Evaluating the Performance of Wicking Geotextile in Providing Drainage for Flexible Pavements Built over Expansive Soils

The longevity and performance of a pavement section depend on the characteristics of the subgrade soil. A majority of the pavements in North Texas, U.S., are constructed on expansive soils. The deterioration of the pavement performance because of rutting, cracking, and differential heaving is a regular phenomenon in the regions predominantly distributed with expansive soils. The pavements, particularly those built for low-volume traffic conditions, experience distress because of the high swelling and shrinkage characteristics of the underlying problematic soils. Geosynthetics have been traditionally used to improve such poor subgrades because of their many benefits, such as ease of installation, and ample mechanical and hydraulic properties. In the last decade, a newly available wicking geotextile, with a moisture redistribution capacity, has been developed to improve the performance of pavements constructed over expansive and frozen soils. In this study, small-scale laboratory and full-scale field studies were conducted to comprehend the wicking ability of this innovative geotextile in an expansive soil environment. Full-scale test sections were constructed with reclaimed asphalt pavement aggregate and traditional crushed stone aggregates in the base layer near North Texas. Details of the construction and instrumentation procedure are discussed in this paper. A comparative study between the performance of the pavement sections subjected to traffic loads and moisture intrusion was also performed. Furthermore, the rutting life of the sections, estimated using a linear elastic model, was compared and validated using the in situ data. The observations during the initial phase indicated that the wicking geotextile has the potential to improve the long-term pavement performance.