Research on Micro-Structure Evolution of Asphalt Mixture Based on Estimation of Fractal Demensions of CT Image

Meso-structure images of a asphalt mixture under various fatigue levels are investigated by using CT(Computerized Tomograph) scanning in fatigue experiment of asphalt mixture.The fractal dimensions of these meso-structure images are estimated by image analysis and fractal theory.On the basis of the fractal dimension of meso-structure,the characteristics of the evolution of meso-structure are quantitatively analyzed.It is shown that the value of fractal dimensions,derived by the CT image,increases with the evolution of the damage in asphalt mixture.It has suggested that the fractal dimensions defined in the paper can be used as parameter of damage in asphalt mixture.The equation of damage evolution is obtained based on the change of fractal dimension.