Evaluating asphalt pavement surface texture using 3D digital imaging

The traditional asphalt mixture surface texture measurement methods cannot provide the distributions of the texture, which is necessary for studying the influence mechanism of texture on tyre/pavement interaction performance. A non-destructive 3-dimensional image-based texture analysis method (3D-ITAM) is developed based on the 3D surface reshaping and spectral analysis techniques. Mixture 3D surface is reshaped based on the photometric stereo method using the acquired tricolour digital images. Spectral indicators representing mixture surface texture distribution properties are calculated from 3D-ITAM software. Additionally, the traditional texture indicator (i.e. mean texture depth) is also calculated. The 3D-ITAM results are confirmed with both macro and micro-texture indicator values from the sand patch method (SPM) and hand-push friction tester (HFT), which are two widely used in practice though they cannot capture the distribution property of surf ace texture. It was demonstrated that the 3D-ITAM results correlate well with SPM and HFT and can be considered as an effective method to characterise the mixture surface texture.