GUWAHATI: The Assam government had recently introduced a new method – milling and recycling – of road repair and construction in the city. A pilot project was kicked off in July this year, under the guidance of Public Works Department (PWD) minister Himanta Biswa Sarma.
For the pilot project, four key areas were identified with four contractors taking responsibility of each of their respective areas. New machineries for milling of Wirtgen make from Germany, costing around Rs 2 crore, were also brought to the city and a total budget plan of approximately Rs 31.25 crore was prepared for the repair works.
The roads selected for the pilot projects are: City Division 1 that includes FC Road, MC Road, HB Road including Cotton Hostel Road and Town Club Road and part of Kahilipara Road; City Division 2 that includes Kalakshetra Road and Hatigaon Bhetapara Road; City Division 3 that includes Mother Teresa Road and part of Kahilipara Road and the AT Road under State Road Division.
The combined length of the roads have been calculated at 14.633KM with City Division 3 covering the largest area of 4.5KM (1KM of Mother Teresa Road and 3.5KM of Kahilipara Road) and State Road Division covering the least area of 2.3KM.
“Rapidly rising height of roads in Guwahati – that go up after every coat of resurfacing – has long been an issue. As a solution we introduced a new technology of milling and recycling on July 7, 2018 on Hem Baruah Road,” PWD minister Himanta Biswa Sarma said.
The pilot project was inaugurated on July 7 using advanced German technology to repair and build the roads. The inaugural ceremony was held at Hem Baruah Road in front of the sessions court. Sarma was accompanied by education minister Siddhartha Bhattacharya and minister of state for power and PWD Topon Kumar Gogoi.
To ensure layers of roads do not add up to their thickness, this new technique trims the upper part, recycles it and uses it in laying the new layer. According to PWD officials, 20-30 per cent of the stone chips and bitumen can be recovered through milling and recycling process. Milling involves scraping of the road to a depth of 20mm to 90mm.
The material is then transported to the recycling plant where stone chips and bitumen are separated. The recovered material is then carried to the road construction site, prepared to be used after mixing with fresh materials.
“Laying a new layer of asphalt on top of an old and damaged one is only a temporary solution. Cracks migrate through the new materials and destroy them in a short time. They also add up to the thickness of the road, resulting in raising the pavement height while the houses constructed on either sides of the road remain at the same height that they were. This causes multiple problems especially that of water flowing towards the houses,” Bhupendra Chandra Sarma, executive engineer of Guwahati City Division 1 informed G Plus.
He added that in the process of milling and recycling, a broken area is removed using cold milling equipment and then the extracted material is recycled forming a part of the new asphalt. This new material is then used to pave the worn out part, creating a new layer. This way, the built up area of the road is leveled with the height at which houses are constructed.
The aim of the project is to keep the road levels intact, while reducing the cost of construction and achieving longevity. Other advantages of using milling technology include smoothening of the road improved riding quality.
Superintendent engineer of PWD, city circle, Dilip Hazarika said, “This process is being used by our department for the first time. However, if the pilot project becomes successful, the same technology will be used in other parts of the state too.”
“I believe using this technology will bring a new revolution to road building and repairs in the entire state of Assam,” said Siddhartha Bhattacharya, Guwahati Development Department (GDD) minister.
