Maharashtra Government has undertaken an ambitious project, the first-of-its-kind (distance wise) in the country. The project has a big potential of using fly ash as a construction material. A glimpse of the project has been compiled by Sudhir Paliwal and Dr Ajitkumar Bhonsle.
Mumbai Nagpur Super Communication Expressway-also known as Maharashtra Samruddhi Mahamarg under construction-is a 701 km long, six-lane expressway, connecting the two capitals of Maharashtra - Nagpur and Mumbai. The expressway will run through 10 districts, 26 tehsils, and 390 villages in the State, and is expected to cut travel time between the two cities to eight hours. The project is expected to cost Rs 46,000 crore and requires the acquisition of 8,603 hectares of land.
The Maharashtra State Road Development Corporation is the nodal agency responsible for executing the project, which comprises building a completely greenfield expressway, designed for speeding up to 150 km/h on flat terrain and up to 100 km/h on the mountainous terrain of the Western Ghats section. The State Government also plans to build 24 townships along the route, which will include state-of-the-art healthcare facilities, skill management centres, IT parks and educational institutions. A total of 20,820 hectares of land is to be acquired for the project across 10 districts, out of which 8,520 hectares will be used for the highway, while 10,800 hectares would be for building townships.
The aim of the super communication expressway is to create connectivity to the last mile with best public transport facilities for quick and easy movement of people and goods. The expressway will enable a large population to have easy access to major centres in Maharashtra for a wide range of self-employment and wage employment opportunities, business, trade, education, health care and other necessary services.
Samruddhi Mahamarg Expressway
The expressway will pass through 10 districts, namely Nagpur, Wardha, Amravati, Washim, Buldhana, Aurangabad, Jalna, Ahmednagar, Nashik and Thane. It will connect Nagpur to Mumbai and have direct connectivity with the country's largest container port - JNPT. This will enhance export-import trade of the State. Inter-connecting highways and feeder roads would be constructed to connect all important cities and tourist places along this route. This will connect another 14 districts, namely Chandrapur, Bhandara, Gondia, Gadchiroli, Yavatmal, Akola, Hingoli, Parbhani, Nanded, Beed, Dhule, Jalgaon, Palghar and Raigad. In this manner, a total of 24 districts in Maharashtra will be connected via this expressway.
Major tourist destinations in the State will also be connected to the expressway. The expressway, having a total width of 120 m with a central median of 22.5 m, will follow the international standards of design. There will be eight lanes, four on each side. In case there is a need to increase lanes on either side, a provision has been made in the centre of the expressway. Thus, no more land will be required for expansion in future. It will have service roads on both sides that will connect through underpasses.
The expressway will have around 50+ flyovers, 24+ interchanges, over five tunnels, 400+ vehicular and 300+ pedestrian underpasses provided at strategic locations. These underpasses and flyovers will be beneficial to those vehicles leaving or joining the expressway without disturbing the traffic flow. It will also benefit local citizens to go about their travel without any hindrance and also prevent accidents.
Extensive landscaping, tunnel lighting, bridge beautification, improved street lighting and digital signage will be used throughout the length of the expressway. Maximum locally available material, fly ash and plastic will be used to construct the expressway wherever possible. Rainwater will also be harvested from the expressway. The entry and exit at the expressway will be managed and toll will be charged based on the distance travelled. The toll collection is proposed to be automated. The expressway will be a Zero Fatality Mahamarg; it will have CCTV surveillance and free telephone booths at every 5 km to allow reporting in case of any accidents and emergencies. Utility Mahamarg along the expressway will be provided for OFC cables, gas pipelines, electricity lines, etc.
In case of any emergency, natural disaster or in a war-like situation, a facility to land an airplane on the expressway is proposed by temporarily converting the expressway to a runway. The Maharashtra Samruddhi Mahamarg will link the State of Maharashtra to the Delhi-Mumbai Industrial Mahamarg and the Western Dedicated Freight Mahamarg. Parts of Maharashtra will have direct connectivity to these Mahamarg and JNPT, the country's largest container port. This, in turn, will enhance the EXIM trade of the State.
