Civil Insight: A Technical Magazine Volume 2 | Page 44

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STUDENTS’ SECTION
CIVIL INSIGHT 2018
A CONCEPT OF PLASTIC ROAD
Abstract
The use and production of plastic is increasing
exponentially. Plastic wastes can be used as a coating over
aggregate and this coated stone can be used for road
construction with higher strength, durability and cost
effectiveness. The use of this concept will help use plastic
wastes effectively.
Bikash Sudhakar
Student
BE in Civil Engineering
(4 th Year)
Keywords: plastic road; bitumen
INTRODUCTION
The use and production of plastic is increasing exponentially due to rapid population growth, increasing
urbanization and changing life style. Plastic wastes, consisting of carry bags, cups and other utilized plastic can
be used as a coating over aggregate and this coated stone can be used for road construction. The mix polymer
coated aggregate and tyre-modifi ed bitumen have shown higher strength, durability and cost effectiveness.
Disposal of non-biodegradable waste is a global problem today and one of the major concerns is plastic waste.
About 400 million tons of plastics are produced per year globally and around 8300 million metric tons of
plastics have been produced to date. Only 18 percent of plastic is recycled and 12 percent is incinerated. For
plastic packaging (water bottles, chip bags, supermarket packaging, etc.) the recycling rate is just 14 percent.
Studies have shown that the global plastic production will have increased by 1800 million tons per year by
2050. These plastic wastes can be utilized in highway construction that can reduce pollution and disposal
problems.
Conventional bitumenous roads have lower load bearing capacities and have lower working temperature
range. So, they may develop cracks in cold climate and bleed during hot climate. Study shows that the use
of plastic modifi ed bitumen has enhanced the performance of road in many ways. Plastic road is a modifi ed
version of the conventional road made by adding bitumen to plastic coated gravels. Polymer and plastic
modifi ed bitumen are obtained with the incorporation of selected thermoplastics and shredded plastic from
discarded waste, natural plastic or any other suitable elastomers in bitumen.
METHODS
Processes for introducing plastics into bituminous mixes are as follows:
1. Wet Process: The shredded plastic waste of sizes 2 to 4mm are blended with hot bitumen at 180°C.
After proper stirring with mechanical stirrer and proper cooling upto 130°C to 150°C, it is mixed with
aggregates, known as waste plastic bitumen mix and is used for road laying attemperature of 110°C to
130°C.
2. Dry Process: Plastic wastes (excluding PVC waste) are collected, cleaned, dried and cut into size of 1.18
to 4.36 mm using shredding machine. The shredded plastic waste is then added to a heated aggregate
mix of 165°C. The plastic-coated hot aggregate is then mixed with hot bitumen at 150°C to 165°C and is
used for road construction at a temperature of 110°C to 120°C.
ADVANTAGES
1. Researchers have found that non-biodegradable waste like plastics can remain on earth for 4500 years
without degradation. Plastic road is one of the best solutions for solid waste management. One-ton plastic
bags can be incorporated in one-kilometer road.