Rehabilitation of Existing Indian National Highways with Cold in-place Recycling Technique using Foamed Bitumen "A Cost-Effective Tool."

Abstract

Timely rehabilitation of existing old BT roads using asphalt recycling techniques to regain the structural capacity and the functional serviceability up to a desirable level would be a cost-effective and eco-friendly option. In the present study, an attempt has been made to produce an economical design for the rehabilitation of Chennai-Tada Road, N.H-5, by recycling the existing pavement material through a cold in-place recycling technique using foamed bitumen. Also, to work out a mix design for the base binder course and find out its cost-effectiveness. A complete assessment was carried out for the functional and structural failure from km 22.000 to 54.365. Main parameters considered rutting, cracking and shoving and severity pavement condition indicators were assigned as low, medium and high, and the Benkelman Beam deflection method was used to determine structural inadequacy. Cores were taken from distressed chainages. Reclaimed asphalt pavement (RAP) material was collected using a miller machine. The mix design was undertaken based on the guidelines of Wirtgen Cold Recycling Technology, TG2 Second revision and IRC- 37: 2012. The blending of aggregate was done as per the specified grading requirement. The sample was prepared with different foaming binder content varies from 1.5% to 2.5% and successfully produced   BSM mix with 82%  RAP material. Test results obtained classifies the mix as BSM1, which can be used for heavy traffic. The pavement was designed with the composition of BSM in 240mm thickness as an alternative option to the Dense bituminous macadam (DBM) layer along with the fresh bituminous concrete layer of 40 mm thickness.