高黏高弹改性沥青改性机理及性能研究

Research on Modification Mechanism and Performance of HVE-MB

采用SBS、增黏剂、橡胶粉、增塑剂和稳定剂对原样沥青进行复合改性,制备高黏高弹改性沥青(HVE-MB),具有技术和经济优势。通过相容性、改性前后化学结构变化和微观分布状态,揭示了HVE-MB的改性机理。通过60℃动力黏度、布氏旋转黏度、弹性恢复、针入度、软化点、延度和DSR等试验对沥青胶结料的黏弹性能、物理性能、流变性能和温度敏感性能进行评价,对HVE-MB技术性能进行了研究。结果表明,改性沥青荧光分布较均匀,可达到较理想的分散效果,高黏高弹改性剂与沥青主要为物理共混,未发生化学变化。改性剂使原样沥青的黏弹性能显著提升,相对于原样沥青,HVE-MB的动力黏度增大250倍以上,弹性恢复率增大2倍以上,软化点和延度均增大,针入度降低。HVE-MB的各项技术指标均满足高黏高弹改性沥青技术要求,可根据使用工况要求合理设计不同黏度量级的HVE-MB。

SBS,tackifier,rubber powder,plasticizer and oil stabilizer are compounded to modify original bitumen.The preparation of High-viscosity and high-elasticity modified bitumen(HVE-MB)has technical and economic advantages.The modification mechanism of HVE-MB was revealed by compatibility,chemical structure changes before and after modification and microscopic distribution.Through 60℃dynamic viscosity,Brookfield viscosity,elastic recovery,penetration,softening point,ductility,DSR and other experiments,the viscoelasticity,physical properties,rheological properties and temperature sensitivity of bitumen binders were evaluated,and the technical performance of HVE-MB was studied.The results show that the fluorescence distribution of modified bitumen is relatively uniform which can achieve an ideal dispersion effect.The high-viscosity and high-elasticity modifier was mainly physically blended with bitumen without chemical change.The modifier increased significantly the viscosity and elasticity of the original bitumen.The dynamic viscosity of HVE-MB increased by more than 250 times,the elastic recovery rate increased by more than 2 times.Both the softening point and ductility are increased.The penetration decreased.All technical indexes of HVE-MB can meet the technical requirements.HVE-MB with different viscosity levels can be reasonably designed according to the requirements of service conditions.