Load associated cracking and permanent deformations are the common distress found on flexible pavements. Rutting is one of the major failure mechanisms in flexible pavement. The present study focuses on the measurement of rutting using Accelerated Pavement Testing Facility. For the measurement of rutting, thepavement was instrumented with a Multi-Depth Deflectometer (MDD) to measure the interfacial layer deflections for determining permanent deformation of each layer. The pavement was designed as per Indian Road Congress specification and constructed as per the Indian Highway Ministry specification. The rutting contribution of each layer from the MDD data acquisition system has been reported here. It has been found that at standard axle load, the subgrade is safe from rutting. However, when an axle with higher loading was applied, distress was developed in subgrade level. Furthermore, the strain values were calculated at subgrade level from MDD data and compared with the output from computational analysis using a finite element program. Finally, a high-resolution laser profilometer was used for measuring the rutting at surface of the road. The pavement was monitored and tested until the failure criteria of 20 mm rutting on the surface are reached.

Contributors:Khan S, Nagabhushana M N, Hossain K, Tiwari D.