高温剪切时间对废橡胶-沥青相容性的影响

Influence of High-Temperature Shearing Time on Compatibility Between Waste Rubber and Bitumen

废弃橡胶与沥青之间的相容性决定了橡胶沥青的工程性能。在180℃和1 h、5 h条件下采用废弃轮胎橡胶粉分别对沥青进行短期和长期剪切改性,通过胶粉残余量、动态剪切流变和多重应力蠕变恢复等试验及傅里叶变换光谱表征,研究高温剪切时间对橡胶-沥青相容性的影响。结果表明:在180℃高温条件下,剪切时间从1 h延长至5 h,橡胶沥青的胶粉残余量和特征官能团无明显变化,且改性沥青的高温性能和黏弹性能也无明显改善。高温剪切时间的延长不能促使橡胶发生明显降解而改善橡胶与沥青之间的相容性。

The compatibility between waste rubber and bitumen determines the engineering performances of rubberized bitumen.This study adopts the crumb rubber derived from waste tires to modify bitumen at 180℃for 1 h and 5 h,respectively.Through the experimental tests of residual crumb rubber mass ratio,dynamic shear rheology,and multiple stress creep recovery,and characterization of Fourier transform infrared spectroscopy,the influence of shearing time on the compatibility between rubber and bitumen was investigated.The results indicat that when the shearing time increases from 1 h to 5 h at 180℃,there are no remarkable changes in the residual crumb rubber mass ratio and characteristic functional groups of the rubberized bitumen.Meanwhile,the high temperature performance and viscoelasticity of the rubberized bitumen are not significantly improved,which demonstrates that the increase of high-temperature shearing time can not promote the degradation of rubber,and has little effect on the compatibility between rubber and bitumen.