Plastic Roads: Use of Waste Plastic in Construction of Roads

ABSTRACT

The global plastic production is increasing rapidly with rise in population and changes in life style. This makes the disposal of plastic is becoming complicated because of the non-biodegradable property. So, it is better to recycle than disposal. One of the trends in recycling of plastic is use in construction of roads. This type of recycling can also help in protecting the environment from the greenhouse gases that are exposed to atmosphere while disposal. The waste plastic in form of bottles, cups, caps, etc are made in form of powder or blended with crusher and coated over the aggregate and bitumen mixture by heating process for roads construction. This polymer coated aggregate and bitumen mixture shows high strength, better binding property, stability, and increase in wear resistance, better durability and tear of roads. This makes the recycle of plastic in an efficient manner.

1.      INTRODUCTION

            Today every sector around the world from agriculture to electrical, packing, automobile, building construction, communication sectors are widely using plastic. The usage was started after the industrial revolution and its large-scale production seemed to be cheap. Plastic is light in weight, moisture resistant, flexible and very inexpensive. These qualities increase our propensity towards plastic and hence making its use very common. It has revolutionized all spheres of life. But this plastic ultimately becomes a waste. It is a common site both in urban and rural areas to see plastic wastes littering the roads. It forms the major portion of the total municipal solid wastes (MSW). Generally, plastic is a non-biodegradable and many research found that plastic take around 4500 years to degrade. Several studies proven that the disposal of plastic causes many health problems and also reduces the fertility of soil. The plastic production over the world has crossed 400 million tons and the recycling of plastic is only 10%. Its improper disposal can cause serious health hazards in humans.


Fig 1: Increase in consumption of plastic year by year

            It is estimated that approximately 10 thousand tons per day (TPD) of plastics waste is generated i.e., 9% of 1.20 lacs TPD of MSW in India. The plastic waste constitutes two major categories of plastics; (i) Thermoplastics and (ii) Thermoset plastics. Thermoplastics, constitutes 80% and thermoset constitutes approximately 20% of total post-consumer plastics waste generated in India. The Thermoplastics are recyclable plastics which include; Polyethylene Terephthalate (PET), Low Density Poly Ethylene (LDPE), Poly Vinyl Chloride (PVC), High Density Poly Ethylene (HDPE), Polypropylene (PP), Polystyrene (PS) etc. However, thermoset plastics contains alkyl, epoxy, ester, melamine formaldehyde, phenolic formaldehyde, silicon, urea formaldehyde, polyurethane, metalized and multilayer plastics etc. The use of plastic materials such as carry bags, cups, etc. is constantly increasing. Nearly 50 to 60% of the total plastics are consumed for packing.