The objective of this study was to examine the effect of a needle-punched polyester geotextile on moisture migration and frost heaveduring freezing and thawing in a large test basin. In the past, nonwoven polypropylene geotextiles have been effective in reducing frost heave in laboratory tests. In this case, a needle-punched polyester geotextile separator was monitored for its influence on frost heave and soil moisture tension for four freeze-thaw cycles in a large test basin. Results from freezing tests in the test basin without a water table and with a water table present 12.7 Cm below the fabric suggest that use of the fabric results in greater frost heave. When the water table was above the fabric, the fabric had no influence on frost heave or water distribution in the soil. Laboratory tests indicate that the separator had no effect on frost heave. Tensiometer data in the test basin indicate that lateral transmission of water through the fabric may have occurred, so transmission of water from thawed soil to freezing soil may have contributed to increased frost heave. It is concluded that if a geotextile is used in frost-susceptible soil, proper drainage and the correct fabric type must be used toprevent increased frost heave. The role of geotextile surface properties is important and their influence on moisture migration should be investigated further. This paper appears in transportation research record no. 1307, Pavement analysis, design, rehabilitation, and environmental factors 1991.
Samenvatting