基于MSCR试验的废口罩纤维改性沥青高温老化性能研究

Study on the High-Temperature Aging Performance of Waste Mask Fiber-Modified Asphalt Based on MSCR Test

摘要: 为了有效高值再利用废弃口罩以减少资源浪费，本研究将废弃口罩作为道路沥青的改性剂。通过MSCR试验，采用不可恢复的蠕变柔度J_nr、蠕变恢复率R以及应力敏感性指标J_nrdiff、R_diff等作为评价指标，分析了废口罩纤维改性沥青在未老化、短期老化和长期老化三种状态下的高温性能变化规律。结果表明：废口罩纤维改性沥青较基质沥青的软化点明显升高，延度、针入度下降；废口罩纤维改性沥青的R值、R_diff值、J_nr值、J_nrdiff值随老化程度的增加分别呈增大、减小、减小、先增后减的趋势变化；在相同老化阶段和应力水平条件下，废口罩纤维改性沥青较基质沥青的蠕变恢复率R值大、不可恢复蠕变柔量J_nr小；在相同应力水平条件下，废口罩纤维改性沥青较基质沥青老化前后的蠕变恢复率R值的增幅大、不可恢复蠕变柔量J_nr和应力敏感性指标Rdiff的减幅小。废口罩纤维的加入可以提高沥青的高温或重载抗变形能力和弹性变形恢复能力，抗老化性能更好，疲劳寿命更长。

Abstract: In order to effectively reuse waste masks at high value to reduce the waste of resources, waste masks were used as modifiers of road asphalt in this study. Through the MSCR test, the unrecoverable creep flexibility J_nr, creep recovery rate R and stress sensitivity index J_nrdiff, R_diff, etc. were used as evaluation indexes to analyze the change rule of high-temperature performance of waste mask fiber-modified asphalt in the three states of unaged, short-term aging and long-term aging. The results show that the softening point of waste mask fiber-modified asphalt is significantly higher than that of matrix asphalt, and the ductility and needle penetration decrease; the R value, R_diff value, J_nr value, and J_nrdiff value of waste mask fiber-modified asphalt with the increase in the degree of aging were increasing, decreasing, decreasing, and first increasing and then decreasing trend; in the same aging stage and stress level conditions, the waste mask fiber-modified asphalt compared with the matrix asphalt creep recovery rate R value is large, unrecoverable creep flexibility J_nr is small; in the same stress level conditions, waste mask fiber-modified asphalt than matrix asphalt before and after the aging of the creep recovery rate of R value increase is large, unrecoverable creep flexibility J_nr and stress sensitivity index R_diff decrease is small. The addition of waste mask fiber can improve the asphalt’s high-temperature or heavy-load deformation resistance and elastic deformation recovery ability, better aging resistance and longer fatigue life.