复合胶粉改性沥青的微观结构与流变特性

Micro-Structure and Rheological Behavior of Composite Crumb Rubber Modified Asphalt

在基质沥青中加入18%的废胎橡胶粉和2%的SBS,通过湿法得到复合胶粉改性沥青(CCRMA)。采用扫描电镜(SEM)和动态力学的方法(DSR)研究了改性沥青的微观结构和较宽温度范围的流变性能;通过对复数模量主曲线的拟合,在更宽频率范围内研究该沥青的流变特性。结果表明,胶粉颗粒的表面网状结构可很好地吸附沥青,改性后的沥青中形成了一种非均相的稳定结构;在较高的温度下仍保持一定的弹性,感温性能较普通沥青好;随温度的降低,模量的变化及相位角变化趋于缓和,始终保持一定的流动性,从而改善了其柔韧性,提高了抗低温开裂性,该沥青具有较好的工程力学性能。

Composite crumb rubber modified asphalt（CCRMA） was obtained by adding 18 percent waste tire rubber powders and 2 percent styrene-butadiene-styrene copolymer（SBS） into base asphalt by means of wet process.The rheological characterization and micro-structure of the rubber powder modified asphalt were studied by using dynamic shear rheometer（DSR） over wide range of temperatures and scanning electron microscope（SEM）;the complex module master curve was fitting,therefore the rheological behavior of the asphalt can be studied in a wider frequency range. The results indicate that the network structure of rubber powers can adsorb asphalt commendably,so that the heteropolymer structure is formed in the modified asphalt,which makes the binder elasticity increase at high temperature,the temperature sensitivity is improved.The phase angle and module change a little with the temperature reducing,showing that there exists the trend to maintain certain fluidity,resulting in its flexibility improved and anti-breakage at low temperature enhanced;so CCRMA has good engineering mechanical properties.