Zhang Xuemei, Hoff Inge
Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Høgskoleringen 7A, 7491 Trondheim, Norway.
Materials (Basel). 2021 Mar 3;14(5):1174. doi: 10.3390/ma14051174.
The aging of bitumen is detrimental to the durability and service life of asphalt pavement. Previous studies found that bitumen was suspected to be aged by not only thermal oxidation but also solution immersion. This research aims to compare the effect of thermal-oxidative aging and salt solution aging on bitumen performance. For this purpose, a thin film oven test (TFOT) and pressure aging vessel aging (PAV) were selected as thermal-oxidative aging, and 10% NaCl aging and 10% CaCl aging were selected as salt solution aging. The morphology, oxygen content, physical properties, low-temperature properties, and high-temperature properties of bitumen were analysed by employing scanning electron microscopy with an energy dispersive spectrometer (SEM-EDS), physical tests, a bending beam rheometer (BBR), and a dynamic shear rheometer (DSR). Test results show that both thermal-oxidative aging and salt solution aging had similar influencing trends in the oxygen content, physical, low-temperature, and high-temperature properties of bitumen but had different changes in morphology. The aging degrees caused by four kinds of aging methods were obtained based on the summed values of the absolute aging factor of all parameters: PAV > 10% NaCl > TFOT > 10% CaCl. The conclusions could provide a theoretical basis to establish a standard for the solution aging of bitumen.
沥青老化对沥青路面的耐久性和使用寿命有害。以往研究发现，沥青不仅会因热氧化老化，还可能因溶液浸泡而老化。本研究旨在比较热氧化老化和盐溶液老化对沥青性能的影响。为此，选择薄膜烘箱试验（TFOT）和压力老化容器老化（PAV）作为热氧化老化方式，选择10%NaCl老化和10%CaCl老化作为盐溶液老化方式。采用带能谱仪的扫描电子显微镜（SEM-EDS）、物理试验、弯曲梁流变仪（BBR）和动态剪切流变仪（DSR）对沥青的形态、氧含量、物理性能、低温性能和高温性能进行了分析。试验结果表明，热氧化老化和盐溶液老化在沥青的氧含量、物理性能、低温和高温性能方面具有相似的影响趋势，但在形态上有不同变化。基于所有参数绝对老化因子的总和值得到了四种老化方法导致的老化程度：PAV＞10%NaCl＞TFOT＞10%CaCl。这些结论可为建立沥青溶液老化标准提供理论依据。
