES OF ROADS IN
USE TODAY
There are 3 major types of roads that are used today. These are Bitumen/asphalt roads, tar
roads and concrete roads.
Bitumen/Asphalt roads:
These roads are made using Bitumen and a stone aggregate. Two kinds of stone used are
gravel and granite. The Bitumen is a substance derived from crude oil. It is a hydrocarbon
that is semi-solid. It is obtained by refining heavy crude oil. It is the residue obtained by
fractional distillation which removes lighter fractions such as kerosene, naptha, gasoline and
diesel. 85% of the 102 million tonnes of Bitumen produced per year is used for paving[21].
Bitumen is obtained from crude oil, which is a depleting natural resource. The cost of
constructing these roads varies from 20 - 30 lakhs per kilometre (km) for a single lane.
However, very often these roads do not score high on strength and durability. They are
affected by weather conditions. In the summer, high temperatures cause Bitumen to
become soft which results in bleeding, rutting as well as segregation and finally breaking
down of the road. On the other hand in winter, low temperatures cause the road to become
brittle resulting in cracking, ravelling and unevenness, rendering the road unsuitable for use,
in the monsoon, when the rains are heavy the water enter the road creates potholes and
sometimes removal of the Bitumen layer. In mountainous and hilly places where
temperatures drop to below zero degrees, the freezing and melting of ice in the bituminous
voids causes the water to expand and contract. This damages the road. [27]Fuel or oil leakage
from vehicles can also cause damage. [23]
On the positive side, Bituminous roads cost around 25% less than concrete roads. They are
very easy to repair and they also score higher on safety as they have more skid resistance in
wet conditions, than concrete roads. The Bitumen used is recyclable, the process of laying
the road is carried out on site and since there is no industrial process required, it is simple
and convenient. Construction poses no risk.[23]
Tar road:
Tar roads are largely similar to Bitumen roads except for the fact that tar is used instead of
Bitumen. Tar is similar to Bitumen in appearance in that it is black and sticky. Tar is
produced from coal. When coal is heated to high temperatures it forms coke and carbon
dioxide. Tar is a by-product. It was used as the binding agent but has over time been
replaced by refined Bitumen.[20]
Tar is obtained from coal, which is a depleting natural resource, the road does not perform
well in high temperature conditions. Tar does not lend itself to even levelling as a result fuel
efficiency of vehicles travelling on Tar roads is less. The biggest concern with the tar road
arises from the fact that it poses a cancer risk for those who work to construct it.[23]
6. Varun Suriyanarayana
On the positive side Tar roads cost 40% less than Bitumen, they also set quickly and take less
time to put in place. They are more durable than Bitumen roads and need less maintenance
than Bitumen roads and like Bitumen roads are easy to repair. They are somewhat rough
and hence have the highest skid resistance of the three types of roads. Tar is recyclable and
the road is not easily damaged by oil or fuel leakages from vehicles.[23]
Concrete Road:
The concrete comprises of a mixture, an aggregate, water and chemical additives that may
be necessary to give it the desired properties. Once the concrete is mixed, it is transported
to the location where it will be used. At this location it will be poured on the framework that
reinforces it. After this it is consolidated to remove any air voids. Once this is done the
concrete is finished by smoothing it with a blade of sufficient width. Finally it is left to cure
and set. The concrete road is different from the others in that there is no stone aggregate
base used. There is a framework instead. [20]
The concrete road has a higher cost of construction and takes much longer than a Bitumen
or tar road to put into place. The concrete is not recyclable. Even though it requires very
little maintenance the process of repair is a complex one, the damage section of the road
cannot be repaired in isolation, the entire slab has to be replaced. This makes the process of
repair cumbersome, more expensive as well as more time consuming than the Bitumen and
Tar roads. To add to this in wet conditions the road is unsafe and accidents can be caused by
skidding vehicles.[23]
On the positive side a concrete road is made using lime stone which is abundantly available
lasts up to 40 years. Even though it costs 25% more than Bitumen roads it is far more
durable than Bitumen roads and requires very little maintenance, this balances the fact that
more time and money are needed to build the concrete road. They can withstand extreme
heat, cold, rain, snow, and water logging. They are not affected by fuel leakages. Since they
do not suffer damage they increase fuel efficiency by 14 – 20%[27]. They are not affected by
fuel or oil leakages. Construction poses no risk as is the case in tar roads.[23]
The comparison indicates that the best option is the concrete road. However a fourth kind
of road was suggested by Dr Vasudevan in 2001 – The Plastic Road.
