Test Analysis on Drainage Base Mixture of Asphalt Pavement in Cold Area

Drainage base can effectively maintain the service performance of asphalt pavement structure in cold and humid areas, and improve its service durability. The void ratio of drainage base asphalt mixture shall be more than 20%, and the asphalt content is generally between 3.15% and 3.55%. Five kinds of open graded asphalt macadam mixtures were selected and tested for structural performance, water permeability, mechanical performance and water temperature stability. According to the test results, it is shown as follows. The water permeability coefficient of the five kinds of asphalt mixtures at 15°C was 0.10-0.19cm/s. The ratio of freeze-thaw splitting strength was 72.1%-92.3%. The compressive strength of uniaxial compression test was 4.53-8.91MPa. The compressive modulus of resilience was 794.79-1236.51MPa. The maximum bending tensile strain of beam was 3150-4977με. It has good structural strength, water stability and drainage performance. After 10-50 freeze-thaw cycles, the performance of structural performance index, tensile strain and mechanical index of asphalt mixture is well. The asphalt mixture can be used for drainage of asphalt pavement structure in high-latitude and low-altitude cold area. The recommended suitable layer is the upper base or lower layer of asphalt pavement structure.