Mineral Gradation Optimization Design Methods Based on Mechanical Indexes
The characteristics of climatic factors in cold regions lead to the difference in the structural evolution mechanism of asphalt mixtures under freeze-thaw cycles in different seasons from other areas.The gradation range of asphalt mixtures in China's current specification applies to domestic regions,however,it is not well targeted.Based on that,this paper designs a targeted gradation of asphalt mixtures and studies the commonly used mixtures,AC-20 and AC-16,and two types of less-experienced mixtures,SMA-13 and ATB-25.By simulating the climatic environment of the cold region to improve the traditional volumetric method,the gradation suitable for the cold region is proposed,and a set of gradation design methods for asphalt mixtures is summarized.The results show that the road performance of the asphalt mixture designed by the new gradation design method is significantly optimized compared with the asphalt mixture with the original gradation.