Long-Term Performance of Wicking Fabric in Alaskan Pavements

Abstract

Beaver Slide is near 177.8 km (110.5 mi) on the Dalton Highway and the road gradient is approximately 11%, built on a hill side. Each year, soft spots, also commonly named as frost boils, were observed starting from late April and lasting for the entire summer. The frost boils have resulted in an extremely unsafe driving condition and frequent accident occurrences. Conventional repair methods cannot effectively solve this issue. A newly developed geotextile, which has high specific surface area, was installed in the selected test section to mitigate the frost-boil issue in August 2010. This type of geotextile can provide high wettability and relatively high suction (capillary force), consequently be able to laterally transport water (a high-directional transmissivity) under unsaturated conditions. Test results over the initial 2 years had proved the effectiveness of the geotextile to alleviate frost heave and the subsequent thaw-weakening issue. However, there were still some concerns regarding its long-term performance, such as clogging of the microscopic drainage channels and mechanical failures. The data collected during the past 5 years were used to analyze and evaluate the effectiveness of the wicking fabric. A scanning electron microscope was used to explore the interaction between the wicking fabric and in situ soils, and to determine the condition of the fabric 5 years after the installation.