WHAT ARE PLASTIC ROADS?
Traditionally the construction of a bitumen or tar road is initiated by laying a base layer of
aggregate. This aggregate comprises of crushed stone or gravel which is spread evenly over
the area that is to become a road. On top of this, up to 4 layers of Bitumen are applied.[1]
The plastic road requires the addition of 5-10% of plastic waste to heated aggregate for 30-
40 seconds before the addition of the heated Bitumen. The final road obtained was found to
be superior to the conventional road in a number of ways. This process effectively uses a
substantial amount of plastic waste.[2] This road, called a plastic road, is more durable, more
economical and environmentally beneficial. [3]
7. Varun Suriyanarayana
TYPES OF PLASTICS USED IN PLASTIC
ROADS
The most commonly used plastics in this process are polyethylene, polystyrene, polyester,
and polypropylene. Polyethylene can be made in 3 different ways. Each of these 3 different
ways results in polyethylene with different properties. Hence each one is given a slightly
different name. Low density polyethylene is normally used to make plastic bags. High
density polyethylene is used to make plastic chairs, dustbins, bowls etc. Linear low density
polyethylene is used to make plastic sheets and wraps. Polystyrene is typically used in fast
food cartons and as insulation. Polyester (Polyethylene terephthalate) is mainly used as a
fabric for clothes. Polypropylene is used for clothing and is applied in radio controlled toy
planes. All of these plastics, upon incineration liberate large amounts of carbon dioxide and
water if sufficient oxygen is used, otherwise, carbon monoxide is produced along with
water. Polyvinylchloride (PVC) cannot be used because upon heating it can release dioxin
which is toxic gas[25].
TWO PROCESSES USED IN THE
CONSTRUCTION OF PLASTIC ROADS
Wet Process:
In this process, the waste plastic is directly mixed with hot Bitumen at 1600C and this
mixture is then mixed using a mechanical stirrer. This mixture also contains additional
stabilisers and requires proper cooling. It is not popular because it requires huge
investments, larger plants and more equipment than the Dry Process.[26]
Dry process:
First the plastic waste is collected, segregated and stored[2]. The segregation is done
because certain kinds of plastic like polyvinyl chloride (PVC) and flux sheets cannot be used
due to safety concerns[4]. The next step involves the cleaning of the plastic. This is necessary
because most of the plastic waste collected has been used for packaging (55% in India)[3]
and hence is likely to contain residual substances such as little bits of food which must be
removed. After this the plastic goes through the process of shredding which reduces it to
the correct thickness, 2-4mm. [2]
The aggregate is heated to around 1600C-1700C and then the plastic is added and after 30-
40s a uniform coating is observed. This coating gives it an oily look. The Bitumen is then
added and the mixture is thoroughly mixed before laying. The Bitumen is added at a
temperature of around 1550C - 1630C[2]. This temperature is carefully regulated to make
sure that the binding is strong[5]. The process is described by the diagram below.
