Patent Filing No. 1735/KOL/2007 dated 27-07-2007
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IIT Kharagpur has developed a new
technology for the construction of roads with flexible concrete at a
cost lower than that of a black top road. The expected life can be
about 15-20 years. The method of construction makes the concrete flexible, and
the surface does not crack. It is labour based, maintenance free and ideally
suited to rural road construction as per the policy of the government where
employment generation is very important for the empowerment of the poor. It
requires less initial cost than the conventional pavement. The technology can
also be used for overlays over damaged black top roads, pavements of footpath,
roads of housing complex, container yards, haul roads for transport of mineral
products, parking area of heavy vehicles etc.
During August 22 - 25, 2014 a technology transfer workshop took place in the Dept. of Civil Engineering, IIT Kharagpur for the engineers of Rural Engineering Dept.of Uttar Pradesh who are looking after Prime Minister's Gran Sadak Yojana (PMGSY) activities of that state. This was the second batch of engineers from Uttar Pradesh who got trained here. The third batch will commence training on Sept. 05, 2014. Earlier such technology transfer workshop was conducted for engineers of Bihar, Jharkhand, Madhya Pradesh, Rajasthan, Mizoram state and for NRRDA (National Rural Road Development Agency). 
Prof. B. B. Pandey of Dept. of Civil Engineering briefly explained the technology to us. The foundation of a road is prepared as per standard
specifications for road construction. A formwork of cells
of fresh or recycled polyethylene sheets is placed across the full width of
road under tension. Edge protection is provided by brick on end
edge or concrete blocks. A concrete mix is filled into the cells and compacted by a
skid/pan vibrator.. The cement content is such that the 28day characteristic
compressive strength is a minimum of 30 Mpa for a village road. The strength
should be at least 40Mpa for container yard, haul roads, parking yards for
heavy vehicles. Elastic modulus of the concrete layer as determined by FWD
is found to be over 2500MPA and 100mm of flexible concrete layer is equivalent
to 220mm of Water Bound Macadam base and 130mm of Bituminous Concrete. 
In the valedictory function of this workshop, Prof. K. S. Reddy of Dept. of Civil Engineering mentioned that Government of India now insists on and encourages use of novel technology and there is a risk mitigation strategy to overcome our concern to adopt something new fearing that it might not work. We were told that roads on this novel technology have been constructed in West Bengal,
Karnataka and Mizoram. Other states like Rajasthan, Bihar, Jharkhand have initiated measures for the construction of cell filled concrete
pavements immediately after the current
monsoon. We also learnt that in one field level implementation, the cells are
being stitched by a group of women
generating an employment for 300 man-days per KM of road that is 3.75m wide.To know more about this technology and the procedure for technology transfer, one may contact Prof. B. B. Pandey (Link), Prof. K. S. Reddy (Link), Dean, SRIC (Link), PIC, IPR & IR (Link).
