The effects of the freeze-thaw cycle on the mechanical properties of the asphalt mixture

Through a comparative analysis of the mechanical properties of asphalt mixture affected by freeze-thaw cycles, the effects of the freeze-thaw cycles on the mechanical properties of the asphalt mixture were investigated. The change laws of high temperature performance, strength, the modulus and fatigue performance of the asphalt mixture after the freeze-thaw cycles were analyzed, and the characteristics of the damage were also determined. The investigation shows that the creep rate of the asphalt mixture increases at a stable creep stage after the freeze-thaw cycles, and the freeze-thaw cycles magnify the effects of the high temperature stability of the asphalt mixture on the sensitivity of the stress level. Meanwhile, with the increase of the number of freeze-thaw cycles, the compressive strength and rebound modulus of the asphalt mixture decrease, and the variation of the damage variable was divided into three stages, i.e., fast damage period, stable damage period and damage development period. The fatigue performance of the asphalt mixture is reduced, and the fatigue life is more sensitive to the variation of stress levels after the asphalt is suffered by the freeze-thaw cycles.