Resilient modulus (Mr) and permanent deformation (PD) characteristics of unbound aggregates under repetitive traffic loads dictate the structural response and performance of pavement base and subbase layers. Aggregate material behavior is dependent on the amount of fines in particulate matrix, also referred to as fines content (percent passing number 200 sieve), as well as plasticity index, dust ratio (percent passing number 200 sieve to percent passing number 40 sieve), material type, aggregate gradation/packing and the interactions of these properties with each other. In this study, repeated load triaxial tests were conducted on crushed limestone and crushed gravel aggregates. Fines content and plasticity index were varied from 5% to 12% and 5% to 9%, respectively. Two most typical gradations of aggregates used in roadway construction in Illinois were utilized with dust ratios ranging from 0.4 to 1.0. The results of these tests were analyzed using the shakedown theory for evaluating typical base/subbase permanent deformation or rutting trends linked to practical design considerations. Charts were also established for the modulus and deformation characteristics of unbound aggregates to designate the material quality with performance trends. Such guiding charts were compared with others developed in previous studies by authors for determining aggregate behavior under monotonic loading tests such as California Bearing Ratio (CBR). The comparisons provide valuable insights on how each aggregate property influences strength, modulus and permanent deformation behavior under different loading conditions.

在重复交通荷载下，未结合集料的弹性模量 (Mr) 和永久变形 (PD) 特性决定了路面基层和底基层的结构响应和性能。骨料的行为取决于颗粒基质中细粉的数量，也称为细粉含量（通过 200 筛的百分比），以及可塑性指数、粉尘比（通过 200 筛的百分比与通过 40 筛的百分比），材料类型、骨料级配/堆积以及这些特性之间的相互作用。在这项研究中，对碎石灰石和碎石骨料进行了重复载荷三轴试验。细粉含量和塑性指数分别从 5% 到 12% 和 5% 到 9% 不等。伊利诺伊州道路建设中使用的两种最典型的骨料级配被利用，粉尘比范围为 0.4 到 1.0。这些测试的结果使用稳定理论进行分析，以评估与实际设计考虑相关的典型基础/底基层永久变形或车辙趋势。还建立了未结合骨料的模量和变形特性的图表，以指定具有性能趋势的材料质量。此类指导图表与作者之前研究中开发的其他图表进行了比较，以确定在单调载荷试验（如加利福尼亚承载比 (CBR)）下的聚集行为。这些比较提供了关于每种骨料属性如何影响不同加载条件下的强度、模量和永久变形行为的宝贵见解。