8. Varun Suriyanarayana
CONSTRUCTION OF PLASTIC COATED
BITUMEN ROAD
[32] [33]
Plastic waste collection Plastic waste is segregated
[35] [34]
Plastic waste is (shredded to 2-4mm Plastic waste cleaned and dried
[37] [36]
Stone aggregate heated to 1600C-1700C Shredded plastic added to
heated aggregate ‘ for 30-40s for
uniform coating
[39] [38]
Up to four layers of the mixture The Bitumen (temp. 1550C-
1630C) is then is laid rolled and cleaned ‘ added and mixed
with the coated aggregate
[40]
A final layer is added and rolled before being left to rest[2]
9. Varun Suriyanarayana
SIGNIFICANT FEATURES OF THIS PROCESS
1. Durability
2. Environmental advantage
3. Economic advantage
4. Safety advantage
Durability
The normal Bitumen roads in India tend to break down very quickly. This to a large extent is
due to the high temperatures prevalent in some parts of the country. However even in the
best of conditions in India, roads often break down within 5 years. Dr. Vasudevan conducted
a number of tests which illustrate that the durability of the plastic road will be significantly
higher.[3]
Binding test
This test measures the bending strength and the compression strength of the mixture used
to make the road. Bending strength refers to the mixtures ability to resist deformation
under heavy load. Compression strength refers to the mixtures ability to resist forces that
attempt to compress or squeeze it. [48]
For this test the hot mixture was compacted using a compacting machine and then
compressed using a universal testing machine. The test was done for mixtures with 10%
20% and 25% plastic and the test was repeated using different plastics. The results illustrate
that the greater the proportion of plastic the greater the bending strength and the greater
the compression strength. For example with polyethylene the bending strengths were 325kg
340kg and 350kg at 10% 20% and 25% respectively while the compression strengths were
250 tonnes 270 tonnes and 290 tonnes respectively. [3]
10. Varun Suriyanarayana
Moisture absorption test
The moisture absorption test is done to determine the extent to which the aggregate
absorbs water. If the water absorption is high the road is likely to break down and develop
pot holes in the event of any water logging.
In order to determine how resistant the road is to water absorption a fixed mass of the
mixture was taken and immersed in water. After 24 hours the mixture was removed and
reweighed. The difference in mass was the mass of water absorbed. This was identified for
plastic concentrations of 0%, 1%, 2% and 3%. The moisture absorbed has been quoted as a
% of the mass of the mixture added. The results were 4%, 2% and 1.1% for 0%, 1% and 2% of
plastic added. For 3% plastic only negligible amounts of water were absorbed. This indicates
that the plastic makes the mixture less susceptible to moisture.[3]
Soundness test
This test measures the mixture’s resistance to weathering by conducting tests that simulate
weather cycles in an accelerated manner. The weathering occurs because when water
enters pores and voids in the mixture, the salts dissolved in the water, crystalize. When the
water evaporates more crystal is formed and this crystal causes the mixture to crack and
break. The freezing and thawing can cause the porous aggregate tends to disintegrate
prematurely.[47]
The test conducts 5 accelerated weathering cycles and measures the mass of the mixture
that was lost. The % mass lost should not exceed 12% when sodium sulphate solution is
used. Just like in the test for moisture, 0% 1% 2% and 3% plastic were used. The results
indicated that the % lost for the 0% plastic (plain aggregate) was 5% ± 1% but for 1%, 2%
and 3% plastic no mass loss was observed. This suggests that the plastic in the mixture
increases the mixture’s resistance to weathering. This could be explained by the fact that
the % voids in the mixture decreased as the % plastic increased. The values were found to
be 4%, 2.2% and 1% for 0%, 1% and 2% plastic while for 3% plastic no voids were observed.
[3]
11. Varun Suriyanarayana
Aggregate impact test
The test is used to determine the aggregate’s resistance to fracturing. It measures the ability
of the road to resist impact or to measure how tough the road is. Continuous movement of
heavy vehicles on the road subjects them to nonstop impact causing it to disintegrate.
Often, to begin with, it resembles a crocodile skin before completely breaking down.
In order to measure this a sample of the mixture is taken and hit with a 14 kg hammer 15
times. The % of mass that becomes powdered should not exceed 30%. The powdered mass
will be identified as the mass passing through a 2.36mm sieve. The experiment was
conducted for 0%, 1%, 2 % and 3% of plastic and the results were found to be 25.4%, 21.2%,
18.5% and 17% respectively. This suggests that the plastic makes the mixture less
susceptible to fracturing in the event of a large force. [3]
Los Angeles abrasion test
The test used is the Los Angeles abrasion test. This test measures how resistant the
aggregate used in the road is to abrasion. Soil particles present in the tyres of the vehicles
and the on the road result in abrasion of the road as the vehicles move on the road. This
test measures whether the road aggregate is hard enough to withstand abrasion. [46] This is
measured by rubbing the mixture with steel balls. This is done by placing the mixture on a
1.70mm sieve inside a rotating drum. A fixed number of steel balls were rotating in circular
fashion at a rate of 30-33 rpm until 500 revolutions had been completed. The mixture was
placed at a particular point on the circumference such that as each steel ball passed it
rubbed the mixture. The % mass passing through the sieve should be less than 30%. The
experiment was conducted for 0%, 1%, 2%, 3% of plastic and the % mass passing through
the sieve were found to be 37%, 32%, 29% and 26% respectively. This suggests that the
12. Varun Suriyanarayana
plastic coating improves the resistance to abrasion significantly and is essential in order to
bring it below the 30% value. [3]
Environmental advantage
Our daily lives are inundated by the use of several products containing plastic in some form
or the other. Its annual production amounts to over 275 million tonnes globally and India
alone as a consumer accounts for over 11 million tonnes[6]. Although it is non-biodegradable
most of it is recyclable. The recycled products are even more environmentally harmful than
the first time manufactured ones. This is because every time plastic is recycled it is subject
to high intensity heat causing it to deteriorate and add to environmental pollution[2]. The
need of the moment is to find an effective way to deal with this non-biodegradable waste.
