光稳定改性沥青材料热老化行为特征研究

为了明确高温老化对光稳定改性沥青材料的作用效应, 优选受阻胺光稳定剂制备改性沥青, 设置热老化温度及时间对光稳定改性沥青进行热老化处置, 借助三大指标试验及布氏黏度试验系统研究热老化作用对光稳定改性沥青胶结料路用性能的影响规律, 采用原子力显微镜(Atomic Force Microscope, AFM)表征不同热老化条件下光稳定改性沥青表面粗糙度变化, 通过3D形貌重建深入分析热老化作用对于沥青微观形貌的影响, 明确热老化作用对于光稳定改性沥青的影响。结果表明: T770改性剂能够缓解热老化作用对于沥青胶结料的影响; 在热老化时间大于6 h后, 基质沥青中均有蜂状结构出现, 随着老化时间的增加, 基质沥青表面形成的特殊结构逐渐变小; T770改性沥青在老化时间6 h和9 h时均出现了蜂状结构; 根据粗糙度的数据对比, 改性沥青的表面起伏程度要比基质沥青更大。这表明在热老化作用下T770改性沥青的表面粗糙度变化程度要略高于基质沥青胶结料, 即光稳定改性沥青材料对于热老化具有更高的敏感性。

Thermal Aging Behavior Characteristics of Light Stabilized Modified Asphalt Materials

In order to clarify the effect of high temperature aging on light-stable modified asphalt materials, hindered amine light stabilizer was selected to prepare modified asphalt. The light-stablized modified asphalt is subjected to thermal aging treatment under different temperature and time conditions. The influence of thermal aging on the road performance of light-stabilized modified asphalt binder was studied by means of three index tests and Brookfield viscosity test. Atomic Force Microscope (Atomic Force Microscope, AFM) was used to characterize the surface roughness changes of light-stablized modified asphalt under different thermal aging conditions. The influence of thermal aging on the microscopic morphology of asphalt was analyzed by 3D morphology reconstruction and the influence of thermal aging on light-stable modified asphalt was clarified. The results showed that T770 modifier can alleviate the effect of thermal aging on asphalt binder. When the heat aging time exceeded 6 hours, honeycomb structures appeared in the base asphalt. As the aging time increased, the special structure formed on the surface of the base asphalt became smaller gradually. At 6h and 9h, honeycomb structure appeared in the T770 modified asphalt. According to the comparison of roughness data, the surface undulation of modified asphalt was greater than that of base asphalt, which indicated that under the action of heat aging the surface roughness of T770 modified asphalt was slightly higher than that of the base asphalt binder, demonstrating that the light-stable modified asphalt material had the higher sensitivity to heat aging.