The public works department (PWD) has launched the state-of-the-art zero-emission mastic asphalt technology for relaying Kidderpore Road in Kolkata. The automatic machines and mixing plants, imported from Germany, are being used to spread layers on the road surface without causing environmental emissions. A senior official of the state public works department (PWD) told the media that the hot mix prepared in the imported machines spreads and solidifies in less than an hour. Traffic can move just an hour after the mastic layers are laid, thus minimising the requirement for prolonged traffic blocks and causing the least inconvenience to commuters. In October 2018, they banned asphalt baking by the roadside. In March, the PWD had employed the same sophisticated method and zero-emission German technology for relaying VIP Road. The German agency was selected for repaving major roads. The mixing plant is located near where the machines have been ferrying the hot mix material on trucks in six thermal containers. The special carriers equipped with thermostats that guarantee the temperature of the mix stays at 200°C have been transporting the mastic asphalt to the site at night. The mix is then laid on the road, the official said. He said that the pollution-free technology for repaving roads is currently used only in a few cities in India. The whole stretch is cordoned off as the workers re-lay the road utilising advanced road-laying machines at night. On Saturday, a visit to Kidderpore Road showed the mechanised mastic surface of the freshly paved thoroughfare. The pre-existing layer of mastic was scraped off on both flanks before dense bituminous macadam was put in its place to assure there were no undulations on the road. A traffic block is required only at night because of the mechanised asphalt’s easy pasting features which will present better durability and reduce periodic maintenance prices. The option for mastic asphalt is either bitumen or concrete. Since the Kolkata thoroughfares get flooded during monsoon, bituminous surfaces wear off fast. Image Source Also read: Govt mandates use of concrete elements to push green roads