The Plastic Road is one such solution.
The environmental advantage of plastic roads arises from the fact that it uses plastics that
would otherwise be disposed through environmentally harmful means. One of the
acceptable methods of dealing with plastic waste all over the world is incineration.
Incineration, simply put is, the burning of plastics in the presence of oxygen. However often
incinerators used are not manufactured keeping in mind the recommended standards and
guidelines. As a result when we burn plastics, in an attempt to dispose them, highly toxic
0%
5%
10%
15%
20%
25%
30%
35%
40%
0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 3.5%
%Plastic used
Percentages for various tests against plastic used
Abrasion
Moisture absorption
Soundness
Impact value
Voids
%
obtained
for each
test
13. Varun Suriyanarayana
emissions are released. These include Carbon Monoxide, Chlorine, Hydrochloric Acid,
Dioxin, Furans, Amines, Nitrides, Styrene, Benzene, 1, 3- butadiene, CCl4, and Acetaldehyde.
These emissions cause air pollution[2] resulting in acid rain, death of various animals and
contribute to the greenhouse effect thereby magnifying global warming. Furthermore the
incineration requires energy and this energy inevitably ends up coming from fossil fuels
burnt elsewhere. Therefore, the impact of incineration, on the environment is twofold. The
burnt plastic harms the environment as do the fuels burnt to produce energy for the
burning of the plastics. To compound matters, the process of incineration produces an ash.
This contains toxic heavy metals like lead and cadmium. If not kept in strong airtight
containers, these may leach into surroundings[7]. It has also been suggested that
incineration can cause monsoon failure or drought[26]. The usage of plastic is particularly
significant because approximately 1 million carry bags are used to lay 1km of road. This
translates into 1.125 tonnes of plastic per km of single lane road[4]. Furthermore, the dry
process does not result in the burning of plastics- they are only heated[3]. Because the
plastics are not burnt 3 tonnes of carbon dioxide per km of road is not liberated into the
atmosphere[4]. The 2500 km of road that has been laid in India this way has saved over 2500
tonnes of plastic waste and this in turn has meant that 7500 tonnes less of CO2 has escaped
into the atmosphere. This in turn reduces the effect of global warming[3].
Another popular method is the disposal of the plastic waste into specifically built up landfills
however, landfills are not a problem free solution either. Plastics disposed in the landfills are
impermeable and this means that the indiscriminate disposal of plastic waste makes land
infertile. To make matters worse these plastics contain lead and cadmium pigments. These
pigments are additives that are usually found in LDPE, HDPE and PP. They are toxic in nature
and prone to leaching[2]. The chlorinated plastic waste in landfills tends to contaminate the
surrounding space with harmful chemical which can find their way into groundwater. The
water in turn harms all living organisms who consume it[8]. In case of other kinds of plastics
micro-organisms in the landfill speed up their biodegradation. The biodegrading plastics
release methane, a gas which is known to have an adverse effect on global warming[9].
For every 1km of plastic road constructed, 1.125 tonnes of plastic waste does not end up in
a landfill. This in turn will reduce the size/area of the landfills required for disposal of
municipal solid waste. The more the municipal solid waste, the larger the area that is
required for its disposal. Every time a new landfill is created a space is identified and cleared
of all vegetation and along with the vegetation the existing ecosystem is either disturbed or
destroyed.
