Xing Chengwei, Qin Juze, Cheng Zhiqiang, Li Mingchen, Lu Qingbing
Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang'an University, South 2nd Ring Road Middle Section, Xi'an 710064, China.
School of Highway, Chang'an University, South 2nd Ring Road Middle Section, Xi'an 710064, China.
Materials (Basel). 2023 May 23;16(11):3910. doi: 10.3390/ma16113910.
Due to the highly viscous characteristics of high viscosity modified bitumen (HVMB), the commonly used short-term aging schemes are not suitable for it. As such, the objective of this study is to introduce a suitable short-term aging scheme for HVMB by increasing the aging period and temperature. For this purpose, two kinds of commercial HVMB were aged via rolling thin-film oven test (RTFOT) and thin-film oven test (TFOT) at different aging periods and temperatures. At the same time, open-graded friction course (OGFC) mixtures prepared using HVMB were also aged via two aging schemes to simulate the short-term aging of bitumen at the mixing plant. With the aid of temperature sweep, frequency sweep, and multiple stress creep recovery tests, the rheological properties of short-term aged bitumen and the extracted bitumen were tested. By comparing the rheological properties of TFOT- and RTFOT-aged bitumen with those of extracted bitumen, suitable laboratory short-term aging schemes for HVMB were determined. Comparative results showed that aging the OGFC mixture in a 175 °C forced-draft oven for 2 h is suitable to simulate the short-term aging process of bitumen at the mixing plant. Compared with RTOFT, TFOT was more preferable for HVMB. Additionally, the recommended aging period and temperature for TFOT was 5 h and 178 °C, respectively.
由于高粘度改性沥青(HVMB)具有高粘性的特性,常用的短期老化方案并不适用于它。因此,本研究的目的是通过延长老化时间和提高老化温度来引入一种适用于HVMB的短期老化方案。为此,两种商用HVMB在不同的老化时间和温度下通过旋转薄膜烘箱试验(RTFOT)和薄膜烘箱试验(TFOT)进行老化。同时,使用HVMB制备的开级配磨耗层(OGFC)混合料也通过两种老化方案进行老化,以模拟搅拌厂中沥青的短期老化。借助温度扫描、频率扫描和多重应力蠕变恢复试验,对短期老化沥青和萃取沥青的流变性能进行了测试。通过比较TFOT和RTFOT老化沥青与萃取沥青的流变性能,确定了适用于HVMB的实验室短期老化方案。对比结果表明,在175℃的强制通风烘箱中对OGFC混合料进行2小时的老化,适合模拟搅拌厂中沥青的短期老化过程。与RTOFT相比,TFOT对HVMB更适用。此外,TFOT推荐的老化时间和温度分别为5小时和178℃。