利用动态剪切流变仪、荧光显微镜等手段研究不同结构PE改性沥青的黏弹性能、微观结构、黏温特性等,从聚合物分子结构的角度阐述改性沥青性能的差别及原因。结果表明：改性沥青在相同温度下的储存模量G＇和损失模量G〞由大到小顺序为HDPE、LDPE、VPE,储存模量G＇随温度降低幅度大小顺序为VPE、LDPE、HDPE；相同温度下沥青质含量较低的ZH沥青的储存模量G＇小于QHD沥青的；PE以不规则颗粒分散在沥青相中,LDPE分散最均匀,粒子为球状且直径约为20μm；HDPE的粒子形状不规则且粒径多数大于100μm；PE改性沥青微观结构及黏弹力学性能的差别是由于PE分子间距、分子柔顺性及结晶度的差异造成的；HDPE对沥青的黏弹力学性能和高温性能的提高效果最明显,HDPE合适的掺加量为4%~5%。%Effects of polyethylene molecular structure on the viscoelastic properties, microstructure, and viscosity-tempera-ture properties of PE modified asphalt were studied by means of dynamic shear rheometer and fluorescence microscopy, etc. The discrepancy of various polyethylene modified asphalt on performance was illustrated from the perspective of the polymer molecular structure. The results indicate that storage modulus G'and loss modulus G〞of various binders decrease by the or-der of HDPE, LDPE and VPE, while the descending degree of storage modulus G' with temperature diminished by VPE, LDPE and HDPE. The storage modulus of ZH asphalt is less than that of QHD asphalt because the asphaltene content in ZH asphalt is smaller. The particles of PE dispersed in asphalt are irregular and the particles of LDPE are the most uniform with diameters of 20 μm. Dispersed particles of HDPE are irregular and most of them are greater than 100 μm. The difference of the viscoelastic properties and microscopy among various polyethylene modified asphalts are caused by intermolecular dis-tance, molecular flexibility and crystallinity. Meanwhile, HDPE is the most effective additive for asphalt modification, which enhances the mechanics and high-temperature performance. And the appropriate adding percentage of HDPE to asphalt is from 4% to 5%.
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