Technologies can help manage waste as well as make hardy roads
is there a way to deal with the incessant solid waste of India? The answer could be yes, if two technologies are given impetus. Both involve the use of waste material like plastic bags to make roads.
The first technology, developed by Bangalore-based K K Plastic Waste Management Limited, entails using plastic waste along with bitumen -- the conventionally used ingredient to make roads. There are two ways of doing so: dry mixing and wet mixing. Dry mixing implies that plastic waste (mainly polythene bags) is shredded and then mixed with bitumen. In wet mixing, plastic is reduced to a powdered form and then mixed in bitumen. "Our study shows that in the powdered form, plastic is able to bind better with bitumen," says Sunil Bose, deputy director of the New Delhi-based Central Road Research Institute (crri), which has approved the technology for countrywide use.
The technology can help overcome the drawbacks of conventional system -- roads containing plastic do not easily develop cracks when water seeps in. Plastic also resists the softening of bitumen at high temperature and friction.
The only downside of the technology is the capital cost -- for any given stretch of road, cost of using dry mixing will be 15-20 per cent higher than that of conventional technology; cost of wet mixing will be about 30 per cent more. "But the expense can be recovered in the long-run, as these roads require less maintenance. Moreover, using plastic means solving a mammoth environmental problem -- on an average, two tonnes of polyblend (plastic bags) is required for each kilometre of road," asserts Bose.
The process of using fujibeton to make roads is simple. Surface soil is first loosened with the help of a cultivator. Then a mixture of fujibeton, cement and any waste is spread on the soil. Subsequently, all the ingredients are mixed and water is sprinkled. Thereafter, the materials and soil are again mixed. Finally, a thin layer of concrete is laid. Using the process, a one-kilometre-long and seven-metres-wide road can be build within three days.
"The biggest advantage of using fujibeton is that the road is free of aggregates (rocks). This means that there would be no mining of rocks to make the road base," says Shiban Raina, director-general of ncb. Conventionally, coarse aggregates are used for the construction of roadbeds. But in case of the fujibeton technology, the hardened soil itself becomes the base. "Moreover, no money is spent on purchasing and procuring the rocks from long-distance. This also reduces the cost of operation. Construction time is also very less," states Satish Sharma, group manager, construction development and research, ncb. Use of the technique also means that even the remotest parts of the country could be connected to the cities. According to Shiban, the technology can even help provide employment to many, as no skilled labour is required for the road construction process.
In Japan, the technology has been used on a wide-scale. But why is the Indian government not adopting it? "We keep informing the officials. But when it comes to implementation, the government gets changed and the situation comes back to square one," asserts Raina. With any luck, the present Union government would ensure the effective implementation of both the technologies.
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