基于纳米尺度参数的沥青抗紫外线老化性能评价

Evaluation of asphalt anti-ultraviolet aging performance based on nanoscale parameters

为了探索沥青紫外线老化过程中纳米形态的变化规律,选取90#沥青和苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS I-C)改性沥青为原材料,利用紫外线老化箱进行紫外线老化试验,测取不同紫外线老化时间的残留针入度、残留延度及原子力显微扫描图片,分析紫外线老化过程中沥青的纳观形貌变化规律及其与沥青相关技术指标间的关系。结果表明:90#沥青的间隙结构连续且覆盖范围大,SBS I-C改性沥青的蜂状结构体积相对较小且密集;两种沥青的纳米尺度参数(粗糙度及最大起伏高差)在紫外线老化过程中均迅速增大,90#沥青增速更大,纳米尺度参数最终增加幅度也较大;纳米尺度参数与残留针入度及残留延度呈负相关关系,其变化量与沥青性能的损失量成正相关关系;纳米尺度参数变化幅度越小,其抗紫外线老化性能则越强。

In order to explore the changes of nanoscale parameters of asphalt in the process of ultraviolet aging,90#asphalt and styrene-butadiene-styrene block copolymer(SBS I-C)modified asphalt was selected as raw materials,and ultraviolet(UV)aging tests were carried out with the help of the ultraviolet aging chamber.The residual penetration,residual ductility and atomic force microscope scanning images of asphalt at the different aging time were measured.The nano morphology changes of asphalt during ultraviolet aging and the relationship with asphalt related technical indexes were also analyzed.The results show that the gap structure of 90#asphalt is continuous and covers a large area,while the honeycomb structure of SBSΙ-C modified asphalt is relatively small and dense;the nanoscale parameters(roughness and maximum fluctuation height difference)of the two kinds of asphalt both increase rapidly during the aging process,but the growth rate and the final increase magnitude of 90#asphalt are larger;nanoscale parameters have a negative correlation with residual penetration and residual ductility,and the amount of change is positively related to the loss of asphalt performance.The smaller the change of nanoscale parameters,the stronger the anti-aging performance.