Song Liang, Yun Di, Ye Wei, Gao Jie
School of Traffic and Transportation Engineering, Xinjiang University, Urumqi 830017, China.
Xinjiang Transportation Investment Construction Management Co., Ltd., Urumqi 830099, China.
Materials (Basel). 2024 Sep 23;17(18):4658. doi: 10.3390/ma17184658.
An Open-Graded Friction Course (OGFC) presents a rough surface and a porous structure and provides skid resistance under wet conditions, differing from that of a dense graded mixture. This study explored the distribution of surface macrotexture with depth in OGFC. Using cross-sectional images and semantic image segmentation techniques, the internal structure, porosity, and void size distribution were analyzed to assess the effectiveness of rainfall drainage. Skid resistance was evaluated with a British Pendulum Tester, focusing on the influence of surface macrotexture and internal macrostructure, particularly with regard to contact depth. Results show that finer gradations increase surface roughness peaks, which are concentrated near the top surface. In contrast, coarser mixtures exhibit a greater effective contact depth and more peaks with higher curvature. Finer gradations also result in lower porosity, greater void dispersion, and smaller average void diameters. During heavy rainfall, OGFC-13 exhibits the highest friction coefficient due to its effective contact, surface roughness, and internal voids, which facilitate water expulsion. This research provides insights into the skid resistance mechanism of OGFC in wet conditions and offers practical guidance for selecting the optimal gradation.
开级配沥青磨耗层（OGFC）具有粗糙的表面和多孔结构，在潮湿条件下提供防滑性能，与密级配混合料不同。本研究探讨了OGFC表面宏观纹理随深度的分布。使用横截面图像和语义图像分割技术，分析了内部结构、孔隙率和空隙尺寸分布，以评估降雨排水的有效性。使用英国摆式摩擦系数测试仪评估防滑性能，重点关注表面宏观纹理和内部宏观结构的影响，特别是接触深度方面的影响。结果表明，较细的级配增加了表面粗糙度峰值，这些峰值集中在顶面附近。相比之下，较粗的混合料具有更大的有效接触深度和更多曲率更高的峰值。较细的级配还会导致孔隙率降低、空隙分散性更大且平均空隙直径更小。在暴雨期间，OGFC - 13由于其有效的接触、表面粗糙度和内部空隙而表现出最高的摩擦系数，这些因素有助于排水。本研究深入了解了OGFC在潮湿条件下的防滑机理，并为选择最佳级配提供了实际指导。
