Abstract: The asphalt binder was prone to ageing under cold and high altitude, which increased the cracking risk of asphalt pavement. In order to study the performance variation rule of asphalt binder under the action of large temperature difference and ultraviolet radiation, the region with large temperature difference and the region with ultraviolet radiation in Tibet were defined by taking the average daily temperature difference and the average daily total solar radiation over the years as indicators, and Tibet area was divided into 6 districts. The performance variation of asphalt binder under the coupling action of different temperature and ultraviolet radiation was studied by simulating the environment with various temperature differences and ultraviolet radiation of Tibet. The research results show that different temperature differences have little effect on the conventional physical properties, high and low temperature performance and composition changes of asphalt binder. The coupling effect of super-large temperature difference and strong ultraviolet radiation has a significant impact on the conventional physical properties of the matrix asphalt. The creep stiffness and creep rate of SBR modified asphalt have the smallest variation range, and the low-temperature crack resistance is better. The rutting factor of SBS modified asphalt has smaller increment and its high-temperature rutting resistance is better. The increment of matrix asphalt carbonyl index IC=O and sulfoxide index IS=O is 1.3 times as much as that of the modified asphalt, the colloid stability index difference was 1.4 times as much as that of the modified asphalt, and the aging degree is severe.

Key words: highway engineering; large temperature difference; ultraviolet radiation; partition; coupling

摘要： 大温差、紫外辐射条件下沥青胶结料容易老化，会增大沥青路面的开裂风险。为研究沥青胶结料在大温差、紫外辐射作用下的性能变化规律，以累年日平均温差、累年日平均太阳辐射总量为指标定义西藏地区大温差区和紫外辐射区，将西藏地区划分为6个区，通过模拟西藏地区不同温差、紫外辐射环境，研究沥青胶结料在不同温差和紫外辐射耦合作用下的性能变化。研究结果表明：不同温差对沥青胶结料的常规物理性能、高低温性能和成分变化影响较小；特大温差、强紫外辐射耦合作用，对基质沥青的常规物理性能影响较大；SBR改性沥青的蠕变劲度和蠕变速率变化幅度最小，低温抗裂性能更优；SBS改性沥青的车辙因子增长幅度较小，高温抗车辙性能更好；基质沥青羰基指数IC=O和亚砜基指数IS=O的增长幅度约为改性沥青的1.3倍，胶体稳定指数差值约为改性沥青的1.4倍，老化程度严重。

关键词: 道路工程；大温差；紫外辐射；分区；耦合