Waste plastic for road construction

1. Managing waste plastic by
Utilization in Bituminous Road
Construction
Rajib Chattaraj
Astt. Chief Engineer, NH, PWD
Govt. of West Bengal

2. Outline of the presentation
• Introduction
• Problems Relating to Plastic Waste
• Sustainable Plastic Waste Management
Solutions
• Utilization of waste plastic in bituminous road
construction
• Indian Scenario of Plastic road construction
• Case study undertaken with North Bengal
Variety aggregates
• Conclusion
• Challenges ahead

3. Introduction
• Plastic is a synthetic polymer derived from petro-
fossil feedstock and made-up of long chain
hydrocarbons with additives, a non-biodegradable
material, used in almost every aspect of our life and
become an essential part of our society.
• Because of its durability, plastics accumulate and
remain persistent in the environment for around
4500 years .
• Management of plastics found in municipal solid
waste (MSW) is very critical sector because of its
non-biodegradability, and direct harmful effect to
flora, fauna and environment.

4. Environmental issues on disposal of Plastic Waste
• Indiscriminate dumping of plastic waste on land makes the land
infertile.
• Burning of plastics generates toxic emissions such as Carbon
Monoxide, Chlorine, Hydrochloric Acid, Dioxin, Furans, Amines,
Nitrides, Styrene, Benzene, 1, 3-Butadiene, CCl4, and
Acetaldehyde.
• Sub-standard plastic carry bags, packaging films (<40µ) etc. pose
problem in collection and recycling.
• Littered plastics give unaesthetic look in the city, choke the drain
and may cause flood during monsoon .
• Garbage mixed with plastics interferes in waste processing
facilities and also cause problems in landfill operations.
• Millions of mammals, birds, reptiles, and fish are reported to be
killed every year by the ingestion of plastic bags. Mostly plastics
affect marine wildlife either by entangling creatures or by being
eaten.

5. Some statistics and facts about Plastic Wastes

9. Some pictures world wide which speak for itself
River Yamuna near the historic Taj Mahal in Agra, India, on May 19, 2018

10. Solid waste including Plastic waste on Mt. Everest

11. Kathirana, on the outskirts of Sri Lanka's capital, Colombo

12. Kuta Beach in Bali on February 12, 2017

13. Coast of Manila Bay during the annual International Coastal Cleanup
Day in Paranaque city, Philippines, on September 16, 2017

14. Juhu beach in Mumbai, India, on June 2, 2018

15. Garbage dump near Khabarovsk, Russia, on May, 27, 2018

16. Village of Digampathana in north-central Sri Lanka, on May 11, 2018

17. A black-footed albatross chick with plastics in its stomach lies dead
on Midway Atoll in the Northwestern Hawaiian Islands on November
2, 2014

18. Indian stall owners sit alongside a dry canal filled with plastic bags
and garbage in Jalandhar on May 10, 2018

19. Bangladeshi people walk across a bridge on the river Buriganga, choked
with plastic and other waste, in Dhaka, Bangladesh, on June 4, 2018

20. Problems- the Indian Scenario
• The average per capita
consumption of plastic in India is
about 11 kg, which is
considerably low as compared to
the global average of 28 kg.
• As per the Central Pollution
Control Board (CPCB) reports,
plastic contributes to 8% of the
total solid waste, with Delhi
producing the maximum
quantity followed by Chennai,
Kolkata, Mumbai, and
Bengaluru.
• The report also says that 60% of
the total plastic waste is being
recycled.

21. Top five cities in India generating maximum plastic
waste

23. A comparative picture of municipal solid waste amongst the states of India

24. Scenario in West Bengal
• As per the study of Central Pollution Control Board, the Plastic
waste generation in West Bengal is 2,00,750 tons/annum.

25. Sustainable Plastic Waste Management Solutions
• One of the sustainable alternatives that could
be considered to deal with plastic waste is to
develop bio-based and biodegradable plastic
which utilize starch, cellulose, and poly lactic
acid as raw materials for short-term use
products. However, these are more
expensive and are presently at a laboratory
scale, which needs to be upscaled.