Plastic waste that lies around or in garbage disposal bins can find its way into the stomachs
of animals and birds who source their food from such places. The toxins in the plastics once
inside the bodies of the animals and birds cause intense suffering and pain. They can even
cause death. Additionally they become a part of the food chain and indirectly affect even
those who have not actually consumed any plastic. Plastic roads can definitely reduce and
perhaps eventually eliminate this suffering.
14. Varun Suriyanarayana
Roads are made with Bitumen. Bitumen is a hydrocarbon derived from crude oil. Replacing a
percentage of Bitumen with plastic means reducing the amount of Bitumen required,
resulting in reduced net oil consumption and the amount of oil that extracted. This brings
down the negative effects of oil extraction and ensures oil reserves will last longer, thereby
giving us more time to figure out alternative ways to meet our fuel needs. Methane is a gas
that can be released by the Bitumen upon heating. Although the resultant greenhouse
effect methane has is lesser than that of CO2, this is because the concentration of CO2 in the
atmosphere is greater than the concentration of methane in the atmosphere. In fact, the
negative effects of one molecule of methane are significantly more than one molecule of
CO2.
The plastic roads, because they are less susceptible to damage and breaking down, provide
better mileage and decrease fuel consumption resulting in reduction of greenhouse gases
generated by the vehicles.
Economic advantage
The merits of the plastic road are not merely environmental. They have a considerable
financial impact as well. The cost of construction of roads decreases considerably with the
use of plastic. Since 10 %– 15% of Bitumen is replaced by plastic, the cost benefit is sizeable.
According to Dr. Vasudevan’s report, the construction of 10m2 of road costs nearly Rs. 4
lakhs. The integration of plastic reduces the cost by Rs. 25000. This translates to over 6%
savings on the construction of the road. There is no additional time required for the
construction of the road as compared to the Bitumen road. The equipment used is also the
same. The resulting road is superior to the Bitumen road. It requires far less maintenance
because the road is much more durable and can last for up to twice as long as normal roads
and is resistant to most factors that cause a road to break down. This means that less
material, labour and time is required to service the road thereby allowing for resources to
be diverted towards the expansion of infrastructure instead of maintaining the existing one.
[3]
In countries like India, a lot of goods and people are transported by road and the trucks and
buses used for this purpose contribute significantly to the economic growth of the country.
If the roads are better, vehicles do not experience undue stress resulting in premature wear
and tear which in turn reduces the cost of transportation. Better quality roads also translate
into better fuel efficiency.
This directly impacts the cost of transportation of the goods and their prices. Improved fuel
efficiency implies lower fuel consumption. This reduction in fuel consumption results in less
imports and hence savings for both the government and the people. Better quality roads
translates into less time spent on the road, reduced fatigue caused by driving and
commuting and resultant increased efficiency and productivity.
Plastic waste which was earlier considered worthless rubbish, created environmental
trouble and had to be disposed of at a cost suddenly becomes a valuable means of
generating revenue. Rag pickers and small entrepreneurs can segregate the waste, shred
the waste and sell it to the road construction industry in huge quantities. In order to utilise
15. Varun Suriyanarayana
plastic waste, it is required to be collected from various sources. The possibility of securing
an income from plastic waste collection prompts the uneducated and unemployed to
become rag pickers, waste plastic segregators or cleaners and seek employment in waste
plastic shredding houses.
In some countries, carbon credit can be sold. Since the road industry and plastic waste
disposal industry would now emit far less carbon, they could sell their extra carbon credits
to others thereby earning themselves a financial benefit. This in turn could be used to
benefit the community at large by being donated to charities or being used constructively
for infrastructural improvements. The carbon tax would also be lower
Dr. Vasudevan has even gone so far as to suggest that if this idea were to be implemented
on a national scale, India would need to import plastics from other countries. Instead of
importing, India could charge other countries for helping them with the disposal of their
plastic waste thereby creating another source of income.
Safety advantage
Plastic roads when compared with Bitumen roads have been proven to be more durable.
Susceptibility to cracks, abrasion, weathering and pot holes is considerably reduced. It has
an improved load bearing capacity and skid resistance. When compared to concrete roads
they have better skid resistance in wet conditions. Since no toxic emissions occur in the
process of road making, plastic waste is disposed in a safe and hazard free manner. All this
means is that there is less wear and tear of vehicles, reduced driver fatigue leading to lesser
accidents and improved safety.
