Abstract: Recycled asphalt technology is a crucial means to enhance the utilization rate of waste asphalt mixture and achieve sustainable development in asphalt road construction. However, due to the high degree of aging of old asphalt, its performance after regeneration with ordinary rejuvenator often fails to meet the demands of long-term use. To address this issue, taking recycled asphalt as the research object, the physical indicators, rheological properties, component content, molecular weight distribution and absorbance of asphalt before and after recycling were comparatively analyzed, through conventional tests, dynamic shear rheological (DSR) test, bending beam rheological (BBR) test, SARA test, gel permeation chromatography (GPC) test and ultraviolet-visible absorption spectrum (UV-Vis) test. The results show that: after short-term and long-term aging of asphalt, the rheological properties and microscopic indicators of the recycled asphalt are closest to those of matrix asphalt when the amount of rejuvenator is 4%~6% and 12%~14%, respectively. The aging process will lead to an increase in the proportion of components with larger molecular weights in the asphalt, and the regenerant will restore the performance by increasing the proportion of components with smaller molecular weights in the recycled asphalt. Compared to the aged asphalt, the residual penetration and residual ductility ratio of recycled asphalt increase, the increment of softening point decreases, and the absorbance index is greater than that of aged asphalt and original asphalt. The anti-aging performance of recycled asphalt is close to that of original asphalt. The residual penetration, residual ductility ratio, softening point increment and absorbance can be used as indicators to evaluate the anti-aging performance of recycled asphalt.

Key words: highway engineering; recycled asphalt; anti-aging; rheological property; ultraviolet spectrum

摘要： 再生沥青技术是提升废旧沥青混合料利用率、实现沥青道路建设可持续发展的重要手段。然而，老旧沥青因老化程度较高，普通再生剂再生后其性能难以满足长期使用需求。针对这一问题，以再生沥青为研究对象，通过常规试验及动态剪切流变、弯曲梁流变、四组分、凝胶渗透色谱、 紫外-可见吸收光谱试验对比分析了沥青再生前后的物理指标、流变特性、组分含量、分子量分布及吸光度。结果表明：沥青短期、长期老化后，再生剂掺量分别为4%~6%、12%~14%时的再生沥青流变性能与微观指标最接近基质沥青；老化过程会导致沥青中分子量较大的成分比例增加，再生剂通过增大再生沥青中分子量较小的成分比例恢复性能；再生沥青相较于老化沥青的残留针入度、残留延度比增大，软化点增量减小，且吸光度指标大于老化沥青与原样沥青。再生沥青的抗老化性能接近于原样沥青，残留针入度、残留延度比、软化点增量与吸光度可以作为评价再生沥青抗老化性能的指标。

关键词: 道路工程；再生沥青；抗老化；流变性能；紫外光谱