Zhu Bing, Liu Hanbing, Li Wenjun, Wu Chunli, Chai Chao
College of Transportation, Jilin University, Changchun 130025, China.
Sensors (Basel). 2020 Sep 7;20(18):5090. doi: 10.3390/s20185090.
Acoustic emission (AE), as a nondestructive testing (NDT) and real-time monitoring technique, could characterize the damage evolution and fracture behavior of materials. The primary objective of this paper was to investigate the improvement mechanism of steel slag on the low-temperature fracture behavior of permeable asphalt mixtures (PAM). Firstly, steel slag coarse aggregates were used to replace basalt coarse aggregates with equal volume at different levels (0%, 25%, 50%, 75%, and 100%). Then, the low-temperature splitting test with slow loading was used to obtain steady crack growth, and the crack initiation and propagation of specimens were monitored by AE technique in real time. From the low-temperature splitting test results, SS-100 (permeable asphalt mixtures with 100% steel slag) has the optimal low-temperature cracking resistance. Therefore, the difference of fracture behavior between the control group (permeable asphalt mixtures without steel slag) and SS-100 was mainly discussed. From the AE test results, a slight bottom-up trend of sentinel function was founded in the 0.6-0.9 displacement level for SS-100, which is different from the control group. Furthermore, the fracture stages of the control group and SS-100 could be divided based on cumulative RA and cumulative AF curves. The incorporation of 100% steel slag reduced the shear events and restrained the growth of shear cracking of the specimen in the macro-crack stage. Finally, the considerable drops of three kinds of -values in the final phase were found in the control group, but significant repeated fluctuations in SS-100. In short, the fracture behavior of PAM under low temperature was significantly improved after adding 100% steel slag.
声发射（AE）作为一种无损检测（NDT）和实时监测技术，可以表征材料的损伤演化和断裂行为。本文的主要目的是研究钢渣对透水沥青混合料（PAM）低温断裂行为的改善机制。首先，使用钢渣粗集料以不同水平（0%、25%、50%、75%和100%）等量替代玄武岩粗集料。然后，采用慢速加载的低温劈裂试验来获得稳定的裂纹扩展，并通过声发射技术实时监测试件的裂纹起裂和扩展。从低温劈裂试验结果来看，SS - 100（含100%钢渣的透水沥青混合料）具有最佳的低温抗裂性能。因此，主要讨论了对照组（不含钢渣的透水沥青混合料）与SS - 100之间的断裂行为差异。从声发射试验结果可知，SS - 100在位移水平0.6 - 0.9时哨兵函数呈现轻微的自下而上趋势，这与对照组不同。此外，可根据累积RA曲线和累积AF曲线划分对照组和SS - 100的断裂阶段。掺入100%钢渣减少了剪切事件，并在宏观裂纹阶段抑制了试件剪切裂纹的扩展。最后，发现对照组在最后阶段三种 - 值有显著下降，而SS - 100有明显的重复波动。总之，添加100%钢渣后，透水沥青混合料在低温下的断裂行为得到显著改善。
