基于MSCR试验的WMF-SBR复合改性沥青高温老化性能研究
Study on High Temperature Aging Performance of WMF-SBR Composite Modified Asphalt Based on MSCR Test

为了全面提高废口罩纤维(Waste Mask Fiber, WMF)改性沥青的高低温性能，将其与SBR改性剂共同制备WMF-SBR复合改性沥青，基于MSCR流变性能试验，对未老化、FTROT短期老化和PAV长期老化三种状态下的复合改性沥青，测试分析其蠕变恢复率R、不可恢复蠕变柔量J_nr、应力敏感性J_nrdiff、R_diff等指标的变化规律。结果表明，其软化点较基质沥青提高了14.6%，较WMF改性沥青降低了5%，延度较WMF改性沥青增加了380%；在0.1 kPa、3.2 kPa应力作用下，WMF-SBR复合改性沥青的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、减小的趋势变化；与基质沥青、SBR改性沥青相比，WMF-SBR复合改性沥青在相同老化阶段和应力水平条件下，R、R_diff指标均最大，J_nr、J_nrdiff指标均最小。WMF-SBR复合改性沥青显著提高了WMF改性沥青的低温塑性；相比SBR改性沥青，其高温抗车辙变形稳定性更好，弹性变形恢复能力更强，应力敏感性更小，老化后性能更稳定、更耐久。
In order to comprehensively improve the high and low temperature performance of waste mask fiber (Waste Mask Fiber, WMF) modified asphalt, the WMF-SBR composite modified asphalt was prepared with SBR modifying agent. Based on the MSCR rheological performance test, the changes in creep recovery rate R, unrecoverable creep compliance J_nr, stress sensitivity J_nrdiff, and R_diff of composite modified asphalt under three states of unaged, FTROT short-term aging, and PAV long-term aging were tested and analyzed. The results show that, its softening point is 14.6% higher than the matrix asphalt, is 5% lower than the WMF modified bitumen. The extension is 380% higher than that of WMF modified asphalt; under the action of the 0.1 kPa, 3.2 kPa stress, the R value, R_diff value, J_nr value and J_nrdiff value of WMF-SBR composite modified asphalt respectively increase, decrease, decrease and decrease with the increase of aging degree; compared with matrix asphalt and SBR modified bitumen, WMF-SBR composite modified bitumen under the same aging stage and stress level conditions, the indicators (R, R_diff) are the largest and the indicators (J_nr, J_nrdiff) are the minimum. WMF-SBR composite modified asphalt significantly improves the low temperature plasticity of WMF modified asphalt; compared with SBR modified asphalt, it has better high temperature rut deformation stability, more resilient elastic deformation recovery, less stress sensitivity, and more stable and durable performance after aging.