Effects of Microstructures on the Deformation Characteristics of Modified Asphalt Mixtures at High Temperature

Experimental investigations were carried out for polymer modified binder (PMB) thin film and microtexture of the coarse aggregate's surface, which are microstructure at an intermediate level considered to connect chemical phenomena and physical phenomena in modified asphalt mixtures. It was shown that measuring the viscoelasticity with the thick film is not appropriate and that The G*/sind measurement result of film thickness of 20mm has a high correlation with the flow deformation resistance of the porous asphalt mixture. This is because the morphology varies depending on the Colloidal Index (Ci) of the base asphalt and the Melt Index (Mi) that is related to the molecular weight of SBS. Also, the microtexture of the coarse aggregate's surface was expressed in a form of Fractal Dimension. It was shown that the fractal dimension had a high correlation with the flow deformation and the compaction properties of the porous mixtures.