In areas where frost is common, with soils that are vulnerable to frost conditions and the associated water input problem, simple roads are particularly exposed to frost damage (ice formation). Frost-sensitive soils fall into two main categories:
1. silty soils, where frost causes lifting and thawing causes a loss of bearing capacity;
2. clay soils, where thawing results in a loss of bearing capacity.
Under normal conditions, a road with the proper dimensions will not suffer from frost. In gravelly or sandy soils, frost will not be a problem as long as the drainage is good. In the case of roads in Alpine regions that are not kept clear of snow, the snow acts as an insulator and no frost-related problems arise.
In the case of most soils, except extreme silt or very fine sand (Ip < 12, where Ip = plasticity index), building for bearing capacity will suffice (e.g., as per American Association of State Highway Officials (AASHO)).
Was this article helpful?