根据21种常规级配,制备Superpave旋转压实试件用以评价沥青混合料的级配离析.利用数字图像处理技术,获得试件截面图像,并根据FeretDiameter提取图像中各档粗集料的颗粒信息.改进了结构各向异性的体视学评价方法,提出使用粗集料结构系数Jf作为评价沥青混合料试件级配离析的指标参数.对各级配的Jf值和各档粗集料分计筛余百分率关系进行了线性回归,其复相关系数R达到0.962 1.对于颗粒最大标称粒径相同的级配,使用灰色关联分析,得出结论:除颗粒最大标称粒径为9.5 mm级配外,Jf受级配中第3大筛孔分计筛余百分率影响最大.
To evaluate the gradational segregation in asphalt mixture,SGC specimens were compacted according to twenty-one usual gradations. The sectional images of specimens were acquired using digital image processing technique. FeretDiameter was used to distinguish the coarse aggregates. The stereological determination technology which was used to evaluate the structure anisotropy was improved in the present work. The coarse aggregate structure factor Jf was used to evaluate the anisotropy of asphalt mixture. Linear regression was made between Jf and subtotal triage of coarse aggregates,and its correlations coefficient reached 0.962 1. To the gradations with the same maximum nominal grain size,grey correlation was used to analyze the results. The conclusion showed that,except the 9.5 mm-maimum-nominal-grain-size gradation,Jf was influenced mostly by the subtotal triage of coarse aggregates in the third large sieve pore.