26. Another potential use of plastic is to generate fuel
from waste plastics. The current energy
requirements are predominantly met using fossil
fuels. Converting waste plastics to fuel is beneficial
as it not only allows for waste plastic to be disposed
of but also presents the opportunity of developing an
alternative to fossil fuel. However, this is still at the
research stage. Studies reveal that presently, the
‘methane number’ of pyrolysis gases is below 65
which is less than the minimum requirement as per
the standard for the EU and USA.
Sustainable Plastic Waste Management Solutions

27. Sustainable Plastic Waste Management Solutions
• Non-recyclable plastic waste finds its
application in the co-processing of plastic
waste in cement kilns. This refers to the use
of wastes in industrial processes from which
the energy and material form is recovered.

28. Sustainable Plastic Waste Management Solutions
• Recycling of plastics is considered as one of the
most viable and technically feasible option to tackle
plastic waste. The approach utilizes several
technologies to produce a second supply chain of
raw materials. Recovery of secondary raw materials
through recycling is given the highest priority after
reuse, according to the waste hierarchy.
• Recycling requires participation from the public and,
therefore, needs citizens to perform separation of
waste materials at the source.

29. Separation of waste collection at source

30. Swachh Bharat My Clean India

31. Sustainable Plastic Waste Management Solutions
• Plastic waste can also be integrated with
bitumen for construction of roads. Both
plastic and bitumen having petrochemical
origin, they are compatible for mixing with
each other. The process of laying roads by
utilizing this technique has been well
established for the advantages it offers.

32. Type of Plastics as per BIS code
Out of the above varieties, the last type is not recyclable

33. Utilization of Plastic Waste in Road Construction
• Collection and segregation of plastic waste (Except
chlorinated/brominated plastic waste)
• Transportation and storage of plastic waste
• Cleaning and sun drying of plastic waste
• Shredding of plastic waste (2 to 4 MM size)
• Heating of stone aggregate (160 C -170 C)
• Adding of shredded plastic waste (5 to 10% by
weight of bitumen for 30 to 40 seconds)
• Coated aggregate is mixed with hot bitumen (Temp
155 C to 163 C)
• The mix-plastic aggregate bitumen mix (130-140 C)
The mix can be used for road laying

34. Utilization of Plastic Waste in Road Construction
Schematic flow diagram of plastic coated bitumen road construction

35. • Laboratory performance studies were
carried out on the bituminous mixtures
• Laboratory studies proved that waste plastic
enhances the property of the bituminous
mixture
• Utilization of waste plastic as bituminous
mixture modifier can be one of the solutions
for safe and useful disposal
Laboratory studies (dry process)

36. Physical properties of shredded waste plastic
Sl. No Description Range
1 Specific Gravity 0.98- 1.03
2 Melting Temperature 75 - 138 °C
3 Weight Loss (6 %) 200 - 400 °C
Waste Plastic used in shredded form

39. ▪ Varying percentages of waste plastic by
weight of bitumen was added into the
heated aggregates
▪ Cylindrical specimens with varying waste
plastic content was tested for bulk density
and Marshall stability
▪ Maximum value of Marshall stability was
considered as criteria for optimum waste
plastic content
Optimum waste plastic content
140
0
150
0
160
0
170
0
180
0
0 2 4 6 8 1
0
1
2
Waste Plastic
(%)
Stability
(Kg)
2.3
3
2.3
4
2.3
5
2.3
6
2.3
7
2.3
8
Bulk
Density
(gm/cc)
Stability
(Bulk
Density)
8% dose of waste plastic by weight of bitumen has been found to be optimum

