Laboratory tests to evaluate effectiveness of wicking geotextile in soil moisture reduction

A new type of woven geotextile, referred to as wicking geotextile, was developed and introduced to the market. Since this wicking geotextile consists of wicking fibers, they can wick water out from unsaturated soils in a pavement structure thus resulting in an increase of soil resilient modulus and enhance performance of roadways. In this study, a physical model test was developed to evaluate the effectiveness of the wicking geotextile in soil moisture reduction for roadway applications. A test box with a dimension of 1041 mm in length, 686 mm in width, and 584 mm in height was used in this study. Two HDPE plastic panels were used to separate the box into two sections, one containing a dehumidifier and the other backfilled with soil. The dehumidifier was adopted to collect the water, which was wicked out from the soil by the wicking geotextile and evaporated into air. Test results show that (1) the wicking geotextile wicked water out from the soil even at the moisture content close to the optimum moisture content and (2) the comparison of soil moisture contents before and after rainfall demonstrated that the wicking geotextile maintained the soil moisture contents after rainfall close to those before rainfall and had an effective distance for the soil moisture reduction.