论文部分内容阅读
为考察在融雪盐环境下路面材料的性能变化情况,对内蒙古寒冷地区常用的SBS(苯乙烯-丁二烯-苯乙烯嵌段共聚物)改性沥青和胶粉改性沥青利用动态剪切流变仪(DSR)进行重复蠕变试验,利用原子力显微镜(AFM)进行微观结构观测,比较分析盐冻循环前后两种沥青的微细观结构以及流变学性能的变化,为寒冷地区道路路面材料的选择和使用提供参考依据。AFM测试发现,SBS改性沥青出现“蜂形”结构,冻融循环后,“蜂形”结构出现不同变化;胶粉改性沥青未出现“蜂形”结构,冻融循环后胶粉改性沥青表面形貌相差不大;重复蠕变试验结果显示:冻融循环前后SBS改性沥青和胶粉改性沥青永久变形与卸载瞬时应变的比值(εP/εL)在加载初期均随着加载次数的增加而增加,一定次数后达到稳定状态;冻融循环后SBS改性沥青的εP/εL降低,胶粉改性沥青的εP/εL基本不变;利用Burgers模型拟合得到蠕变劲度的黏性成分G_v,冻融循环后SBS改性沥青G_v值小于原样SBS改性沥青,胶粉改性沥青G_v值大于原样胶粉改性沥青,且两种沥青水冻循环与盐冻循环G_v值差别不大。胶粉改性沥青具有更好的高温使用性能。
In order to investigate the performance changes of pavement materials in the melting salt environment, dynamic shear flow was used to modify SBS (styrene-butadiene-styrene block copolymer) modified asphalt and rubber powder used in the cold region of Inner Mongolia. (DSR) were used to conduct repeated creep tests. Microstructure observation was carried out by using atomic force microscope (AFM). The microstructure and rheological properties of two kinds of asphalt before and after salt-frost cycle were compared and analyzed. For the road pavement materials in cold area Selection and use of reference. AFM test showed that SBS modified bitumen appeared “bee” structure, and the structure of “bee” changed after freeze-thaw cycle. The “bumble bee” The results of repeated creep test showed that the ratio of permanent strain to unloading instantaneous strain (εP / εL) of SBS modified asphalt and rubber modified asphalt before and after the freeze-thaw cycles The initial stage of the modified asphalt increased with the increase of the loading times and reached a steady state after a certain number of cycles. The εP / εL of the SBS modified asphalt decreased after the freeze-thaw cycles, while the εP / εL of the rubber modified asphalt remained almost unchanged. Get creep stiffness of the viscous component G_v, freeze-thaw cycle SBS modified asphalt G_v value is less than the original SBS modified asphalt, rubber modified asphalt G_v value is greater than the original rubber modified asphalt, and two asphalt freeze cycle Salt and salt circulation G_v value difference is not big. Powder modified asphalt has better performance at high temperature.