Background
In cold climates, phase changes of water-to-ice and ice-to-water in the pore structures of soils significantly challenge the integrity and longevity of infrastructure. Soils in these regions typically undergo substantial volumetric changes because of climate stressors, impacting structures including building foundations, bridges, pipelines, railways, dams, and pavement subgrades.
Frost action, characterized by seasonal cyclic freezing and thawing of water in soil, profoundly impacts the engineering properties of soil, affecting both mechanical strength and stability through processes such as frost heave and thaw weakening. The most commonly used technique to mitigate frost-action effects is to replace problematic geomaterial or frost-susceptible soil with coarse aggregate such as gravel. However, this method can be expensive depending on the location, the length of the problematic site, and access to suitable coarse aggregate.
Invention Description
Researchers at Arizona State University have developed ICE-Bind, which is a method of creating biogenic carbon-coated, oil-treated plastic granules that lower the freezing point in vulnerable geomaterials. This approach draws from ice-binding proteins (IBPs) found in polar organisms, utilizing surface science principles to create these plastic granules that can lower the freezing point in vulnerable geomaterials. In initial tests, these granules can effectively mimic the function of IBPs by disrupting ice nucleation and growth through interactions among its functional groups, water, and the siliceous substrate. This approach aims to enhance the resilience of geomaterials in cold climates, while repurposing waste materials for sustainable use.
Potential Applications:
- Soil stabilization (e.g., construction, mechanical structures)
- Carbon storage
- Resource conservation & recycling
Benefits and Advantages:
- Reduces adverse effects – lowers freezing point & increases thawing point of treated soils
- Suppresses ice crystallization – disturbs the alignment of water at the surface
- Boosts durability & structural integrity of construction materials – limits the formation and growth of ice within the material matrix