盐冻融循环条件下沥青高温流变性能及微观结构

发布时间：2018-08-04 16:15

【摘要】：利用动态剪切流变仪(DSR)和原子力显微镜(AFM)对冻融循环前后的基质沥青和胶粉改性沥青进行测试,比较分析了不同盐浓度和冻融循环次数下两种沥青的动态黏弹参数及微观结构,并测试了冻融前后两种沥青的基本指标。结果表明:经历冻融循环后,基质沥青储存模量和车辙因子均增加,疲劳因子减小,而胶粉改性沥青没有明显变化,冻融循环增加了基质沥青的高温弹性性能,但显著降低了抗疲劳性能,而冻融循环对胶粉改性沥青的高温性能影响不大;AFM观测表明基质沥青出现"蜂形"结构,冻融循环后"蜂形"变大、变长,而胶粉改性沥青的结构几乎没有变化,因此北方寒冷地区使用胶粉改性沥青作为路面材料更具优势。
[Abstract]:Dynamic shear rheometer (DSR) and atomic force microscope (AFM) were used to test the asphalt matrix and rubber powder modified asphalt before and after freeze-thaw cycle. The dynamic viscoelastic parameters and microstructure of the two kinds of asphalt under different salt concentration and freeze-thaw cycle times were compared and analyzed. The basic indexes of two kinds of asphalt before and after freezing and thawing were tested. The results showed that the storage modulus and rutting factor of matrix asphalt increased and the fatigue factor decreased after freeze-thaw cycle, while the asphalt modified by rubber powder did not change obviously. Freeze-thaw cycle increased the high temperature elasticity of matrix asphalt. However, the fatigue resistance of asphalt modified by freezing and thawing was significantly reduced, but the effect of freeze-thaw cycle on the high temperature performance of modified asphalt was not significant. AFM observation showed that the "bee" structure appeared in the matrix asphalt, and the "bee shape" became larger and longer after freeze-thaw cycle. However, the structure of rubber powder modified asphalt has almost no change, so it is more advantageous to use rubber powder modified asphalt as pavement material in cold area of northern China.
【作者单位】：内蒙古工业大学土木工程学院;内蒙古电力科学研究院;
【基金】：国家自然科学基金(11162010)
【分类号】：U414

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