The stability of surface infrastructure founded on permafrost can have a significant impact to the safety and reliability of the infrastructure systems and lead to unexpected maintenance costs over the life of the asset. In most cases, the surface infrastructure (roads, working pads, dams, water containment ponds and diversions) alters the surface energy balance and the amount of heat being transferred to and from the ground. Consequently, the greater input of heat to the ground often causes permafrost warming and thaw that impacts foundation stability. Climate change adds an additional level of uncertainty to infrastructure performance.
This concept-level study evaluates the use of manufactured phase change materials (PCMs) to control both heat storage and transfer that would otherwise contribute to permafrost thaw beneath the highway embankment and instability of the foundation. PCMs are materials that have a high capacity to store thermal energy. Commercially available PCMs on the market are currently used by various industries and range in applications, including integration of the material into athletic clothing to regulate body temperature, shipping containers for cold storage of food, and building materials to control heating and cooling in homes. A number of PCMs are certified as being environmentally safe and biodegradable.
This concept study is the first step toward evaluating the potential use of these products for highway applications, and further analysis related to thermal performance, cost, constructability, stability, and environmental aspects are warranted.
