Jute, coir and waste material are set to make rural roads economic and eco-friendly
The road ahead
Narrow, kutcha, dusty, patchy and potholed. These are the words usually used to describe rural roads of India. But these roads may soon get a makeover and set a precedent in the way roads are being made in India.
In January this year, the Indian Roads Congress (IRC) released the Rural Road Specification Code, 2014, detailing how to use locally available material such as jute, coir and waste such as fly ash, plastic rubbish, paper mill sludge and construction and demolition debris in laying rural roads. IRC is a subsidiary body of the Union Ministry of Road Transport and Highways that sets design and material specifications for roads and bridges.
The need for such a code stems from the fact that rural roads are typically paved with bitumen or concrete. But underneath that smooth, black strip lies a potential economic and environment disaster.
For each kilometre of traditionally constructed road, tonnes of crushed stone, gravel and sand, together called aggregates, concrete and bitumen are needed, let alone the diesel required for powering the construction equipment. This is an expensive affair, particularly for India which needs to construct more than 0.2 million kilometres of rural roads and maintain another 0.3 million km to meet its vision for providing a road to each habitation by 2025.
“Rural roads help farmers transport agricultural produce to local markets and provide easy access to educational, healthcare and financial institutions. They are crucial in strengthening local economy and improving the quality of life of those who live in villages,” says Rajesh Bhushan, joint secretary of the Department of Rural Connectivity of the Union Ministry of Rural Development (MoRD). Though state governments are responsible for laying rural roads, their abysmal performance prompted the Centre to launch the Pradhan Mantri Gram Sadak Yojana (PMGSY) in 2000 for setting up the network. MoRD implements the programme as part of its initiative to alleviate rural poverty.
MoRD currently requires 1.2 million tonnes of bitumen a year and 37 million cubic metres (mcm) of aggregates a year for laying rural roads. This is done at an investment of Rs 20,000 crore to Rs 25,000 crore a year, according to an estimate by International Labour Organization (ILO). Over the next 12 years, MoRD’s requirement of bitumen would increase to 2.15 million tonnes a year and that of aggregates to 47 mcm a year.
Cost would skyrocket accordingly (see ‘India’s rural road challenge’).
“The consumption of aggregates across the country, which is 160 mcm by the reckoning of ILO, is enough to construct a single lane road along the equator,” says L R Kadiyali, an engineer who heads L R Kadiyali and Associates, a consultation firm in Delhi. “One can build a four-lane road along the equator using the 450 mcm of aggregates projected for use in 2030,” he says.
Use of aggregates and bitumen in such large quantities can do irreparable damage to the environment, says Mukesh Gupta, aggregate expert with ILO’s Decent Work Team for South Asia. Both bitumen and aggregates are non-renewable minerals. Worse, mining of sand, gravel and crushed stone remains largely unchecked. They are the most mined minerals in the country.
MoRD has been deliberating these matters since PMGSY was launched. “Initially, we had planned to reduce thickness of roads as per the population of habitations to save on raw materials,” says I K Pateria, director (technical) of National Rural Road Development Agency (NRRDA), which offers technical expertise to the government for constructing rural roads. Pateria explains that people in small villages mostly rely on two-wheelers and bullock carts. Roads connecting these villages need not be as thick as highways or district roads that are frequented by heavy vehicles and pedestrian traffic. Likewise, for drainage of canals, NRRDA recommended using hume pipes (a cemented pipe) instead of constructing costly culverts. But this was not enough.
Most roads paved with bitumen start eroding within a couple of years. According to ILO, every year 50,000 km of roads in India, worth Rs 20,000 crore, get eroded because of poor maintenance. This is the amount India invests every year in laying rural roads. Towards 2005, MoRD approached IRC and the Central Road Research Institute (CRRI), a premier national laboratory in Delhi, for innovative technologies that can make rural roads economical and durable. Since 2012, under the guidance of the institute, NRRDA has constructed nearly 1,500 km of roads in nine states using cost-effective and environment-friendly technologies and materials on an experimental basis (see ‘Tried and tested’). States such as Tamil Nadu implemented technologies innovated by independent scientists. IRC’s Rural Road Specification Code of 2014 is based on the performance of these roads.
