粗集料对沥青混合料空隙结构影响分析

Analysis of the Void Structure Characteristics Affected by Coarse Aggregate in Asphalt Concrete

摘要: 沥青混合料的空隙率与性能密切相关，空隙细观结构直接影响着沥青混合料的各种性能。针对粗集料，设计不同级配和针片状含量的混合料，通过CT扫描、数字图像获取技术方法的研究，获得三维重构图，采用VG Studio MAX2.2设定不同灰度范围，进而提取空隙，构建沥青混合料的空隙空间变化特征图，分析空隙结构评价指标，进而对空隙结构进行研究。通过空隙定性对比发现，该方法获得的空隙变化同表干法实测规律一致；空隙粒径分布受粗集料级配和针片状含量影响显著；通过设定灰度阈值的方法计算沥青混合料空隙率，其结果大于实测空隙率；构建的面积比值参数，能准确地表征沥青混合料中粗集料和空隙的比例关系。

Abstract: Porosity and performance of asphalt mixture are closely related to the microstructure of the gap which directly affects the various properties of asphalt mixture. For the coarse aggregate, the design of different gradation and needle-like content of the mixture, through CT scanning, digital image acquisition technology research, obtained three-dimensional reconstruction diagram. Using VG Studio MAX2.2, it sets a different gray range, and then extracts the gap. The voids of the asphalt mixture were analyzed, and the evaluation index of the void structure was analyzed, after that, the void structure was studied. It is found that the void dates obtained by this method are consistent with standard test. The pore size distribution is affected by the coarse aggregate gradation and the needle sheet content. The asphalt mixture is calculated by setting the gray threshold method Porosity; the result is greater than the measured porosity; the area ratio parameter Q, can accurately characterize the asphalt mixture in the coarse aggregate and the proportion of the gap.