NHAI trials reclaimed bitumen on stretch of Chennai-Tirupathi National Highway

The Chennai-Tirupathi National Highway, currently under widening, witnessed a successful trial of reclaimed bitumen on a 1 km stretch. The road, which had been in use for several years, saw its top bituminous layer lose elasticity. CSIR-Central Road Research Institute (CSIR-CRRI) devised a rejuvenating additive for cold-milled material to strengthen it for reuse in road laying.

The technology, developed two years ago, was initially tested on small sections. CSIR-CRRI has transferred the technology to Ooms Polymer Modified Bitumen Pvt Ltd. (Ooms India) for commercial production. Ooms India and Oriental Structural Engineers Private Limited (OSEPL), widening the road, along with the National Highways Authority of India (NHAI), are collaborating on this trial.

The Indian Roads Congress (IRC) code currently permits the reuse of 30% bitumen for road re-laying, but this innovation allows for 60% of reclaimed material, typically discarded, to be used. This advancement could reduce dependency on foreign exchange and pave the way for recycling bitumen in the long run. The research team behind the additive includes Ambika Behl, Rajiv Kumar, and Siksha Swaroopa Kar.

The Institute recently visited the site at Tiruvallur to ensure the methodology was correctly followed. Tamil Nadu has been reusing 30% bitumen where feasible, but the prospect of using 60% is intriguing. The IRC Code will determine its integration.