An improved differential box counting method to measure fractal dimensions for pavement surface skid resistance evaluation

Abstract

Fractal dimension had been recognized as a texture indicator to evaluate skid resistance performance of pavement surface. One of the most frequently used methodologies to measure fractal dimension is differential box counting (DBC). This paper proposes an improved DBC (IMDBC) to estimate fractal dimension of three-dimensional (3D) pavement texture image based on grid displacement mechanism. Considering the contact characteristics between pavement surface and tire, the most suitable fractal texture surface for skid resistance is found based on the fractal and stratification method. The IMDBC improves the fitting accuracy by 18.8% (complete texture) and 900% (partial texture) compared to the traditional DBC. The correlation coefficient between the fractal dimension and friction reaches up to 0.6 when vertical height ratio is 0.5 ~ 0.6 h, which means that the proposed fractal dimension indicator of the upper layer texture could be used as a potential parameter to evaluate pavement surface skid resistance performance.