Technology of making Plastic Roads
The serious use of plastic for roads construction in India started in 2015 when Union government issued guidelines on plastic use with hot mixes for bitumen roads around urban areas. Over the years, these roads constructed using waste plastic, popularly known as Plastic Roads, are found to perform better compared to those constructed with conventional bitumen. As a result Plastic Roads have been increasing seen as one possible solution of Plastic Waste Management.
Waste Plastic that can be used for making roads:
The plastic waste items that can be used for road construction are various items like plastic carrybags, plastic cups, plastic packaging for potato chips, biscuits, chocolates, etc.
As per the circular guidelines issued by Ministry of Rural Development, GoI, for the use of Plastic Waste in Rural Roads Construction (1). The following types of waste plastic can be used in the construction of rural roads:
- Films ( Carry Bags, Cups) thickness up to 60micron (PE, PP and PS)
- Hard foams (PS) any thickness
- Soft Foams (PE and PP) any thickness.
- Laminated Plastics thickness up to 60 micron (Aluminum coated also) packing materials used for biscuits, chocolates, etc.,
Poly Vinyl Chloride (PVC) sheets or Flux sheets should not be used in any case
Basic Process of using Plastics for Roads:
Once all the plastic waste is shredded (a technique where all the dust particles are eliminated, and plastic items are shredded into fine pieces) these are heated at 165°c. Next, the shredded pieces are added to bitumen mix, which is also heated at 160°c. The final mix is used for constructing roads. Steps:
- 1) Waste plastic is first shredded
- 2) The plastic is then mixed with hot gravel
- 3) The mix is added to molten asphalt
- 4) Road is paved using the regular process
Salient feature of the process.
- Easy process without any new machinery
- In-Situ process
- Simple process without any industry involvement
- Use of lesser percentage of bitumen and thus savings on bitumen resource
- Use 60/70 and 80/100 bitumen is possible
- Both Mini Hot Mix Plant and Central Mixing Plant can be used
- Only aggregate is polymer coated and bitumen is not modified
- Use of plastics waste for a safe and eco-friendly process.
- No evolution of any toxic gases like dioxin
Ratio of use
One tonne of plastic waste is used with nine tonnes of bitumen to lay a kilometre of road. As per the circular guidelines issued by Ministry of Rural Development, GoI – Amount of plastic to be added is @8% of bitumen. For example if the bitumen quantity per minute is 10Kg, the plastic need to be added is 0.8 Kg. i.e. (A bucket can be used which can hold 0.8 Kg at a time) – Ref.