Three-dimensional survey method of pavement texture using photographic equipment

In this paper, an image-based technique for the assessment of a 3D model of pavement texture is presented. Five common cameras were used to collect pictures of the pavement surface. An innovative procedure was developed, based on volumetric calculation, to calculate the digital Mean Texture Depth (MTD) starting from the Digital Surface Model (DSM) generated by the photos. To validate the procedure, 20 different pavement surfaces were acquired for a total of 100 DSMs. For each model the digital MTD was calculated and compared with the measured MTD performed with the sand patch method, in the same pavement. The coefficients of determination were found for each camera. The results highlighted the high accuracy level of the analysis, with a coefficient of determination from 0.99 to 0.94 in relation to the features of each camera used for the acquisition. In addition, others texture parameters extracted by profiles were calculated and analyzed. At last, a volumetric study was conducted to investigate the pavement behavior in case of rainfall.