Experimental Study on Frost-Heave Mitigation in Subgrade Treated with Organosilane-Based Spray Applications

Abstract: Frost heave remains a critical challenge in cold-region pavements, often resulting in surface roughness, cracking, and accelerated deterioration. Conventional mitigation methods, such as insulation layers or replacement of frost-susceptible soils, are effective but can be costly and difficult to implement at scale.
This study aims to evaluate the effectiveness of an organosilane-based water-repellent treatment (Terrasil), applied through spraying, in mitigating frost heave in a frost-susceptible subgrade soil. Five laboratory frost-heave experiments were conducted: two untreated controls (one under an open water supply and one under a closed condition) and three treated specimens sprayed with Terrasil at different concentrations and application rates, all subjected to open water supply. The objective was to assess the water-repellent treatment as a barrier against moisture migration and frost action. Performance was evaluated in terms of heave magnitude, water intake, and post-test moisture distribution, with comparisons drawn against the untreated controls.
The laboratory findings confirm that organosilane treatment significantly reduces frost heave in pavement subgrades. Treated specimens exhibited up to 88% less heave and nearly 90% lower water uptake than untreated soils, demonstrating a clear reduction in cryosuction-driven moisture migration. In addition, a noticeable delay in frost-heave development was observed in treated soils, indicating reduced susceptibility to ice lens formation due to lower moisture availability. These results highlight organosilane spraying as a practical and sustainable approach to frost-heave mitigation, with the potential to extend pavement service life, reduce maintenance costs, and enhance performance in cold-region infrastructure.