CONCLUSION
The plastic road is worthy of serious consideration particularly for countries with a large
population because the volume of their plastic waste and the extent of their road
construction is bound to be far more than that of countries with less population. What is
important to note is that the implementation of this technology is totally devoid of any
complication and additional investment. The process is easy and does not require new
machinery, industrial involvement or infrastructural investment. The entire process can be
implemented at the site where the road is to be laid. Since 10-15% Bitumen is replaced by
plastic, Bitumen resources are saved and plastic waste is utilised in an environment friendly
manner. This process can be conducted using both the mini hot mix plant and the central
mix plant and if both are available both can be used to speed up the road construction. Both
60/70 and 80/90 grade Bitumen can be used. During the entire process, no toxic gases like
dioxin are released because dioxin requires chlorine which is not present in any of the
plastics used. Polyvinyl chloride cannot be used for this reason. Furthermore, fly ash, a
difficult to dispose residue from incineration, can be integrated into the mixture as an
additional binding agent. [5]
By adding plastic to roads the resultant road is transformed. Unlike normal roads which do
not survive in extreme conditions, plastic roads are far more resistant to extremes in heat,
16. Varun Suriyanarayana
cold and rain. They are stronger, more durable and require less maintenance. This road is a
viable alternative for places with bad road access e.g. hills. It can help to improve national
infrastructure and enable supply to and from those areas to be more efficient, thereby
resulting in an improved quality of life for those people who live in the hills and benefits the
economy in general. [27]
The benefit of a plastic road lies not so much in the fact that the Bitumen road becomes
more durable and stronger but in the fact that it appears to provide us with an effective
solution to a potentially deadly problem of plastic waste disposal, a problem that the world
faces. Additionally, it helps to save fuel and Bitumen both of which are obtained from a
rapidly depleting natural resource, the crude oil. For the moment it does seem like an ideal
option. However it would be prudent to keep in mind that the world uses 85 million tonnes
of Bitumen to make its roads, even if this were to decrease by 10-15%, we will run out of
Bitumen and indeed crude oil in the near future. [21]
In India plastic road technology is being implemented, increasingly. On a small scale, certain
parts of India like Jamshedpur have converted to 100% plastic roads and proudly claim to be
a plastic waste free town. The scope of this technology is enormous and its benefits,
numerous - nevertheless on a large scale, the plastic road is a relatively localised
phenomenon, and it is being implemented extensively, mainly, in some parts of South India.
If this technology’s full potential is to be realised it has to be implemented on a national and
eventually on a global scale. In order to do this, awareness has to be increased at every level
and there have to be significant efforts made by the department of road transport,
government, environmentalists as well as educational institutions.
Thus plastic roads are indeed the need of the hour for developing countries with large
population, where the demand for improved road network and the problem of plastic waste
disposal is never ending. This solution though good, can by no means be a permanent one.
The fact remains that, neither the problem of plastic waste disposal nor the need for roads
is going to vanish, but Bitumen eventually will. Alternative technology to build roads is
already available but what happens to the ever increasing amount of plastic waste? Perhaps
it is time to begin looking for ways to extend the application of this technology into other
directions. In fact, Dr. Vasudevan has already taken the first steps in this direction. He has
used plastic waste to create Plastone, an interlocking block made with gravel and plastic.
Plastone is strong enough to withstand 300 tonnes of weight, along with the ability to
prevent water penetration. This can be used as an alternative for laying roads as well as for
household and industrial flooring. [28] This means, the technology is versatile and it can,
possibly be applied extensively to modify existing materials used for other infrastructural
construction. This would ensure effective plastic waste disposal and give us materials with
better durability, greater environmental advantage, economic advantage and above all
safety.
17. Varun Suriyanarayana
BIBLIOGRAPHY
[1] http://www.ehow.com/info_8645892_stages-road-construction.html 14 June 2014
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[3] http://www.ajer.org/papers/v2(11)/A02110113.pdf 13 June 2014
[4] http://pmgsy.nic.in/WM_RR.pdf 12 June 2014
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[7] http://www.ecoants.com/wasteincineration.html 15 June 2014
[8] Aggarwal,Poonam; (et al.) Interactive Environmental Educatiaon Book VIII. Pitambar
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[9] Biello, David (June 5, 2011). "Are Biodegradeable Plastics Doing More Harm Than Good?".
