为研究旋转压实的压力参数对大粒径沥青碎石破碎程度影响,选择五种不同竖向压力对三种不同沥青含量的ATB30进行旋转压实试验,对试样进行抽提、筛分,获得粒径分布资料。试验结果表明:集料破碎后的粒径分布均有良好的分形特征,分形维数值在2.4787~2.6260之间;破碎后颗粒增量变化总体特征为,先增加后减小,最后趋于稳定的变化趋势;4.75~9.5mm和16~19mm区间的颗粒有利于抵抗外部荷载,保持骨架密实结构,可以用贝雷法进行验证;破碎分形维数越大,集料破碎量越大,并与Hardin破碎率接近线性关系;集料破碎分形维数随竖向压力增加而呈现先减小后增大规律;沥青含量对分形维数的影响小;采用分形维数可以对沥青混合料的级配进行优化、。
In order to study the effect of pressure parameters of rotating compaction on large size asphalt macadam broken degree, the gyratory compaction test on ATB30 with 3 kinds of asphalt content is carried out under 5 vertical pressures, and the particle size distribution data is obtained after extraction and screening on test specimens. The test result shows that ( 1 ) the particle size distribution of crushed aggregate has good fractal characteristics, the fraetal dimension is between 2. 478 7 and 2. 626 0; (2) the characteristics of crushed particle increment increases at first and then decreases, finally tends to be stable; (3) the particles whose size in the ranges of 4. 75 - 9.5 mm and 16 - 19 mm are good for resisting external loads, keeping dense skeleton structure, which can be verified by Bailey method ; (3) the greater the fractal dimension, the larger the amount of aggregate crushing, and it shows a liner relationship with the Hardin crushing ratio ; (4) with the increase of vertical pressure, the fraetal dimension of aggregate crushing decreases firstly and then increases; (5) asphalt content has little effect on the fractal dimension; (6) dimension can be used to optimize the particle gradation of asphalt mixture.