Reducing Soil Strength Variation Due to Frost Action

Frost action, a destructive combination of heaving and thawing, is responsible for more than 60 % of pavement distresses in temperate regions. The effect of frost action can be curtailed through soil moisture control, which is possible through Engineered Water Repellency. This treatment reduces water infiltration, theoretically making the soil less susceptible to strength variations experienced by natural soils during freeze-thaw cycles. For EWR application, two different frost-susceptible soils were treated with a commercial-grade organosilane, Terrasil, then cured for 16 hours and then exposed to wet-dry to mirror moisture variation experienced during freeze-thaw and capillary rise. UCS testing was used for strength determination at a 1 %/min strain rate. USC evaluation was performed on unmodified FSS at varying moisture content to compare. All EWR samples absorbed minimal water, less than 4 g per cycle, and experienced only a 60 % drop in unconfined compressive strength after 12 cycles. In contrast, untreated samples suffered drastic strength fluctuations of up to 260 % due to moisture variations. The study highlights the potential of EWR as an effective method to mitigate soil moisture content variations caused by frost action. This emerging geotechnical engineering solution may offer a sustainable and cost-effective means of preventing load restrictions currently imposed by various DOTs.