材料期刊网

The microstructure and dynamic rheological characteristics of asphalt containing different polymer modifiers (crumb rubber, styrene-butadiene-styrene and crumb rubber mix with styrene-butadiene-styrene) at mid and high service temperature levels were investigated by using scanning electron microscopy(SEM), dynamic shear rheometer(DSR) and repeat creep test. The main objective of the investigation was to rank the modifiers based on their effect on performance characteristics of asphalt under service conditions. To evaluate the effect of different modiifers on the viscoelastic response of asphalt, the temperature and frequency dependences of the dynamic viscoelastic properties were compared. The mid-temperature fatigue resistance and high-temperature rutting resistance of three polymer modiifed asphalts were evaluated to predict their ifeld performance in roads. Based on the current results, an improved rutting factor was proposed to determine the rutting resistance of asphalt pavements. In addition, the viscous stiffness (Gv), deifned as the reciprocal of viscous compliance, was used to evaluate the high-temperature deformation resistance of asphalt mixtures. The experimental results indicate that the asphalt containing crumb rubber only shows superior performance at mid and high service temperatures in all three modiifed asphalt binders due to the action of the crumb rubber.