Yu Di, Jing Haosen, Liu Jianan
School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang 330013, China.
College of Transportation, Jilin University, Changchun 130025, China.
Materials (Basel). 2022 May 16;15(10):3560. doi: 10.3390/ma15103560.
Freeze-thaw cycle is one of the main distresses of asphalt pavement, and the law of freeze-thaw damage has always been an important topic. In this paper, X-ray computed tomography (CT) of asphalt mixture before and after freezing and thawing was carried out, and its two-dimensional (2D) digital image was recognized. Firstly, the eigenvalues of internal voids of asphalt mixture are extracted. Then the distribution of internal voids was analyzed. Finally, the evolution law of internal voids was summarized. The research results show that the characteristic mean value of the 9th cycle is the irreversible limit of freeze-thaw damage, and the non-resilience after the large void area increases is the fundamental reason for the accumulation of freeze-thaw damage. The source of void damage shifts from large voids to small voids, and the middle-stage is a critical stage of freeze-thaw damage. This work quantitatively evaluates the internal freeze-thaw damage process of asphalt mixture, and a morphological theory of the evolution of void damage based on an equivalent ellipse is proposed, which is helpful for better understanding the freezing-thawing damage law of asphalt pavement.
冻融循环是沥青路面的主要病害之一，冻融破坏规律一直是一个重要课题。本文对沥青混合料冻融前后进行了X射线计算机断层扫描（CT），并识别了其二维（2D）数字图像。首先，提取沥青混合料内部空隙的特征值。然后分析内部空隙的分布。最后总结内部空隙的演化规律。研究结果表明，第9次循环的特征均值是冻融破坏的不可逆极限，大空隙面积增加后的非弹性恢复是冻融破坏累积的根本原因。空隙破坏源从大空隙向小空隙转移，中间阶段是冻融破坏的关键阶段。本研究定量评估了沥青混合料内部冻融破坏过程，提出了基于等效椭圆的空隙破坏演化形态学理论，有助于更好地理解沥青路面的冻融破坏规律。
