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Jnr、应力敏感性Jnrdiff、Rdiff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、Rdiff值、Jnr值、Jnrdiff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、Rdiff指标均最大,Jnr、Jnrdiff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 Jnr, stress sensitivity Jnrdiff, and Rdiff 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, Rdiff value, Jnr value and Jnrdiff 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, Rdiff) are the largest and the indicators (Jnr, Jnrdiff) 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.