Advantages of using fly ash
The Indian Roads Congress (IRC) guidelines IRC:SP:58-2001 provide salient details regarding design and construction of road embankments using fly ash. Utilisation of fly ash will not only minimise the disposal problem but will also help in utilising precious land in a better way. Construction of road embankments using fly ash, involves encapsulation of fly ash in earthen core or with RCC facing panels. Since there is no seepage of rainwater into the fly ash core, leaching of heavy metals is also prevented. When fly ash is used in concrete, it chemically reacts with cement and reduces any leaching effect. Even when it is used in stabilisation work, a similar chemical reaction takes place, which binds fly ash particles. Hence chances of pollution due to use of fly ash in road works are negligible.
Fly ash is a lightweight material, as compared to commonly used fill material (local soils), therefore, causes lesser settlements. It is especially attractive for embankment construction over weak subgrade such as alluvial clay or silt where excessive weight could cause failure.
Fly ash embankments can be compacted over a wide range of moisture content, and therefore, results in less variation in density with changes in moisture content. Easy to handle and compact because the material is light and there are no large lumps to be broken down. Can be compacted using either vibratory or static rollers.
High permeability ensures free and efficient drainage. After rainfall, water gets drained out freely ensuring better workability than soil. Work on fly ash fills/ embankments can be restarted within a few hours after rainfall, while in case of soil it requires much longer period.
Considerable low compressibility results in negligible subsequent settlement within the fill.
Conserves good earth, which is precious topsoil, thereby protecting the environment.
Higher value of California Bearing Ratio as compared to soil provides for a more efficient design of road pavement.
Pozzolanic hardening property imparts additional strength to the road pavements / embankments and decreases the post construction horizontal pressure on retaining walls.
Amenable to stabilisation with lime and cement.
Can replace a part of cement and sand in concrete pavements thus making them more economical than roads constructed using conventional materials.
Fly ash admixed concrete can be prepared with zero slump making it amenable for use as roller compacted concrete.
Considering all these advantages, it is extremely essential to promote use of fly ash for construction of roads and embankments.
Use of fly ash in road works results in reduction in construction cost. If environmental degradation costs due to use of precious top soil and aggregates from borrow areas quarry sources and loss of fertile agricultural land due to ash deposition, etc. is considered the actual savings achieved are much higher.
Govt initiatives for fly ash utilisation in roads
Use of fly ash is mandatory in Road construction: As per para 5 of MoEF&CC notification dated November 3, 2009 - "No agency, person or organisation shall, within a radius of 100 km of thermal power plant undertake construction or approve design for construction of roads or fly-over embankment with TOP SOIL."
As per the para No.2 (14) of MOEF&CC notification dated January 25, 2016 - "The coal or lignite based thermal power plants shall within a radius of three hundred kilometres bear the entire cost of transportation of ash to the site of road construction projects under Pradhan Mantri Gramin Sadak Yojna and asset creation programmes of the Government involving construction of building, road, dams and embankments.
Maharashtra State has notified Ash Utilisation Policy - 2016 and constituted Maharashtra State Fly Ash Council under the Chairmanship of Chief Secretary, Maharashtra. As per the State ash policy, point No. 1, 2 & 3 under para "Government Decisions", - "fly ash to be transported free of cost for Government infrastructure projects, roads construction by the ash producers i.e. thermal power plants"
In compliance of MoEF&CC notifications NTPC has been issuing ash free of cost for road construction projects and also entering in to MoU with NHAI for bearing transportation cost of ash. More than 100 lakh tons of Fly Ash is utilised in NHAI projects in Maharashtra and other States where fly ash is generated.
Samruddhi Mahamarg between Nagpur and Mumbai is passing within 300 km radius of several power plants like Reliance Butibori, Ideal Energy, Mahagenco Khaprkheda/Koradi, NTPC Mouda, Ratan India Amraoti, Mahgenco Paras, Bhusawal, Parli & Nasik, Tata Power, Adani Power, etc.
The Ministry of Road Transport & Highways, Government of India also issued following directions wide letter dated August 27, 2018: The use of fly-ash in road construction is permitted as per the standards and specifications evolved by the Indian Road Congress. The physical and chemical properties of fly ash and the design methodology to be adopted for embankment construction has been specified in IRC:SP:58:2001: "Guidelines for use of fly-ash in road construction". Section 305 i.e. "Embankment Construction" of MoRT&H specifications for road and bridge works lays down the specifications for use of fly-ash in embankment construction.
