盐冻循环对沥青性能及其微观结构的影响

Research on the performance and microstructure of asphalt under salt freezing cycle

对基质沥青、SBS改性沥青和胶粉改性沥青在盐冻循环前后的3个基本指标进行了测试,采用极差分析法和灰色关联熵分析法对盐冻融循环前后影响沥青高低温性能的各因素进行了对比分析,并通过扫描电子显微镜对冻融循环前后的3种沥青试样的微观结构进行观测。结果表明,冰冻温度、盐溶液浓度和冻融循环次数都会影响沥青的温度敏感性,使沥青的高低温性能降低,并对沥青微观结构产生巨大影响,但是研究也发现沥青自身性能指标的影响更为显著,特别是沥青自身的针入度值。因此在寒冷地区修建道路时,沥青材料的选用要严格控制其基本指标。

The three routine indicators for the matrix asphalt,SBS modified asphalt and rubber powder modified asphalt were tested before and after the salt freezing. The influence factors that would change the high and low temperature performance of the asphalt were analyzed through range analysis method and grey relation entropy method,and the scanning electron microscope( SEM) was used to observe the microstructure of the three kinds of asphalt before and after the salt freezing. The analysis results showed that freezing temperature,concentration of salt solution,freezing and thawing cycles would affect the temperature sensitivity,reduce the high and low temperature performance and change the microstructure of the asphalt greatly. But the study also indicated that the performance of the asphalt itself was more important than others especially for penetration value of asphalt. So how to select suitable asphalt for road in the cold region should be strictly controlled.