40. Comparison of WP and VG30 bituminous
mixtures
Binder V/s
Stability
120
0
130
0
140
0
150
0
160
0
170
0
4.
5
5 5.
5
6
Binder,
%
Stability,
kg
Binder V/s Bulk
Density
2.31
0
2.33
0
2.35
0
2.37
0
2.39
0
4.
5
5 5.
5
6
Binder,
%
Bulk
Density,
gm/cc
Binder V/s
Flow
2.
5
3.
0
3.
5
4.
0
4.
5
5.
0
4.
5
5 5.
5
6
Binder,
%
Flow,mm
Binder V/s Air
Voids
2.0
0
3.0
0
4.0
0
5.0
0
6.0
0
7.0
0
4.
5
5 5.
5
6
Binder,
%
Air
Voids,%
Binder V/s
VFB
50.
0
55.
0
60.
0
65.
0
70.
0
75.
0
80.
0
85.
0
4.
5
5 5.
5
6
Binder,
%
VFB,%
VG30 Bitumen
+ Waste Plastic
VG 30 Bitumen

41. Volumetric properties of bituminous
mixtures
Properties Modified mixture
with 8 % WP
(by wt of bitumen)
Conventional
mixture with
VG30 bitumen
Marshall Stability (kg) 1700 1450
Bulk Density (gm/cc) 2.350 2.374
Air Voids (%) 4.4 3.5
VFB (%) 73 75
Flow (mm) 4 4
VMA (%) 16.5 15.6
Retained Stability (%) 98 88

42. Performance studies of the bituminous
mixtures
Tests VG30 VG30+WP
Indirect Tensile
Strength (MPa)
0.68 0.90
Fatigue
(no. of cycles)
8650 17554
Rutting after 20,000
repititons (mm)
8.0 6.0

43. Rut depth performance studies of Conventional
mix and WP modified mix

46. ▪ The optimum quantity of waste plastic was 8 %
by weight of bitumen (0.4 % by weight of the
mixture)
▪ Retained stability of the mix with waste plastic
was up to 98 %
▪ No traces of stripping even after 20,000 cycles
of rutting
▪ It can be inferred that addition of waste plastic
improves the water resistance property of the
bituminous mixture
Concluding remarks on dry process

48. Properties of modified bitumen
(wet process)

49. Comparison of BC mixture properties
at Optimum Binder Content
Binder OBC
%
BD
g/cm3
Stab
kg
Flow
mm
Vv
%
VFB
%
R.
Stab
%
60/70 5.4 2.359 1193 3.7 4.3 74.9 82
CRMB-60 5.8 2.354 1371 3.5 4.2 74.9 86
Elvaloy 5.5 2.362 1187 3.5 4.2 74.2 90
WP 5.7 2.349 1278 2.8 4.8 71.7 90

50. Rutting potential of bituminous mixtures
with different binders

51. Indian Scenario
• Prof.Rajagopalan Vasudevan, A 73-year-old retired chemistry
professor from the Thiagarajar Engineering College in
Madurai, recipients of the Padma Shri, is known as the
“Plastic Man of India” for devising an innovative way of
disposing of plastic waste – by using it to build roads.
• In 2002, Vasudevan came up with the idea of spraying dry,
shredded plastic waste, made up of pieces as small as 2 mm
in size, over gravel or bitumen heated to 170 degrees
Celsius. The plastic melted and coated the stones with a thin
film. The plastic-coated stones were then added to molten
tar. Since both plastic and bitumen are petroleum products,
they bind well. Vasudevan first tried out this technique to
pave a road on the college campus. It yielded twin benefits:
it reused plastic waste and built durable roads.

52. Prof.Rajagopalan Vasudevan

54. Other works
• Mahabir Panda and Mayajit Mazumdar, IIT
Kharagpur, 1997
• Priya Narayan, 2001
• V S Punith and Prof. A. Veeraraghaban,2003/2007
• Sunil Bose and Sridhar Raju, 2004
• S S Verma, 2008

55. IRC guideline on Waste Plastic
modified bituminous mix
IRC:
SP-98-
2013
The guideline
also specifies
about dry
process only.

56. Investigation for utilization of waste plastic in using North
Bengal variety aggregates in bituminous layer.
• Primarily North Bengal variety aggregate has been
considered for this study because these aggregates
have problem in adhering to bitumen specially
under action of rain water.
• Rain fall in North Bengal is also quite high.
• Waste Plastic modified bituminous mix enhances
mix properties which can resist higher rain fall.
• Thus, if the findings of the study can satisfy the
requirements of sustaining bituminous mixes with
North Bengal variety stones with high rain fall, a lot
of govt money can be saved .

