Hot Mix Recycling of Asphalt Pavements It's Long Overdue in India!

Prof. Prithvi Singh Kandhal, Associate Director Emeritus, National Center for Asphalt Technology Auburn University, Alabama USA.
Introduction
Recycling of existing asphalt pavement materials to produce new pavement materials results in considerable savings of material, money, and energy. The specific benefits of recycling can be summarized as follows: (a) substantial savings over the use of new materials, (b) conservation of natural resources, (c) performance equal or even better than new materials, (d) pavement geometrics is maintained, and (e) saving of considerable amount of energy compared to conventional construction techniques. The last benefit is very important due to the recent urgent need for reducing greenhouse gases that is, reducing carbon footprint thereby earning carbon credits for India.Over the years, recycling has become one of the most attractive pavement rehabilitation alternatives in developed countries. Unfortunately, asphalt pavement recycling is yet to take off in India despite the current ambitious road building programme underway.
The Asphalt Recycling and Reclaiming Association define five different types of recycling methods: (1) Cold Planing; (2) Hot Recycling; (3) Hot In Place Recycling; (4) Cold In-Place Recycling; and (5) Full Depth Reclamation. Only hot recycling of asphalt pavements at a central plant will be discussed in this article in the context of 4-laning and 6-laning of India's state highways and national highways wherein road paving bitumen worth crores of rupees is being buried rather than recycled. The cost of bitumen is about the same as sugar that is: Rs.30-35 per kg. Will we bury sugar under our highways?