Wicking geosynthetics for drainage of pavement in both saturated and unsaturated conditions

Abstract

The most important component of a well-performing road is drainage. The efficient removal of water from the base and subgrade of a road structure can significantly increase its life expectancy and quality of ride by improving the underlying soil's bearing capacity, maintaining the base course strength and minimising longitudinal edge cracking, all of which lead to premature failure of the riding surface. Although many measures are taken to improve the drainage profile of pavements, challenges still exist. These can include the lack of drainage in unsaturated soil conditions and the contamination of the base course with fines from the underlying subgrade due to saturated pumping. New high-strength geosynthetics have been developed that incorporate wicking yarns, which drain both saturated and unsaturated soils. An examination will be made of how these new geosynthetics work and how they can maintain, and even at times increase, the resilient modulus of the subgrade and pavement structure.