Texture analysis of aggregates for wearing courses in asphalt pavements

It is well known that the wear of road pavement skid resistance is associated with a change in the geometrical characteristics of the micro- or macro-texture of aggregates of pavement surface. So, a study of the relationship between texture and skid resistance, to find suitable correlations, is of interest for research in road pavement materials. In this work the relationship between adherence and aggregate texture is analyzed, using superficial geometrical profiles, by means of both aggregate descriptors and the power spectral density function (PSD). In particular, a methodology for a surface texture analysis of aggregates for pavement wearing courses is presented which demonstrates the support given by both micro- and macro-texture, resulting in some indicators that can be related to pavement adherence. The results are, also, useful in order to explain the basic physic phenomenon between friction and the surface profile proprieties of aggregates. For research purposes, a procedure was established for the preparation and analysis of aggregates in order to carry out a survey of their geometrical profiles using laboratory samples which underwent an accelerated polishing control test (CLA).