基于流变性能的再生剂用量确定方法

丁彬^1，2，徐金玉^1，2，袁梦^1，2，韩超^1，2，岳学军^1，2

1.苏交科集团股份有限公司，江苏 南京  211112；2.新型道路材料国家工程研究中心，江苏 南京  211112

摘要：为提高就地热再生沥青混合料的综合路用性能，基于车辙因子、蠕变劲度、蠕变速率和临界温差等流变性能参数，研究再生剂用量对再生沥青性能的影响，提出根据不同再生剂与回收沥青的质量比下再生沥青连续高温等级和连续低温等级的关系，综合平衡再生沥青高温、低温性能确定再生剂与回收沥青的质量比；根据确定的再生剂与回收沥青的质量比制备沥青混合料，与基于针入度方法确定的再生剂与回收沥青的质量比下沥青混合料的高温、低温性能对比。结果表明：随再生剂与回收沥青的质量比增大，动态剪切流变试验测得的再生沥青车辙因子逐渐减小，弯曲梁流变试验测得的蠕变劲度减小，蠕变速率增大，柔韧性增强。基于连续高温等级和连续低温等级确定再生剂与回收沥青的质量比，以此得到的再生沥青混合料高温性能略降，但浸水马歇尔残留稳定度增大9.4%，冻融劈裂强度比增大7.9%，小梁弯曲破坏应变增大5.5%，能更有效地平衡再生沥青混合料高温和低温性能。

关键词：就地热再生；再生剂；流变性能；沥青性能等级；高低温性能平衡

The determination method of the rejuvenator dosage based on rheological property

DING Bin^1,2, XU Jinyu^1,2, YUAN Meng^1,2, HAN Chao^1,2, YUE Xuejun^1,2

1. JSTI GROUP, Nanjing 211112, China; 2. National Engineering Research Center of Advanced Road Materials, Nanjing 211112, China

Abstract: To improve the comprehensive road performance of in-situ recycled asphalt mixtures, this study investigates the impact of the amount of rejuvenator on the performance of recycled asphalt based on rheological performance parameters such as rutting factor, creep stiffness, creep rate, and critical temperature difference. It proposes a method for determining the quality ratio of rejuvenator to reclaimed asphalt based on the relationship between continuous high-temperature grades and continuous low-temperature grades. This method balances the high-temperature and low-temperature performance of asphalt to define the quality ratio of rejuvenator to reclaimed asphalt. Based on the determined quality ratio, asphalt mixtures are prepared, and the high-temperature and low-temperature performance of these mixtures is compared with those determined by the penetration method for the same quality ratio of rejuvenator to reclaimed asphalt. The results indicate that as the quality ratio of rejuvenator to reclaimed asphalt increases, the rutting factor of recycled asphalt measured by dynamic shear rheology gradually decreases, the creep stiffness measured by bending beam rheology decreases, the creep rate increases, and flexibility improves. The quality ratio of rejuvenator to reclaimed asphalt determined based on continuous high-temperature and low-temperature grades results in a slight decrease in the high-temperature performance of the recycled asphalt mixture, but the water-saturated Marshall residual stability increases by 9.4%, the freeze-thaw splitting tensile strength ratio increases by 7.9%, and the bending failure strain of the small beam increases by 5.5%, effectively balancing the high-temperature and low-temperature performance of the recycled asphalt mixture.

Keywords: geothermal regeneration; rejuvenator; rheological property; PG; balance of high and low temperature performance