Compliance to IRC specification No.SP:58 of 2001 related to use of fly ash has been made mandatory by the Ministry of Environment Forests & Climate Change by issuing an amendment to their fly ash notification while undertaking construction or approve design for construction of roads or flyover embankment.
The Ministry of Environment Forests and Climate Change (MoEF&CC) has issued various notifications for fly ash utilisation. The principal notification was issued on 14-9-1999, which was subsequently amended vide notifications dated 27-8-2003, 3-11-2009 and 25-1-2016. As per the notification of MoEF&CC, it is mandatory to use fly ash in the construction of road or flyover embankments within a radius of 300 km of a thermal power plant. Further, the relevant content of the notification dated 25-1-2016 of MoEF&CC regarding road/ flyover embankment construction are as under:
Para 14: The coal or lignite based thermal power plants shall within a radius of three hundred kilometers bear the entire cost of transportation of ash to the site of road construction projects under Pradhan Mantri Gramin Sadak Yojana and asset creation programmes of the Government involving construction of buildings, road, dams and embankments.
The issue of lesser off-take of fly-ash in road construction activities of the Ministry of Road Transport & Highways and its executing agencies (NHAI, State PWDs and NHIDCL) has been reviewed at the level of the Ministry. It was pointed out that the thermal power plants have been found to be reluctant to bear the transportation costs in accordance with the latest notification issued by the MoEF&CC on the subject. Accordingly Secretary, MoRTH took up the matter with the Secretary, Ministry of Power and the CMD of National Thermal Power Corporation (NTPC). The CMD of NTPC clarified that they had already issued instructions in this behalf to the officers-in- charge of all the NTPC plants. The availability of fly ash at various stations of NTPC is available at NTPC official web site www.ntpc.co.in under the tab "Ash Availability". The names of responsible persons along with telephone number/mobile number/e-mail address to communicate for issues of pond ash are mentioned. The same is also available in the app "ASHTRACK" launched by the Ministry of Power.
As per the Central Electricity Authority during 2017-18 about 196 million tonnes of fly ash was generated in India out of which only 131 million tonne could be utilised. However in roads and flyovers only 6.67 million tonne is utilised, which is just 3.4 per cent of total utilisation.
There is huge potential of utilisation of fly ash in roads like Samruddhi Mahamarg. Use of fly ash is mandatory in road construction: As per para 5 of MoEF&CC notification dated November 3, 2009 - "No agency, person or organisation shall, within a radius of 100 km of thermal power plant undertake construction or approve design for construction of roads or fly-over embankment with top soil."
As per the para No.2 (14) of MOEF&CC notification dated January 25, 2016 - ôThe coal or lignite based thermal power plants shall within a radius of three hundred kilometres bear the entire cost of transportation of ash to the site of road construction projects under Pradhan Mantri Gramin Sadak Yojna and asset creation programmes of the Government involving construction of building, road, dams and embankments".
In compliance of MoEF&CC notifications NTPC has been issuing ash free of cost for road construction projects and also entering in to MoU with NHAI for bearing transportation cost of ash. More than 100 lakh tonne of fly ash is utilised in NHAI projects in Maharashtra and other States where fly ash is generated.
In the meeting of Maharashtra State Fly Ash Council held under Chairmanship of Chief Secretary in March 2018, MSPGCL and PWD were directed to sign MOU for fly ash utilisation for Samruddhi Mahamarg.
"In December 2018, an agreement was signed between Maharashtra State Power Generation Company and Nagpur Mumbai Super Communication Expressway to utilise about 300 lakh tonnes of pond ash and 15 lakh tonnes of dry fly ash for entire 700 km road.
ABOUT THE AUTHORs: Sudhir Paliwal is an Expert Member of the Maharashtra State Fly Ash Council Mumbai.
He can be contacted on: 8291089301. Dr Ajitkumar Bhonsle is an expert and advisor on use of fly ash. He can be contacted on: 9821127987