APPLICATION OF GEOSYNTHETICS IN FLEXIBLE PAVEMENT

Abstract

In India, most of the flexible pavements are need to be constructed over weak sub-grade soil having low
modulus values. This Study examined the basic engineering and geotechnical properties of poor sub-grade soils using
geosynthetics like Woven Geotextile to improve its strength. CBR tests were carried out by placing the Woven Geotextile
in single layer at depths 0.33H, 0.66H and 0.8H (H- height of mould in CBR test) from bottom of mould under soaked
condition to determine the strength of the soil. Flexible pavement was designed for both fatigue and rutting life of
100MSA at 90% reliability, when the Woven Geotextile was placed at three different depth in subgrade soil The critical
strain value for both fatigue and rutting life were analyzed by IITPAVE software and the allowable strain values were
computed by IRC: 37-2012. The result shows that the strength of subgrade soil was considerably increased by
introducing Woven Geotextile reinforcement in the soil. From this study, single layer of Woven Geotextile introduced at
the depth of 0.8H from the bottom of the mould shows better performance as compared to those when Geotextile was
placed at other depth of mould. Pavement thickness and Cost for Construction of Pavement reduces when Geotextile was
placed at different depth of subgrade soil with minimum being when Geotextile placed closer to top of mould.