纳米碳酸钙/苯乙烯-丁二烯-苯乙烯嵌段共聚物复合改性沥青的制备及性能

采用纳米CaCO3和苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）作为外加剂制备纳米CaCO3/SBS复合改性沥青。通过测试基本物理性能确定了外加剂的最佳掺量，通过流变性能测试、离析试验、荧光显微镜观察及热重分析等考察了沥青的性能及微观形貌。结果表明，两种外加剂复配的最佳比例为5%（质量分数，下同）的纳米CaCO3和4%的SBS；在纳米CaCO3改性沥青中掺加SBS后，复合改性沥青在不同温度下的黏度增大，高温抗车辙能力增强，低温性能得到明显改善，储存稳定性良好；纳米CaCO3分子、SBS分子和基质沥青分子三者具有良好的相容性，经复合改性后沥青的热稳定性增强。

Preparation and properties of nano-calcium carbonate/styrene-butadiene-styrene block copolymer composite modified asphalt

Nano-CaCO3 and styrene-butadiene-styrene block copolymer （SBS） were used as additives to prepare nano-CaCO3/SBS composite modified asphalt. The optimum amount of admixture was determined by testing basic physical properties, the performance and micro morphology of asphalt were investigated by rheological property and segregation test, fluorescence microscope observation and thermogravimetric analysis. The results showed that the best proportion of the two admixtures was 5% （mass fraction, the same below） of nano-CaCO3 and 4% of SBS. After adding SBS into nano-CaCO3 modified asphalt, the viscosity of the composite modified asphalt increased at different temperatures, high temperature rutting resistance and low-temperature performance was significantly improved, and storage stability was good. Nano-CaCO3 molecule, SBS molecule and matrix asphalt molecule had good compatibility, and the thermal stability of asphalt was enhanced because of the composite modification.