Xu Huining, Li Hengzhen, Tan Yiqiu, Wang Linbing, Hou Yue
School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
Department of Civil Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
Entropy (Basel). 2018 Jan 23;20(2):68. doi: 10.3390/e20020068.
The thermodynamic behavior of asphalt mixtures is critical to the engineers since it directly relates to the damage in asphalt mixtures. However, most of the current research of the freeze-thaw damage of asphalt mixtures is focused on the bulk body from the macroscale and lacks a fundamental understanding of the thermodynamic behaviors of asphalt mixtures from the microscale perspective. In this paper, to identify the important thermodynamic behaviors of asphalt mixtures under freeze-thaw loading cycle, the information entropy theory, an X-ray computerized tomography (CT) scanner and digital image processing technology are employed. The voids, the average size of the voids, the connected porosity, and the void number are extracted according to the scanned images. Based on the experiments and the CT scanned images, the information entropy evolution of the asphalt mixtures under different freeze-thaw cycles is calculated and the relationship between the change of information entropy and the pore structure characteristics is established. Then, the influences of different freezing and thawing conditions on the thermodynamic behaviors of asphalt mixtures are compared. The combination of information entropy theory and CT scanning technique proposed in this paper provides an innovative approach to investigate the thermodynamics behaviors of asphalt mixtures and a new way to analyze the freeze-thaw damage in asphalt mixtures.
沥青混合料的热力学行为对工程师而言至关重要，因为它直接关系到沥青混合料的损伤情况。然而，目前大多数关于沥青混合料冻融损伤的研究都集中在宏观尺度上的整体，缺乏从微观尺度角度对沥青混合料热力学行为的基本理解。本文采用信息熵理论、X射线计算机断层扫描（CT）扫描仪和数字图像处理技术，以识别沥青混合料在冻融加载循环下的重要热力学行为。根据扫描图像提取孔隙、孔隙平均尺寸、连通孔隙率和孔隙数量。基于实验和CT扫描图像，计算了不同冻融循环次数下沥青混合料的信息熵演化，并建立了信息熵变化与孔隙结构特征之间的关系。然后，比较了不同冻融条件对沥青混合料热力学行为的影响。本文提出的信息熵理论与CT扫描技术相结合，为研究沥青混合料的热力学行为提供了一种创新方法，也为分析沥青混合料的冻融损伤提供了一种新途径。
