有砟轨道沥青级配碎石基床复合改性沥青性能研究

沥青级配碎石基床可作为防水层和结构强化层应用于高速铁路有砟轨道中,但常用的SBS改性沥青无法满足其使用要求。本文通过室内老化试验、动态剪切流变(DSR)试验、多重应力蠕变恢复(MSCR)试验、弯曲梁流变(BBR)试验、线性振幅扫描(LAS)试验、傅里叶变换红外光谱(FTIR)分析等试验与分析手段,对不同增强剂掺量的复合改性沥青性能进行研究。结果表明:添加增强剂后复合改性沥青的高温抗变形、中温抗开裂以及抗老化性能均有明显改善,且随增强剂掺量的增加改善效果越来越好,但低温抗开裂性能基本没有受影响。根据沥青级配碎石基床的使用要求,推荐采用SBS+8%增强剂的复合改性沥青方案。

Study on Performance of Composite Modified Asphalt in Ballast Track Subgrade Bed Consisted of Asphalt Graded Crushed Stone

Asphalt graded crushed stone subgrade bed can be used as waterproof layer and structural reinforcement layer in high speed railway ballastless track,but the commonly used SBS modified asphalt can not meet its use requirements.The properties of composite modified asphalt with different reinforcing agent content were tested by indoor aging,dynamic shear rheometer(DSR),multiple stress creep and recovery(MSCR),bending beam rheometer(BBR),linear amplitude sweep(LAS) and Fourier transform infrared spectroscopy(FTIR).The results show that the high temperature deformation resistance,medium temperature cracking resistance and aging resistance of the composite modified asphalt are improved obviously after adding the reinforcing agent,but the low temperature cracking resistance is basically not affected.According to the requirements of asphalt graded crushed stone subgrade bed,it is recommended to adopt SBS+8% reinforcing agent composite modified asphalt scheme.