Particle breakage usually alters the size and shape of ballast aggregates, which significantly influences the long-term performance of rail tracks. This study reports an investigation on the breakage and shape characteristics of ballast aggregates subjected to monotonic and cyclic triaxial tests with two different load frequencies. The results show that particle breakage is not only influenced by the particle size distribution but also by the relative density. Breakage indices defined by breakage potential and grading entropy fail to characterize the breakage extent of ballast with multiple initial particle size distributions, while the Marsal breakage index exhibits a general decrease with increasing coefficient of uniformity for ballast with similar relative densities. Higher breakage extent is observed in ballast subjected to a higher load frequency. Particle shape varies with load frequency because of breakage. A slightly higher value of each shape index is observed for ballast subjected to a higher load frequency, implying that ballast aggregates become increasingly regular with the increase of load frequency.

颗粒破损通常会改变道aggregate骨料的尺寸和形状，从而严重影响轨道的长期性能。这项研究报告了对压载骨料的破碎和形状特征的研究，该压载骨料在两个不同的载荷频率下经受了单调和循环三轴试验。结果表明，颗粒破碎不仅受粒径分布的影响，而且还受到相对密度的影响。由破损电位和分级熵定义的破损指数无法表征具有多个初始粒径分布的压载物的破损程度，而Marsal破损指数随着相对密度相似的压载物的均匀性系数的增加而呈现出总体下降的趋势。在承受较高负载频率的镇流器中观察到较高的破损程度。由于破裂，颗粒形状随负载频率而变化。对于负载频率较高的压载物，每个形状指数的值略高，这意味着压载物骨料随着负载频率的增加而变得越来越规则。