Zhang Ke, Wei Guangliang, Xie Wei, Yang Baocheng, Li Wenlong, Luo Yaofei
College of Information Engineering, Fuyang Normal University, Fuyang 236041, China.
School of Civil Architecture, Anhui University of Science & Technology, Huainan 232001, China.
Materials (Basel). 2022 Oct 18;15(20):7284. doi: 10.3390/ma15207284.
To effectively evaluate the construction homogeneity of asphalt pavement, the tomography image of a core sample of asphalt pavement was obtained via industrial computed tomography (CT) equipment. According to the characteristics of CT images, an improved separation algorithm based on annular partition and Nobuyuki Otsu (OTSU) threshold segmentation was proposed. Based on the distribution of aggregates, voids and asphalt mortar, and the area ratio of each part in the CT images inside the pavement, a novel evaluation method for the distribution homogeneity of asphalt pavement components was put forward, and the validity of the evaluation index was also verified. The results show that the aggregates, voids and asphalt mortar in CT images can be effectively segmented by annular partition combined with the OTSU threshold separation algorithm. By superimposing the segmented image on the original image, the segmentation and identification effects of aggregates, voids and asphalt mortar in the CT image are confirmed. Compared with a non-segregated specimen, the average values of the horizontal heterogeneity coefficients of high, medium, light and fine-aggregate-segregated mixtures increased by 72.0%, 48.3%, 34.7% and 16.1%, respectively, where the change range is in accordance with the segregation degrees of several mixtures. The indirect tensile strength of fine-aggregate-, light-, medium- and high-segregated asphalt mixtures decreased by 8.3%, 16.7%, 25.0% and 45.8%, respectively, when compared with the non-segregated asphalt mixture. The index of the vertical heterogeneity coefficient has good correlation with the indirect tensile strength of segregated asphalt mixtures. The construction quality homogeneity of asphalt pavement in different regions can be reliably evaluated by the horizontal heterogeneity coefficient and vertical heterogeneity coefficient.
为有效评价沥青路面的施工均匀性，利用工业计算机断层扫描（CT）设备获取了沥青路面芯样的断层图像。根据CT图像的特点，提出了一种基于环形分区和大津（OTSU）阈值分割的改进分离算法。基于集料、空隙和沥青胶浆的分布以及路面内部CT图像中各部分的面积比，提出了一种新的沥青路面组分分布均匀性评价方法，并验证了评价指标的有效性。结果表明，采用环形分区结合OTSU阈值分离算法能够有效分割CT图像中的集料、空隙和沥青胶浆。将分割后的图像叠加在原始图像上，证实了CT图像中集料、空隙和沥青胶浆的分割与识别效果。与未离析试件相比，高、中、轻、细集料离析混合料的水平不均匀系数平均值分别提高了72.0%、48.3%、34.7%和16.1%，其变化幅度与几种混合料的离析程度一致。与未离析的沥青混合料相比，细集料、轻、中、高离析沥青混合料的间接拉伸强度分别降低了8.3%、16.7%、25.0%和45.8%。垂直不均匀系数指标与离析沥青混合料的间接拉伸强度具有良好的相关性。利用水平不均匀系数和垂直不均匀系数能够可靠地评价不同区域沥青路面的施工质量均匀性。
