SEM Analyses on the Long-Term Drainage Performance of a New Wicking Fabric

A new woven geotextile with wicking fibers (also named as “wicking fabric”) has been recently developed to deal with excess water within pavement structures. The wicking fibers have specially designed deep grooves that can maintain saturated to hold and transport water under unsaturated conditions. Both laboratory and field tests have proven the effectiveness of the wicking fabric in dehydrating the road embankment. In the engineering applications, the wicking fabric was exposed to the surface of the road embankment for the water evaporation purpose. The long-term drainage performance of the wicking fabric may be influenced by such potential issues as the permanent deformation, clogging, salt concentration, and mechanical failure of the wicking fibers. To evaluate the long-term drainage performance of the wicking fabric, samples were collected from a field test section. A scanning electron microprobe (SEM) was used to analyze the severities of the potential issue. Test results indicated that the permanent deformation is expected in the wicking fabric. However, the wicking fabric can still work effectively to wick water out of pavement structures.