表面有机化硅藻土-胶粉复合改性沥青性能研究

Study on the performance of surface organic diatomite-crumb rubber composite modified asphalt

制备了硅烷偶联剂KH550表面改性硅藻土-胶粉复合改性沥青,通过针入度、软化点及延度测试,离析实验和动态剪切流变分析研究了KH550用量对复合改性沥青的路用性能和贮存稳定性的影响,并以红外光谱和电子显微镜对改性沥青的结构和形貌进行了分析。结果表明:表面有机化硅藻土提升了胶粉改性沥青的路用性能和贮存稳定性。KH550的最佳添加质量分数为5%,改性后的沥青针入度降低13.2%,软化点和延度分别提高14.7%,20.3%,离析软化点差降至2.1℃,高温抗车辙性能有所提升。硅藻土表面亲水基团被取代并生成有机裹覆膜,胶粉颗粒分散均匀。

The silane coupling agent KH550 surface modified diatomite-crumb rubber composite modified asphalt was prepared.The effect of KH550 content on the road performance and storage stability of composite modified asphalt were investigated by testings of penetration, softening point and ductility, segregation experiment and dynamic shear rheological analysis. The structure and morphology of modified asphalt were analyzed by infrared spectroscopy and electron microscope. The results showed that the road performance and storage stability of the crumb rubber modified asphalt were improved by the surface organic diatomite. The best added mass fraction of KH550 was 5% and the penetration of modified asphalt was reduced by 13.2%,the softening point and ductility were increased by 14.7% and 20.3%, respectively. The segregation softening point difference was reduced to 2.1 ℃,and the high-temperature rutting resistance performance was somewhat promoted. The hydrophilic groups on the surface of diatomaceous earth were replaced to form an organic coating film,and the rubber powder particles were evenly dispersed.