Down To Earth analyses some of the technologies to find out how economical and environment-friendly they are.
Spread jute and coir, make roads stronger
10% cheaper than conventional roads; lasts 6-7 years
Every soil has a different capacity to withstand the load of vehicular and pedestrian traffic. Engineers use different technologies to reinforce soil’s load-bearing capacity. Typically, engineers strip the topsoil, pave the track with layers of aggregate as per traffic load, and seal it with bitumen. But all roads need not have high load-bearing capacity. In rural roads a thin layer of aggregates covered with geotextiles—woven fabrics, such as jute and coir mats, that are used to strengthen the soil—serve just right.
Jute was first used on a trial basis while laying the Kingsway bypass at Dundee, Scotland, in 1920. In 1934, jute was reportedly used to make the Strand Road in Kolkata. “But the trials were not followed up and the potential of jute in road construction remained unexplored for long,” says P K Choudhary, project coordinator of Indian Jute Industries’ Research Association (IJIRA). The initial successful experiments of the technology were done in 1996-97 in South 24 Parganas of West Bengal and in Kakinanda town of Andhra Pradesh. Since then, 62 jute roads have been built across the country.
Jute geotextile serves another purpose of PMGSY: strengthening rural economy. According to the National Jute Board, more than 4.5 million people depend on the jute sector for a living. “Larger use of jute geotextile would help retain this large work force,” says Tapobrata Sanyal, chief consultant of the board. Citing several studies, Sanyal says at least 100 million sq km of jute geotextiles are needed for paving the country’s rural roads. “There are jute mills in West Bengal, Assam, Bihar, Tripura and Andhra Pradesh. All of eastern and north-eastern states, Madhya Pradesh and a good part of the southern states can easily procure jute geotextile from these mills for paving their rural roads,” Sanyal adds.
Rural roads in coastal areas can be built using another geotextile—coir mats. So far, NRRDA has laid 460 km of roads using coir in Assam, Odisha, Andhra Pradesh, Kerala, Karnataka, Tamil Nadu, Jharkhand, Chhattisgarh and Madhya Pradesh as part of its trial, says U S Sarma, adviser at Central Coir Research Institute under the Ministry of Micro, Small and Medium Enterprises. Sarma says use of coir in paving rural roads can generate 10,000 employment opportunities in cottage industries.
Geotextiles can reduce the requirement of aggregate by up to 15 per cent, says U K Guru Vittal, senior scientist at Geotechnical Division of CRRI. Consumption of bitumen also reduces. As an added advantage, the lifespan of roads increases by three to four years. This cuts down the maintenance cost. Guru Vittal says geotextiles can make roads 10 per cent cheaper than conventional roads.
How about a plastic road?
10-18% cheaper; lasts 15 years
The idea lies in exploiting the texture and water-resistant nature of plastic to construct roads. First, plastic wastes are segregated, cleaned and shredded to the size of 2-4 mm. It is then heated and coated over gravel. The laminated gravel is then mixed with bitumen to lay roads.
According to R Vasudevan, Dean of Thiagarajar College of Engineering in Tamil Nadu, who is the pioneer of plastic roads in India, usually 10 tonnes of bitumen is required to lay one km single-lane road. A plastic road of this size requires one tonne of plastic waste and nine tonnes of bitumen. This reduces the requirement of bitumen by up to 18 per cent. Besides, Vasudevan says, the technology significantly increases the strength and life span of roads as compared to conventional bitumen roads. “The reduced consumption of bitumen makes plastic roads cheaper, but they prove to be further cheaper, say by 10-18 per cent, in the long run as they do not require maintenance for at least 15 years,” says Vasudevan, who has obtained a patent for the technology. Besides, the technology provides a way to dispose of non-degradable plastic waste. One kilometre plastic road can consume one tonne of plastic waste. On an average, each individual in the country uses seven kg of plastic carry bags a year. Since 2011, the Tamil Nadu government has laid more than 2,000 km of plastic rural roads using Vasudevan’s technology.
