Subsequently to serious pavement disorders appearing suddenly during winters and characterized by series of potholes, CEREMA and IFSTTAR launched an experimental program to understand the mechanisms at play and possibly provide technical recommendations for the future. Based on in-situ observations showing the concomitance of frost/thaw cycles and wet conditions during these events, the study focused on the impact of frost propagation on the behavior of asphalt mixes partially saturated with water. Cyclic thermal tests performed free of external loading (except the own weight of the samples) show significant swelling and contraction of the samples because of the phase changes of pore water from liquid to solid and vice versa. Additional tests intended to the measurement of the complex modulus of bituminous mixes also show evidence of a frost effect on wet samples, characterized by the stiffening of the material. These effects could be at the origin of the disorders under consideration. Further work should help validate this hypothesis and find remedies to the problem.