This study concerns the frost durability of an ordinary concrete without air-entraining agents. The water—cement ratio and the quantity of cement were chosen within the limitations imposed by the French standard. Physical and mechanical characteristics evolutions during freezing—thawing cycles have been followed. The obtained results show that the reduction in the mechanical resistance and the elastic modulus is accompanied by an increase in the intrinsic permeability. The damage is characterized by a scalar parameter, Df, due to frost action with which the resistance reduction as well as the permeability evolution may be described as a function of crack development. The pore liquid phase pressure, generated during ice formation, was also calculated by an inverse poroelastic analysis based on strains recorded during freezing—thawing cycles. A negative pore pressure of 25 MPa at a temperature of -15° C resulting in an effective stress representing 25% of the compressive strength was found.