基于集料特性的沥青混合料级配设计
Gradation Design of Asphalt Mixture Based on Aggregate Features

多级嵌挤沥青混合料经过多年的工程应用证明了其具有良好的路用性能，但由于当前料源多边形及加工工艺发生很大的变化，对于吸水率偏大密度偏小且棱角性较强的特殊石料，事实证明要想达到理想的混合料体积指标，就需要增加沥青的用量，结合级配设计理论及实践经验，需要对混合料的级配组成进行一定的优化设计。本文借鉴SMA间断级配和林秀贤前辈提出的这段级配理论，对强棱角性集料用于中面层密级配沥青混合料进行了尝试性的级配优化。设计结果证明，对于强棱角性等特殊集料为了保证混合料的骨架结构同时为了确保压实效果，在增加粗骨料和细集料用量的同时减少中间部分骨料，可以达到低沥青用量的同时又保证了混合料的骨架结构和密实性。但是由于粗骨料的用量偏多，在施工过程中需要对混合料的离析现象加以考虑，确保混合料整体的均匀性。
The multi-stage embedded asphalt mixture has been proved to have good road performance after years of engineering application. However, due to the great changes in the current material source polygon and processing technology, for the special stone with high water absorption, small density and strong angularity, it has been proved that in order to achieve the ideal volume index of mixture, it is necessary to increase the amount of asphalt. Combined with the theory and practical ex-perience of gradation design, the gradation composition of mixture should be optimized. Based on SMA discontinuous gradation and the grading theory proposed by Lin Xiuxian, this paper makes a common sense gradation design for dense graded asphalt mixture with strong angular aggregate. The design results show that for special aggregates such as strong angularity, in order to ensure the skeleton structure of the mixture and to ensure the compaction effect, the amount of coarse aggregate and fine aggregate can be increased and the discontinuous gradation of the middle part of aggregate can be reduced, which can ensure the skeleton structure and compactness of the mixture. However, due to the large amount of coarse aggregate, the segregation phenomenon of the mixture should be considered in the construction process to ensure the overall uniformity of the mixture.