【摘要】 传统的聚合物改性沥青在某些性能上仍不尽人意，而聚氨酯自身结构优势突出，能用来弥补常见改性剂的缺陷。为此，制备PU改性沥青，通过旋转薄膜烘箱加热实验评价PU改性沥青的抗老化性；利用动态剪切流变实验、弯曲梁流变实验对比分析PU改性沥青与90#基质沥青、SBS改性沥青的流变行为；采用傅里叶变换红外光谱研究PU改性沥青的改性机理。研究结果表明：PU改性沥青老化前后针入度、软化点、延度的比率分别为91%、97%、85%,PU改性沥青抗热氧老化性能优异；PU改性沥青在52～82℃时具有最优的高温性能；PU改性剂的加入改善了沥青的低温流变性能。更多还原

【Abstract】 Traditional polymer modified asphalt is still unsatisfactory in some properties, but polyurethane(PU) has outstanding structural advantages and can be used to make up for the defects of common modifiers. The preparation process parameters of PU modified asphalt prepared in this study are as follows. The aging resistance of PU modified asphalt is evaluated by rotating film oven heating experiment(RTFOT). Dynamic shear rheological test(DSR) and bent beam rheological test(BBR) are used to compare the rheological behavior of PU prepolymer modified asphalt with 90# base asphalt and SBS modified asphalt. Fourier transform infrared spectroscopy(FTIR) is used to study the modification mechanism of PU modified asphalt. The results show that the penetration, softening point and elongation ratios of PU modified asphalt before and after aging are 91%, 97% and 85%, respectively, which indicates that PU modified asphalt has excellent thermal and oxygen aging resistance. DSR test shows that PU modified asphalt has the best high temperature performance between 52 ℃ and 82 ℃. BBR test shows that the addition of PU modifier improves the low temperature rheological property of asphalt.更多还原