Seasonal freeze-thaw cycles in cold regions are a key factor leading to pavement damage. The duration and penetration depth of freeze-thaw cycles in the foundation layers can significantly influence the pavement performance. Frost heaves and loss of support conditions are two direct results due to pavement freezing and thawing. Current research has brought great interests in this topic, which may benefit pavement design, construction, and maintenance.

Sufficient freezing depth, continuous water supply, and frost susceptible geomaterials are the three factors required resulting in pavement freeze-thaw related damage. When these factors are satisfied, stiffness and support conditions can be significantly affected due to the phase change of moisture within pavement structures. In various current pavement design guides, seasonal variation in foundation layers is taken into consideration by empirically adjusting the foundation layer moduli values. As various QC/QA testing methods is used in practice, different mechanistic properties can be derived. Even though only a few particular parameters are considered in current pavement design guides, empirical correlations were reported for transferring different properties. Values of these measurable properties change seasonally, which may differ from the values of design parameters after correlations. Therefore, it is necessary to evaluate if the seasonal mechanistic property values meet the design values and if the empirical correlations match to the in situ measurements.

This study focused on investigating the frost actions of pavement foundations that may affect pavement designs, such as frost penetration depths, number of freeze-thaw cycles, moisture conditions, and geomaterial frost susceptibility. QC/QA tests were conducted to assess the influences and performance on reconstructed and rehabilitated pavement foundation stiffness and support conditions. Seasonal strength/stiffness results of pavement foundation layers were evaluated in comparison with design values in terms of empirical correlations.