Characterization of road surfacing aggregates based on their mineralogical fingerprint

Abstract

To ensure the safety of infrastructure users, the long-term skid resistance is a crucial factor and is determined in large by the mineralogical and morphological characteristics of surfacing aggregate. Most studies have investigated these aggregate properties separately without considering the interrelation between one another. The objective of this study is to consider the morphological characteristics as well as the mineralogical fingerprint of aggregate to develop an innovative approach to optimize the aggregate selection process. The investigations are based on 11 different aggregate types with a broad range of miner-alogy, commonly used in Germany. The long-term influence of polishing and wearing on the surface aggregate was simulated by means of the Aachen Polishing Machine and the Micro-Deval test respectively. To evaluate the impact of these tests, the aggregate shape was characterized by means of an imaging system called Aggregate Image Measurement System while the skid resistance of aggregates was evaluated with the British Pendulum Test. The test results show that the quartz and calcite are the key crystals to determine the anti-wear resistance of aggregates. A correlation between the skid resistance, morphological properties and mineralogy is derived, which proves the mineralogical fingerprint technology is practical for characterization of aggregates used in pavement surface layers.