Effect of the Position of Geotextile on the Performance Parameters of the Flexible Pavement

Abstract

The major deterioration of the flexible pavement is due to the combined effect of fatigue cracking caused by excessive horizontal strain at the bottom of the bituminous layer and rutting deformation caused by excessive vertical strain at the top of subgrade layer. For designing the flexible pavement, it is necessary to determine the minimum thickness of the road crust, required to withstand the expected fatigue life and rutting life. The critical value of fatigue and rutting life are analyzed by programme IITPAVE software and these critical values are less than the allowable values as computed by IRC: 37-2012. In this study, we have to design the flexible pavement for fatigue and rutting life =100 msa at 90 and 80% reliability, when the non-woven geotextile are placed at three different depths of subgrade soil samples. It is observed that the CBR value increases, when the geotextile is placed at depth 0.33, 0.66 and 0.85 H from the bottom of the mould and there is a percentage increase of saving of DBM layer and granular layer thickness. For fatigue life of 100 msa, the maximum reduction of DBM layer is 30.73 and 28.4% in sample A, and 25.8 and 25.7% in sample B, at 80 and 90% reliability. For rutting life of 100 msa, the maximum reduction of granular layer thickness is 44.9 and 46.08% in sample A, and 33.82, 32.85% in sample B, at 80 and 90% reliability