不同加载方式下沥青混合料的压实过程与集料运动特性研究

COMPACTION PROCESS AND AGGREGATE MOTION CHARACTERISTICS OF ASPHALT MIXTURES UNDER DIFFERENT LOADING METHODS

  • 摘要: 为探究不同加载方式下沥青混合料的压实过程与集料运动特性,利用智能骨料进行静态压实和旋转压实试验测试;同时采用三维激光扫描设备以及图像处理技术构建具有真实形态特征的粗集料,建立沥青混合料压实过程的离散元模型,并借助智能骨料测试结果对模型进行准确性验证;最后,分析了沥青混合料内部集料运动和接触状况。结果表明,均匀增长的竖向压实载荷无法有效地使颗粒沿水平方向运动,在持续性的竖向载荷以及周期性的揉搓作用下,颗粒水平方向上的迁移和旋转能力得到激发,最终实现材料的致密化;在均匀增长的竖向压实载荷下,试件骨料-骨料间接触力较大,周期性的揉搓作用减轻了试件高压实阻力的形成,使其在后期获得更好的压实效果;靠近载荷作用区域的颗粒所受的运动更加激烈,主动压实区的颗粒运动活跃度大于被动压实区,而边缘区域的颗粒运动变异系数较高。

     

    Abstract: To investigate the compaction process and aggregate movement characteristics of asphalt mixtures under different loading methods, static compaction and rotary compaction experimental tests are conducted using smart rock. At the same time, 3D laser scanning equipment and image processing technology are used to construct coarse aggregates with real morphological characteristics, and a discrete element model of the compaction process of asphalt mixtures is established, the accuracy of the model is verified with the help of smart rock test results. Finally, the aggregate movement and contact conditions inside the asphalt mixture are analyzed. The results show that: the uniformly growing vertical compaction load could not effectively make the particles move along the horizontal direction, and under the continuous vertical load as well as the cyclic kneading effect, the displacement and rotational ability of the particles in the horizontal direction are stimulated, and the densification of the material is finally achieved; the aggregate-aggregate contact force of the test specimen is larger under the uniformly growing vertical compaction load, and the cyclic kneading effect mitigated the resistance to high compaction in the test specimen. The formation of the compaction resistance of the specimen is reduced by the periodic kneading action, which leads to a better compaction effect in the later stage; the particles close to the loaded area are subjected to more intense motion, the active compaction zone is more active than the passive compaction zone, and the coefficient of variation of the particles' motion in the edge area is higher.

     

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