Modeling and testing of road surface aggregate wearing behaviour

The amount of urban dust and especially the particulate matter (PM) production is closely related to the wearing resistance of the aggregates on the road surface. In this research, the Aachen Polishing Machine (APM) was used to conduct wearing tests; the APM uses real vehicle tires. The obtained results were analysed with a rubber-road wearing model. Based on the spectral analysis of the texture, the wave length coinciding with the most wear of the specimen surface was identified. Findings show that the decrease of skid resistance can be ascribed to changes in the micro-texture up to 62.8 μm in the polishing test with the APM procedure. The final friction after polishing tests exhibits a positive correlation with the average hardness of the aggregate and the mass percentage of non-fissile mineral. A positive interdependence is observed for the quartz content whilst the calcite content exhibited a negative one. The average height induced by polishing is selected to determine and quantify the abrasion of aggregate. The results show a directly proportional relationship between the abrasion and the contact pressure.