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[10] Daniel D. Chiras (2004). Environmental Science: Creating a Sustainable Future. Jones &
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[11] Knight 2012
[12] Derraik 2002
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[14] http://en.wikipedia.org/wiki/Low-density_polyethylene 16 June 2014
[15] http://en.wikipedia.org/wiki/High-density_polyethylene 16 June 2014
[16] http://en.wikipedia.org/wiki/Polypropylene#Applications 16 June 2014
[17] Complete Chemistry for Cambridge IGCSE
[18] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1009718/pdf/brjindmed00129-0032.pdf
19 June 2014
[19]https://web.anl.gov/PCS/acsfuel/preprint%20archive/Files/07_1_CINCINNATI_01-
63_0055.pdf 19 June 2014
[20]http://iti.northwestern.edu/cement/monograph/Monograph2_3.html 19 June 2014
[21] http://www.eurobitume.eu/Bitumen/what-Bitumen 17 June 2014
[22] http://www.brighthubengineering.com/concrete-technology/45858-concrete-roads-vs-
asphalt-roads/ 17 June 2014
[23] http://pmgsy.nic.in/downloads/10janjun06_eng.pdf 17 June 2014
18. Varun Suriyanarayana
[24] http://www.thehindu.com/news/cities/Madurai/indian-roads-congress-clears-code-for-
plastic-road/article5477350.ece 3 July 2014
[25] http://www.thehindu.com/todays-paper/tp-national/tp-tamilnadu/another-big-leap-for-
green-chemistry/article2335034.ece 4 July 2014
[26]http://prezi.com/ld0d8x5slwjs/presentation-on-plastic-roads/ 4 July 2014
[27] http://www.nbmcw.com/articles/roads/18259-types-of-pavements-used-in-road-
construction.html 4 July 2014
[28] http://timesofindia.indiatimes.com/city/madurai/Professors-unique-product-can-solve-
plastic-menace/articleshow/20709066.cms 5 July 2014
[29]
http://stats.oecd.org/glossary/detail.asp?ID=4005 7 July 2014
[30]
http://indiainbusiness.nic.in/newdesign/index.php?param=industryservices_landing/367/2 7 July
2014
[31]http://www.triplenine.org/articles/roadbuilding.asp 7 July 2014
[32]http://saferenvironment.files.wordpress.com/2008/10/plastic_waste.jpg 7 July 2014
[33]http://upload.wikimedia.org/wikipedia/commons/7/76/TriagemDeLixo.jpg 7 July 2014
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[35]http://tce.edu/chemistry/step1b.jpg 7 July 2014
[36] http://tce.edu/chemistry/step3.jpg 8 July 2014
[37]http://www.featurepics.com/online/Stone-Aggregate-821672.aspx 7 July 2014
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infra-push/article4140548.ece 8 July 2014
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GjU/s1600/plastic-Bitumen+road.jpg 8 July 2014
[41] http://www.pavementinteractive.org/article/rutting/ 8 July 2014
[42] http://cthousegop.com/2014/03/ct-pothole-patrol/ 8 July 2014
[43] http://www.tehamacountypublicworks.ca.gov/Operations/images/ac_cracking.jpg 8 July
2014
[44] http://cnx.org/content/m42215/latest/Figure_14_02_04.jpg 8 July 2014
[45] http://rescoplastics.com/tough-problems-easy-solutions 8 July 2014
[46] http://theconstructor.org/building/building-material/determination-of-los-angeles-
abrasion-value/1361/ 14 July 2014
![Varun Suriyanarayana
PLASTIC ROADS – THE
WAY AHEAD
(A RESEARCH REPORT)
[49]
Varun Suriyanarayana Guided by Dr. Rajappan Vetrivel](https://image.slidesharecdn.com/suriyanrayanavarunplasticroads-thewayaheadaugust2014-140812110407-phpapp01/85/Suriyanrayana-varun-plastic-roads-the-way-ahead-august-2014-1-320.jpg)
