Application of Fractal Theory in Pavement Surface Texture Measurement

This paper presents a non-contact method measuring asphalt pavement surface texture based image processing technology and fractal theory to overcome the deficiencies of conventional volumetric method. The pavement surface texture images are acquired using ordinary CCD camera. Then fractal analysis on contour of gray level, which is extracted from binary image by target segmentation at adaptive threshold value and edge detection, is made. A fractal dimension of contour of gray level, scale-independent, is determined. This study comprises field tests and laboratory tests. A regression equation of FDC and MTD measured by sand patch test is built, and a statistical correlation based on a good coefficient of determination (R²) for the data is obtained in the preliminary results. It is observed that the FDC decreases with the MTD. At last, the possibility of replacing volumetric by this measurement in the practical application is discussed.