Zieliński Piotr, Klimczak Marek, Tekieli Marcin, Strzępek Mateusz
Faculty of Civil Engineering, Cracow University of Technology, 31-155 Cracow, Poland.
Materials (Basel). 2025 Feb 21;18(5):967. doi: 10.3390/ma18050967.
The semi-circular bending method (SCB) is a useful test for evaluating the cracking resistance of asphalt mixtures with added reclaimed asphalt shingles. A mixture of the asphalt concrete AC 16 with 50/70 paving bitumen was used for the binder course test as a reference mix. The purpose of the paper is to evaluate two aging conditions (short-term and long-term) of the above-mentioned asphalt mixtures in relation to their fracture properties. Laboratory experiments are enhanced with the application of image processing techniques (digital image correlation and image segmentation) that account for the asphalt mixture heterogeneity. Consequently, they can provide a more detailed description of the specimen performance. Statistical analyses of the laboratory results indicate that the best sensitivity in terms of differentiating the tested mixtures, especially taking into account the aging conditions of the mixtures, was observed for the post-peak parameters such as the flexibility index (FI), toughness index (TI), and, above all, cracking resistance index (CRI), for which the average coefficient of the result variability is approximately 10%, while for the FI and TI parameters it is approximately 30%. Digital image correlation analyses provided a confirmative illustration of the aforementioned observation.
半圆弯曲试验方法（SCB）是评估添加再生沥青瓦的沥青混合料抗裂性的一种有效试验。以一种采用50/70道路石油沥青的AC 16沥青混凝土混合料作为粘结层试验的参考混合料。本文的目的是评估上述沥青混合料在两种老化条件（短期和长期）下的断裂性能。通过应用图像处理技术（数字图像相关和图像分割）增强了实验室试验，这些技术考虑了沥青混合料的非均质性。因此，它们可以更详细地描述试件性能。实验室结果的统计分析表明，对于峰后参数，如柔性指数（FI）、韧性指数（TI），尤其是抗裂指数（CRI），在区分测试混合料方面具有最佳敏感性，尤其是考虑到混合料的老化条件时，其结果变异性的平均系数约为10%，而对于FI和TI参数，该系数约为30%。数字图像相关分析为上述观察结果提供了确凿的例证。
