基于CT扫描技术的不同压实度下沥青混合料细观空隙特性研究

Investigation on mesoscopic pore characteristics in asphalt mixtures under varied compaction levels based on CT technology

【目的】深入了解压实不足对沥青混合料内部空隙细观结构的影响。【方法】以SMA-13试件为对象,通过调整压实次数制备不同压实度的试件。采用计算机断层扫描和图像识别技术精确识别空隙,探究不同压实度下的沥青混合料空隙细观结构特性,包括空隙数量、体积、主轴方向角和配位数。【结果】在沥青混合料成型过程中,受到外部击实功的影响,内部空隙的主轴方向逐渐趋向于稳定状态。此外,随着压实次数的增加,沥青混合料内的大部分空隙逐渐减小,但也存在一些相邻的开口空隙在逐渐结合后形成更大的开口空隙。最终,随着压实程度的提高,空隙的平均配位数减小,导致空隙连通性下降,整体空隙网络的复杂度逐渐减小。【结论】本研究旨在更好地理解不同压实度下沥青混合料空隙结构的细观差异,为沥青混合料的设计、评价和维护提供更为科学的依据。

[Purposes]This study aims to delve into the profound impact of insufficient compaction on the mesoscopic structure of pores within asphalt mixtures.[Methods]The exploration of asphalt mixture pore mesostructural features under different compaction levels includes the analysis of pore quantity,volume,spindle orientation,and coordination numbers.[Findings]Throughout the asphalt mixture formation process,the principal axes of internal voids gradually stabilize under the influence of external compaction forces.Additionally,with an increase in compaction cycles,the majority of voids within the asphalt mixture diminish in size.However,some adjacent open voids gradually coalesce,forming larger open voids.Ultimately,as compaction intensity rises,the average coordination number of voids decreases,leading to a reduction in void connectivity and a gradual simplification of the overall void network complexity.[Conclusions]This research endeavors to enhance the comprehension of the mesoscopic variations in pore structures within asphalt mixtures under different compaction levels,offering a more scientifically grounded basis for the design,evaluation,and maintenance of asphalt mixtures.