Contribution of multiscale analysis to the understanding of friction evolution of aggregates surfaces

In this paper, a multiscale texture analysis method is developped and applied to aggregates surfaces to better explain the variation of road friction during polishing process. This method is based on continuous wavelets decomposition. The study is done on five aggregates types by varying aggregates hardness and mineralogical composition. Polishing tests and friction measurement are performed on each formula using Wehner & Schulze appartus to follow the evolution of friction with polishing. At each polishing stage, 3D mapping are made using Alicona Infinite Focus Sensor to follow the evolution of the surface texture. On these cartographies, multiscale texture parameters are calculated and analysed. Correlations between theses parameters and friction show that scales ranging between 0 and 1000 mu m seem to be the most relevant to explain friction evolution.