Use fly ash in road, save soil and cement
20% cheaper; lasts 6-7 years
Fly ash, a waste produced by thermal power plants, can be used in place of soil to construct roads, says Vimal Kumar, senior scientist and former head of the Fly Ash Unit of the Department of Science and Technology. This would help save 20-30 million tonnes of fertile top soil used in widening roads and raising its levels every year.
Besides, ash ponds created to dump fly ash occupy thousands of hectares and contaminate the top soil. These ponds also host stagnant rainwater and wastewater, leading to serious health problems among people living in the vicinity. “Using fly ash in roads can also address this problem,” says Kumar.
Last year, the government issued guidelines asking states to use fly ash, despite its high price, in all roads within 100 km of its availability.
Experts say fly ash can be used as a soil stabiliser. It acquires the property of cement after it is mixed with lime. “When used in making cemented roads, it can reduce the use of cement by 50 per cent,” says Kumar. The technology also increases the life span of roads by about 15 years, he adds. “Production of one tonne of cement adds nearly the same amount of CO2 to the atmosphere,” Kumar adds.
Roads made from demolition waste
10-15% cheaper; lasts 5-6 years
Developed countries, including the US, the UK, France and Japan, use waste materials generated during construction, renovation and demolition of buildings as aggregates in laying roads. “These wastes are a mix of concrete, tiles, bricks and other construction materials and can be partially used as replacement of 35 per cent of aggregates in laying rural roads. But unfortunately their use is limited in India,” says Binod Kumar, senior scientist at CRRI. Kumar has done extensive research on using the waste in rural road construction.
Delhi alone produces about 3,000 tonnes of construction and demolition debris a day. Recycling and re-utilisation is an important strategy for management of such waste. This would also help reduce the demand-supply gap for aggregates, conserving depleting resources,” Binod adds. NRRDA plans to lay a rural road in Amabala, Haryana, using the technology.
Use cold-mix technology, lay roads round the year
10% cheaper; lasts 5-6 years
As the name suggests, cold-mix technology does not involve heating the bitumen. Instead, it uses bitumen emulsions, prepared by mixing bitumen with water. The slurry is then poured over the aggregates.
The biggest advantage of the cold mix technology is that it helps save precious diesel, used in heating bitumen while laying conventional roads. “On an average, this technology helps save about 1,500 litres of diesel per km,” says P K Jain, senior scientist with CRRI. It also aids faster black-topping of roads. Besides, unlike conventional roads, which are built only during the summer months, bitumen emulsion can be applied over damp aggregates and can be used to build roads around the year. This type of road is particularly suitable for north-eastern India that receives spells of rain over a longer period. Assam has constructed nearly 1,700 km of rural road in the past two years by using bitumen emulsion.
Experts say since the technology does not require high-end equipment, it can be used to build roads in Naxalite-affected areas.
Lukewarm response from states, communities
The IRC code is not the first attempt to make rural roads cost-effective and environment-friendly. Earlier, in May last year, MoRD had issued guidelines for using these technologies in 15 per cent of rural roads proposed by states. On December 19 last year, L C Goyal, a secretary at MoRD, wrote to all states and union territories to encourage non-conventional techniques and materials for rural road construction. “We have been insisting that state governments follow the guidelines since last year,” says Rajesh Bhushan, joint secretary of the Department of Rural Connectivity of MoRD. “But they were not following the guidelines on the pretext of lack of a rural road specification code,” Bhushan says. Now that IRC has released the code, Bhushan hopes that green rural roads may soon become a reality.
Several states and engineers are sceptic about the technologies. “Last year, an engineer from Karnataka, which has built 155 km of roads using coir and jute, wrote to his senior that blame of any failure should be passed to NRRDA, not him,” says Choudhary. The guidelines provide protection to engineers in case of failure of roads that use approved technologies.
As per guidelines, NRRDA should train engineers from each state about the new materials and technologies. But it is not able to organise regular workshops due to poor participation from states. Most states are yet to publish the estimated cost of materials that can be used in building roads. This is delaying the process of preparing a plan budget for the green rural roads.
The attitude of politicians and communities is no different. Gupta says politicians think the technologies would make roads in their constituencies weak and are opposing it. In areas where the government has built the roads on an experimental basis, people feel they are being cheated, he adds.
One only hopes that the hesitant officials and communities catch up with the times before it is too late.
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