Effectiveness of Wicking Geotextile in Mitigating Freeze-thaw Problems of Aggregate Bases with Fines

Abstract

Freeze-thaw of soil is a phenomenon which usually happens in northern regions of the Earth. It causes change of soil volume and reduction of soil strength and modulus that can damage buildings, roadways, and so on. How to mitigate the freeze-thaw problem in northern regions has become a common issue. Wicking geotextile, which can remove water from an unsaturated soil by special fibers, was developed by the manufacturer to mitigate the freeze-thaw problem. However, limited studies have been conducted so far on the effectiveness of this geotextile in mitigating the freeze-thaw problem. The objective of this study is to investigate the performance of wicking geotextile in mitigating freeze-thaw problems of aggregate bases with fines. Plate loading tests were conducted under repeated loading used to evaluate this material. Eight repeated plate loading tests were conducted under four different conditions: (1) bases compacted at optimum moisture content, (2) saturated bases without drainage, (3) saturated bases with drainage, and (4) saturated bases with drainage and freeze-thaw process. Two types of woven geotextiles (one with the wicking function and another without the wicking function) were used to reinforce the bases. One unreinforced plate loading test was conducted under each condition as a control section. The data analysis included the performance improvement factors, the subgrade reaction modulus of the aggregate bases, the elastic modulus of the base course, and the permanent displacement of the base course. The test results showed that both geotextiles effectively reduced the permanent deformations of the bases. Moreover, the wicking geotextile-reinforced base courses after drainage had smaller displacements as compared with other base courses because the removal of water from the base courses by the wicking geotextile increased the base strength and modulus and minimized the freeze-thaw potential of the bases.