ABSTRACT

In order to evaluate the fatigue damage of asphalt mixtures under repeated loads, the Digital Image Processing (DIP) was used to investigate the microstructural characteristics of air-voids. A field test track was constructed to reflect the internal states of asphalt pavement, and several cores were drilled to slice into specimens with different air-void ratios. Test temperatures were −10°C, 0°C and 10°C, the internal structures were scanned by X-ray Computed Tomography (X-CT) device before and after fatigue damage, and the influence of air-voids on fatigue damage was investigated. The results indicate that air-void shape and distribution can be measured by X-CT images and reconstructed by DIP effectively; fractal dimension is a quantitative index to represent the complexity of air-void morphology. The effects of temperature and initial air-void ratio on fatigue performance are significantly, and change of air-void ratio presents a linear relation with respect to the complexity of air-void morphology.