紫外光吸收剂对不同嵌段比SBS改性沥青性能的影响

Effect of Ultraviolet Absorber on Properties of SBS Modified Bitumen with Different Block Ratios

为了研究紫外光吸收剂(UV-531)对不同嵌段比SBS改性沥青性能的影响,采用高速剪切仪制备不同嵌段比(分别为40/60、30/70、20/80)SBS改性沥青,通过熔融共混的方法分别掺加3种剂量UV-531制成UV-SBS改性沥青。利用动态剪切流变试验、弯曲梁流变试验和测力延度试验探究了不同掺量UV-531和不同嵌段比对沥青高、低温性能的影响规律。结果表明:UV-531的加入对嵌段比为20/80的SBS改性沥青高低温性能改善效果不明显,对其他两种嵌段比SBS改性沥青的改善效果显著。使用室内紫外光老化环境箱模拟了沥青的紫外老化,借助软化点增量、G*AI和红外光谱分别研究了UV-SBS改性沥青的老化程度和化学机理。从沥青抗紫外老化程度来看,选择最佳掺量UV-531的嵌段比为40/60和20/80的SBS改性沥青的抗紫外老化效果相当,均远远优于嵌段比为30/70的SBS改性沥青。

To study the effect of ultraviolet absorber （UV-531） on peoperties of SBS modified bitumen with different block ratios, the SBS modified asphalt with different block ratios（40/60,30/70,20/80） were prepared with the high speed shearing apparatus,and the UV-SBS modified asphalt was prepared with three doses of UV-531 by the melt blending method. The effects of different dosages of UV-531 and different block ratios on the high and low temperature perform- ance of asphalt were studied by the dynamic shear rheological test,the bending beam rheological test and the force ductili- ty test. The experimental results show that the effect of UV-531 addition on the improvement of high and low temperature performance of SBS modified asphalt with the block ratio of 20/80 is not obvious, while the improvement effects of the other two block ratios SBS modified asphalt are obvious. In this paper,the aging of asphalt was simulated by using indoor ultraviolet aging environment chamber,and the aging degree and chemical mechanism of UVSBS modified asphalt were studied by using softening point increment,G＊ AI and IR spectra. According to the degree of anti ultraviolet aging of as- phalt,the effect of anti ultraviolet aging of SBS modified asphalt with the optimum content of UV-531 was 40/60 and 20/ 80, which was much better than that of SBS modified asphalt with block ratio of 30/70.