Review of Hot In-Place Recycling Work of Asphalt Surface Layer on NH-152

Abstract

Indian road needs urgent rehabilitation for the existing asphalt roads. Overlay is the Conventional corrective maintenance of asphalt pavement in India, which involve a very large capacity of virgin aggregate and bitumen material which results in high mining as well as it lays footprint in ecological deterioration. Chief concerns for this problem are energy prices, aggregate shortages and the global warming .To address above problems several new highly developed techniques are being pursued to conserve energy and mother earth. One of the big names in industry is much trying to repave the present pavement using recycling process known as Hot in place recycling. After successfully completing many projects in India, TATA Eco Resurfaces Private Ltd., alias TERPL, recently successfully finished a highway pavement recycling work of 112 km lane (28km x 4 lanes) of Nh-152, using a Hot InPlace recycler, AR2000 regardless of mechanical, operational and new asphalt supply problems or difficulties which took place during the operation. The existing road surface had been 100% successfully reused and recycled with new mix added as designed. This is the first large scale HIR execution ever done as a single recycling project in Punjab. The AR2000, uses a number of equipment’s arranged in such a manner that all the mechanical work consisting softening of existing layer using hot air followed by scarping of existing layer, mixing and milling with new material repaving and finally compacting the new pavement layer with the help of vibratos ensure on the site recycling possible. Hence it consists number of machines like two numbers of pre-heaters, one number of pre-heater with attached miller and one number of post-heater mixer working one after other forming a train. The heating system rises the existing pavement surface temperature about 600 degrees to soften top layer so that the top layer can be obtained without damaging or crushing aggregates. The big advantage of utilizing AR2000 being that 100% recycling work of desired quality without varying original gradation can be achieved, which has been confirmed by a high quality control checks. The quality control was censured by incorporating, Marshall Test concerning Stability, and Fifth wheel bump indicator test to keep a check on roughness. 96 days were taken for the whole recycling work done by AR2000. The average operation speed was 1.48 km per day, which is far ahead of the speed of work by the conventional manual method. The AR2000 recycling work performed at NH-152 has secured the economic viability of HIR method by saving the mother earth from mining operations of about 13350 m3 virgin aggregate and 1698 metric tons of bitumen. In context of structural strength, the marshal load came out to be 1276 kN and roughness value in term of BI scale being 1380 mm/Km which is well above the required benchmarks as per IRC