Plastic Roads

Plastic-waste in road construction i.e., Plastic roads. The present newly construction method highlights the developments in  using plastics waste to make plastic roads.The use and abuse of plastics vis-a-vis environmental protection  can go on, without yielding results until practical steps are initiated at the grassroots level by everyone who is in  a position to do something about it. The plastic wastes could be used in road construction and the field tests  withstood the stress and proved that plastic wastes used after proper processing as an additive would enhance the life of the roads and also solve environmental problems. Plastic is everywhere in today’?s lifestyle. It is used  for packaging, protecting, serving, and even disposing of all kinds of consumer goods. With the industrial revolution, mass production of goods started and plastic seemed to be a cheaper and effective raw material.  Today, every vital sector of the economy starting from agriculture to packaging, automobile, building construction, communication or infotech has been virtually revolutionised by the applications of plastics. Use of  this non-biodegradable (according to recent studies, plastics can stay unchanged for as long as 4500 years  on earth) product is growing rapidly and the problem is what to do with plastic-waste. Studies have linked the  improper disposal of plastic to problems as distant as breast cancer, reproductive problems in humans and  animals, genital abnormalities and even a decline in human sperm count and quality. If a ban is put on the use  of plastics on emotional grounds, the real cost would be much higher, the inconvenience much more, the  chances of damage or contamination much greater. The risks to the family health and safety would increase  and, above all the environmental burden would be manifold. Hence the question is not ‘?plastics vs no  plastics’? but it is more concerned with the judicious use and re-use of plastic-waste.

Not New.!

Plastic use in road construction is not new. It is already in use as PVC or HDPE pipe mat crossings built by cabling together PVC (polyvinyl chloride) or HDPE (high-density poly-ethylene) pipes to form plastic mats. The  plastic roads include transition mats to ease the passage of tyres up to and down from the crossing.Both  options help protect wetland haul roads from rutting by distributing the load across the surface. But the use of  plastic-waste has been a concern for scientists and engineers for a quite long time. Recent studies in this  direction have shown some hope in terms of using.

A Bangalore-based firm and a team of engineers have  developed a way of using plastic waste for road construction. An initial study was conducted in 1997 by the  team to test for strength and durability. Plastic roads mainly use plastic carry-bags, disposable cups thickness  up to 60micron (PE, PP and PS), Hard foams (PS) and any thickness (PET) bottles, Soft Foams (PE and  PP) any thickness. Laminated Plastics thickness up to 60 micron (Aluminum coated also) packing materials  used for biscuits, chocolates, etc., That are collected from garbage dumps as an important ingredient of the  construction material. When mixed with hot bitumen, plastics melt to form an oily coat over the aggregate and  the mixture is laid on the road surface like a normal tar road.

Basic Process

Waste plastic is ground and made into powder; 3 to 4 % plastic is mixed with the bitumen. Plastic increases the melting point of the bitumen and makes the road retain its flexibility during winters resulting in its long life. Use of shredded plastic waste acts as a strong “?binding agent”? for tar making the asphalt last long. By mixing  plastic with bitumen the ability of the bitumen to withstand high temperature increases. The plastic waste is  melted and mixed with bitumen in a particular ratio. Normally, blending takes place when temperature reaches 45.5C but when plastic is mixed, it remains stable even at 55C. The vigorous tests at the laboratory level  proved that the bituminous concrete mixes prepared using the treated bitumen binder fulfilled all the specified Marshall mix design criteria for surface course of road pavement. There was a substantial increase in Marshall Stability value of the BC mix, of the order of two to three times higher value in comparison with the untreated orordinary bitumen. Another important observation was that the bituminous mixes prepared using the treated binder could withstand adverse soaking conditions under water for longer duration.

Comparison

The durability of the roads laid out with shredded plastic waste is much more compared with roads with asphalt with the ordinary mix. Roads laid with plastic waste mix are found to be better than the conventional ones. The binding property of plastic makes the road last longer besides giving added strength to withstand more loads. While a normal 'highway quality' road lasts four to five years it is claimed that plastic-bitumen roads can last up to 10 years. Rainwater will not seep through because of the plastic in the tar. So, this technology will result in lesser road repairs. And as each km of road with an average width requires over two tonnes of polyblend, using plastic will help reduce non-biodegradable waste.

Expensive?

The cost of plastic road construction may be slightly higher compared to the conventional method. However, this should not deter the adoption of the technology as the  benefits are much higher than the cost. Plastic  roads would be a boon for countries like India’? Hot and extremely humid climate, where temperatures  frequently cross 50C and torrential rains create havoc, leaving most of the roads with big potholes. Already, a  kilometre-long test-track has been tested in Karnataka using this technology. The government is keen on  encouraging the setting up of small plants for mixing waste plastic and bitumen for road construction. It is hoped  that in near future we will have strong, durable and eco-friendly roads which will relieve the earth from all type of plastic-waste.

Plastics will increase the melting point of the bitumen. The use of the innovative technology not only  strengthened the road construction but also increased the road life as well as will help to improve the  environment and also creating a source of income. The plastic roads include transition mats to ease the  passage of tyres up to and down from the crossing. Both option of making roads was to protect wetland haul  roads from cracks by distributing the load across the surface. 

A stretch of 800 metre bus route of Valluvar Kottam High Road from Unit Office 21 Junction to Dr.MGR Salai  junction would have 13,700 square metre of plastic road in chennai. A 1,250-metre stretch of Nelson  Manickam Road would have 22,500 square metre of plastic road. The civic body would complete re-laying of  121 plastic roads on 80-km-long bus routes at a cost of Rs.51.7 crore. Shredded plastic waste would form at  least 8 per cent of the weight of the binder used for re-laying. Initially, the civic body planned to use plastic for  re-laying of the top layer of 40 mm in the roads. The 75 to 50 mm macadam layer beneath the top layer of 40  mm is also likely to have plastic content in areas where damage to road is high. The Corporation has put in  place bins for collection of plastic waste in every ward office. The civic body is procuring plastic for road re- laying, as it is yet to get enough plastic waste from residents. Patch work on Anna Nagar West School Road,  Perambur High Road, Greams Road and Taluk Office Road also ready for began. Work on 292 km of interior roads started at a cost of Rs.59.5 crore.

World's Longest and Sturdiest Recycled Bridge

Stretching out across the peaceful waters of the River Tweed in Peeblesshire, Scotland, the Dawyck Estate  river crossing is an unlikely record breaker. Measuring 30 meters in length and made entirely out of waste  plastic products, the newly completed structure is the world's longest and sturdiest recycled bridge. Utilizing a super-strength composite plastic material -- engineered by researchers at Rutgers University from  items as common as plastic bottles and household plastic waste -- the bridge caters for pedestrians, cars and  heavy goods vehicles. The river span is one of five such structures now in existence, although all others are  smaller and based in the U.S., and can support weights of up to 44 tons. According to Vertech Composites,  the British company behind the project, the bridge is a prototype that has the potential to meet future road and  bridge requirements in an eco-friendly manner.