In the coming days, one can look forward to a smooth drive around the city. To increase the durability and improve the surface finishing of roads, the New Delhi Municipal Council (NDMC) has adopted a new technology: polymer mixed bitumen (PMB).
On Monday, NDMC's Engineering Department started work on Madhavrao Scindia Marg using the PMB technique that provides an anti-skid surface. The plan is to use it on 29 roads, covering 40-45 km.
"It is for the first time in Delhi that PMB would be used on a large scale. Only the Public Works Department (PWD) has used this technique, that too sparingly and in pilot projects," said NDMC Engineer-in-Chief KK Mutreja.
Other roads in line for this treatment include Kasturba Gandhi Marg, Rajpath, Ferozeshah Road, Africa Avenue, Ashoka Road, Bangla Sahib Marg, Satya Marg, Tansen Marg, Teen Murti Marg, Tolstoy Marg, Udyan Marg, Vinay Marg, South End Road, Shantipath, Jantar Mantar Road, Pandara Road, Hanuman Road, Sansad Marg, Aurobindo Marg, Jor Bagh Road, Safdarjung Road and Maulana Azad Road.
So how does this technique work? PMB helps in better binding, which ensures that there is little wear and tear of the road surface during monsoon. The average life span of a road constructed using conventional techniques is five years. The use of PMB can extend the road life by two years. But the cost goes up by 15-20 per cent.
Since using PMB allows scope for improved road surface, NDMC is targeting to reduce the roughness of the roads by half.
To ensure good quality, the Central Road Research Institute (CRRI) has been roped in for third party quality assurance. Once the roads are ready, the CRRI experts would inspect each stretch and the payment would be released to the contractor only after they issue a satisfactory certificate.
Another 23 roads have been identified for carrying out micro-filming. This involves laying a very thin but strong layer on a road whose surface has been damaged. "This technique is used where it is not possible to raise the height of the road," said Mutreja.
NDMC is aiming to rope in private contractors who carry out on-the-spot recycling of road material and re-laying of surface. “To save on material, re-cycling laid roads is the only option. However, it is an expensive process and would be beneficial only in case of recycling long stretches," said Mutreja.
In-situ road recycling involves special machinery, in which the road surface is melted by jets of hot air (600º C), while another machine scrapes out the old road. "The scraped-off material is tested on the spot and the deficient raw material are added and the mix is re-laid," said Mutreja.