石墨烯/SBS复合改性沥青混合料性能研究

Study on properties of asphalt modified with SBS/graphene composite

为研究石墨烯含量对苯乙烯⁃丁二烯⁃苯乙烯嵌段共聚物(SBS)改性沥青混合料性能的影响,以SBS改性沥青为原材料,分别将质量为沥青质量0.1%、0.2%、0.3%的石墨烯加入其中以制备复合改性沥青,并对其性能进行评价。而后对不同石墨烯含量的复合改性沥青混合料的高温稳定性、低温抗裂性、水稳定性能进行评价。并根据雷达图来确定石墨烯的最佳含量。最后,采荧光显微镜及扫描电子显微镜分析石墨烯对SBS改性沥青的作用机理。结果表明,由于石墨烯的引入,沥青结合料的针入度明显下降、软化点显著提升,延度明显下降。就路用性能而言,石墨烯的加入显著提升了SBS改性沥青混合料的抗车辙能力,低温抗裂性及水稳定性则略有降低。雷达图表明0.2%含量的石墨烯的综合性能最好,即石墨烯的最佳含量为0.2%。在石墨烯与SBS改性沥青混合过程中,石墨烯的层状结构和较大的比表面积使其易于与沥青分子混合;同时,石墨烯在与SBS改性沥青混合的过程中可以被苯乙烯⁃丁二烯⁃苯乙烯插入,从而产生稳定的物理交联,提升SBS改性沥青混合料的性能。

To evaluate the effect of graphene content on the properties of SBS⁃modified asphalt mixture,SBS⁃modified as⁃phalt was used as a raw material and graphene as a modifier to prepare asphalt composites with graphene contents of 0.1,0.2,and 0.3 wt%.The properties of the resultant modified asphalt mixture were evaluated,and their high temperature stability,low temperature crack resistance,and water were investigated.The optimal addition amount of graphene was determined according to the radar map.The modification mechanism of graphene for the SBS⁃modified asphalt was ana⁃lyzed through fluorescence sampling microscope and SEM.The results indicated that the penetration of the modified as⁃phalt mixtures decreased significantly but their softening point increased significantly due to the presence of graphene.Moreover,their ductility also decreased remarkably.In terms of road performance,the addition of graphene significantly improved the rutting resistance of the SBS⁃modified asphalt mixtures,whereas their low temperature crack resistance and water stability were slightly reduced.The radar map test results indicated that the modified asphalt mixtures obtained the best comprehensive performance at a graphene content of 0.2 wt%.In the mixing process of the SBS⁃modified asphalt with graphene,a lamellar structure and a large specific surface area of graphene make it easy to mix with asphalt mole⁃cules.Meanwhile,SBS can insert into graphene during the mixing process,resulting in stable physical crosslinking and improving the performance of the SBS⁃modified asphalt mixtures accordingly.