Ye Yangsheng, Xu Gang, Lou Liangwei, Chen Xianhua, Cai Degou, Shi Yuefeng
Railway Engineering Research Institute, China Academy of Railway Sciences Corporation Limited, Beijing 100081, China.
School of Transportation, Southeast University, Nanjing 211189, China.
Materials (Basel). 2019 Jul 24;12(15):2345. doi: 10.3390/ma12152345.
In this study, a new type of composite modified bitumen was developed by blending styrene-butadiene-styrene (SBS) and crumb rubber (CR) with a chemical method to satisfy the durability requirements of waterproofing material in the waterproofing layer of high-speed railway subgrade. A pressure-aging-vessel test for 20, 40 and 80 h were conducted to obtain bitumen samples in different long-term aging conditions. Multiple stress creep recovery (MSCR) tests, linear amplitude scanning tests and bending beam rheometer tests were conducted on three kinds of asphalt binders (SBS modified asphalt, CR modified asphalt and SBS/CR composite modified asphalt) after different long-term aging processes, including high temperature permanent deformation performance, resistance to low temperature thermal and fatigue crack. Meanwhile, aging sensitivities were compared by different rheological indices. Results showed that SBS/CR composite modified asphalt possessed the best properties before and after aging. The elastic property of CR in SBS/CR composite modified asphalt improved the ability to resist low temperature thermal and fatigue cracks at a range of low and middle temperatures. Simultaneously, the copolymer network of SBS and CR significantly improved the elastic response of the asphalt SBS/CR modified asphalt at a range of high temperatures. Furthermore, all test results indicated that the SBS/CR modified asphalt possesses the outstanding ability to anti-aging. SBS/CR is an ideal kind of asphalt to satisfy the demand of 60 years of service life in the subgrade of high speed railway.
在本研究中，通过化学方法将苯乙烯-丁二烯-苯乙烯（SBS）和胶粉（CR）共混，开发出一种新型复合改性沥青，以满足高速铁路路基防水层中防水材料的耐久性要求。进行了20、40和80小时的压力老化试验，以获得不同长期老化条件下的沥青样品。对三种沥青结合料（SBS改性沥青、CR改性沥青和SBS/CR复合改性沥青）在不同长期老化过程后进行了多重应力蠕变恢复（MSCR）试验、线性振幅扫描试验和弯曲梁流变仪试验，包括高温永久变形性能、抗低温热裂和疲劳开裂性能。同时，通过不同的流变指标比较老化敏感性。结果表明，SBS/CR复合改性沥青在老化前后具有最佳性能。SBS/CR复合改性沥青中CR的弹性性能提高了其在中低温范围内抵抗低温热裂和疲劳开裂的能力。同时，SBS和CR的共聚物网络显著提高了SBS/CR改性沥青在高温范围内的弹性响应。此外，所有试验结果表明，SBS/CR改性沥青具有优异的抗老化能力。SBS/CR是一种理想的沥青，能够满足高速铁路路基60年使用寿命要求。