57. Investigation for utilization of waste plastic in using
North Bengal variety aggregates in bituminous layer.
• Testing of physical properties of aggregates
from different sources in North Bengal as per
MoRT&H guidelines.
• Variety of Bitumen used VG-30 and VG-40
and testing their properties along with WP
modification.
• Waste Plastic : How it is collected?
• Plastic bags bought ( for laboratory study)
• Collected from waste plastic pickers.

58. Investigation for utilization of waste plastic in using North
Bengal variety aggregates in bituminous layer.
• Collected from Municipal Solid Waste
• Properties of Plastic : -
• (a)Thickness (b) Colour (c) Specific gravity (d)
Melting point from all sources
• Process of mixing : -
• (a) Dry process - waste plastic mixed with
heated aggregate first then bitumen is added
(b) Wet process – waste plastic mixed with
hot bitumen first and then it is mixed with
aggregates.

59. Investigation for utilization of waste plastic in using North
Bengal variety aggregates in bituminous layer.
• Preparation of Marshall Moulds and
determine optimum bitumen content by
both dry & process. Compare with
conventional process – advantages and
disadvantages.
• Indirect tensile test.
• Retained stability test
• Stripping value improvement study.

60. Investigation for utilization of waste plastic in using North
Bengal variety aggregates in bituminous layer.
• Study of Improvement in property by use of
waste plastic in high rainfall area by doing
moisture sensitivity test.
• Further technical studies.
• Economical analysis of using the method.

61. North Bengal Variety Aggregate Mixing shraded plastic with bitumen
Some photographs of the Laboratory testing

62. USE OF NORTH BENGAL VARIETY AGGREGATE IN
BITUMINOUS WORKS WITH WASTE PLASTICS
Conducted experiments mainly with two methods
WET PROCESS:
Mixing shredded waste plastic to bituminous mix in
percentage of 3%, 6%, 9% & 12% by weight of bitumen.
DRY PROCESS:
Mixing shredded waste plastics to aggregate initially in
percentage of 3%, 6%, 9% & 12% by weight of bitumen.
Conducted physical properties for bituminous mix,
aggregates with and without plastics.(wet process and dry
process)
Shredding of Plastic: size in between 2.36mm-600 micron

63. Results of the study with different percentage of waste
plastic of both dry and wet process

64. Results of the study with different percentage
of waste plastic of both dry and wet process on
DBM Mix

65. Conclusion
• Waste Plastic modified bituminous mix performs better
in respect of stability and retained strength under action
of water.
• It also gives better fatigue and rut resistance.
• Dry process of mixing gives better results.
• 8% of waste plastic by weight of bitumen is the
optimum dose in dense graded mixes to obtain best
result.
• More than 8% dose in dense graded mix may cause low
temperature cracking.
• For open graded mix like Premixed carpet, more than
8% dose may work for low volume trafficked road.

66. Conclusion
• The claim of reduction of the consumption of
bitumen may work in open graded mix but for
dense graded mixes the claim of reduction of
bitumen has not been established.
• Economy may be obtained by good engineering
practice through long term durability and improved
performance.
• Huge benefit is obtained by disposal of waste
plastic.
• In West Bengal, if used with North Bengal variety
stones, can have the prospects in using bituminous
work. In other places, this technology can also be
used.

67. Challenges ahead
• The main challenge is to arrange waste plastic in
sufficient quantity to be used in road construction.
• Segregation of the waste plastic at source is the
best solution but this practice is grossly absent in
our country.
• In the present scenario, separation of the blendable
waste plastic out of the total solid waste is also a big
challenge.
• Suitable mechanical arrangement in drum mix plant
and batch mix plant to charge very light weight
shredded plastic waste with the hot aggregate (dry
process) is also needed for proper implementation
of this technology.

68. Thank you
Acknowledgement: Dr. Sridhar Raju, Er.
Deepak Sigh, Er. P. Arun Kumar
Jamshedpur