硅粉/SBS复合改性沥青改性机理

Modified mechanism of silica fume/SBS composite modified asphalt

采用高速剪切工艺确定了硅粉/SBS(苯乙烯-丁二烯-苯乙烯嵌段共聚物)复合改性沥青的制备方案,通过扫描电镜试验(SEM)分析了硅粉、SBS微粒在沥青基体中的溶胀情况及改性沥青的微观形貌,并利用红外光谱试验(FTIR)对比分析了加入硅粉和SBS进行复合改性作用前、后沥青的光谱图,揭示了硅粉/SBS复合改性沥青的改性机理.研究结果表明:改性剂在沥青中分散均匀,混溶极好,硅粉的掺入促进了SBS微粒与沥青间的吸附及溶胀反应,提高了混合体系的整体稳定性及力学性能;复合改性后的沥青中检测到了SBS和硅粉的存在,并且在该FTIR图谱中并未发现不同于沥青、硅粉和SBS三者的新红外吸收峰出现,说明复合改性过程中并未出现新的官能团,复合改性过程是一个物理混溶的过程.

High speed shearing technique was used to determine the preparation scheme of silica fume/SBS composite modified asphalt.Based on scanning electron microscope(SEM),the swelling condition of silica fume and SBS in the asphalt matrix and microstructure of the composite modified asphalt are analyzed.Based on the infrared spectra(FTIR),the mechanism of silica fume/SBS composite modified asphalt is revealed by comparing the spectrogram of asphalt matrix with adding silica fume and SBS.The results show that the modified agent is uniformly dispersed in asphalt,and the miscibility is excellent.The incorporation of silica fume enhanced adsorption and swelling reaction between SBS particles and asphalt,and improved the overall stability and mechanical properties of the mixed system.Silica and SBS was detected in the composite modified asphalt and there was no new infrared absorption peak,indicating that the composite modified process did no create new functional groups,and the compound modification process is a physical miscible process.