Application of Wicking Geotextile for Pavement Infrastructure on Expansive Soil

Abstract

Problematic soils cover a majority of North Texas, which are primarily characterized by high plasticity and expansive nature. Moisture intrusion plays a pivotal role in determining the long-term performance of such soils when subjected to repetitive axle loading. Highways constructed on such subgrade often fail to perform satisfactorily due to rutting, cracking, and differential movements during the seasonal moisture variation. Calcium-based stabilizers are traditionally used by existing practitioners to treat such problematic subgrade. However, treatment with calcium-based stabilizers fails to perform suitably over the pavement life due to durability and leaching problems. Besides, treatment with calcium-based stabilizers involves significant construction delay and has a detrimental impact on the environment. As an alternative to these shortcomings, a newly available geotextile with a wicking ability has been used to construct a test section in North Texas. The geotextile layer, installed at the interface of the base and subgrade layers, performs a two-fold function. Besides the primary function of providing separation and reinforcement to the subgrade, the wicking ability of this geotextile helps moisture redistribution within the pavement layers. The performance of the pavement section was closely monitored using several sensors. Initial observations suggest that the geotextile can suitably redistribute the moisture within the subgrade. The pavement section showed an improved resilience to deformation from traffic load as compared to the control section.