Three-dimensional evaluation method for asphalt pavement texture characteristics

Abstract

To supplement the research on the evaluation method of asphalt pavement texture, novel three-dimensional (3D) methods are proposed. First, 18 different pavement textures were measured in laboratory from asphalt mixture specimens using laser texture scanner (LTS), and the macro-texture and micro-texture were extracted based on spectrum analysis techniques. Then, macro-texture level evaluation indices f8mac and f9mac together with micro-texture level evaluation indices f8mic and f9mic were proposed based on the gray level co-occurrence matrix (GLCM) method, and the determination of hyperparameters angle θ, pixel distance d and vertical resolution v were discussed. Through the correlation analysis and compared with existing conventional evaluation indices, the optimum pavement texture level evaluation index was selected and verified. Additionally, the evaluation index σ of distribution uniformity of pavement texture (DUPT) was proposed based on the uniformity of deviations between sub-surfaces and the average surface of pavement texture. Finally, the correlations of σ with texture profiles were studied. The results show that f8mac and f8mic are determined as the optimum indices for pavement texture level. Mean texture depth has significant correlation with f8mac, and the correlation coefficient R is 0.9611; friction coefficient μ has significant correlation with f8mic, and the R is 0.9422. θ is recommended to be 90°; d and v are set to 52 pixels (0.4953 mm) and 0.01 mm respectively for macro-texture level evaluation; d and v are set to 1 pixel (0.0095 mm) and 0.003 mm respectively for micro-texture level evaluation. Moreover, the effectiveness of σ is also validated by calibrating with standard grooved surface. It can be concluded that the proposed indices in this study are suitable to the evaluation of pavement texture level and pavement texture distribution.