About 24% of the Northern Hemisphere lives with permafrost, which means that the underground remains frozen during at least two years. However, there is always an active layer which thaws in summer. The water is not able to be absorbed by the froozen underground and this induces a swamp unstable underground. The following pictures are a typical example of this unstable underground for buildings and roads.

These instabilities can be solved by using GLAPOR cellular glass gravel like shown in the following schematic drawing. This configuration with about 30 cm gravel avoids that the underground thaws or eliminates the active layer. This system can be used for houses like alreay shown in previous posts but also for roads, like calulated in a paper of the Norwegian government. 

Foamed glass gravel is a light strong material, able to bear the load of a road and insulate the underground from the climate changes. It allows cheaper more stable constructions by recycling waste glass.