An investigation of the electrical conductivity of different stone mastic asphalt mixtures

Abstract

In recent years, many studies on the prevention of icing on highways and airports through the use of electrically conductive asphalt pavements have been carried out. However, although electrical conductivity in asphalt mixtures has been extensively investigated, the gradation in conductive stone mastic asphalt (SMA) mixtures has not yet been studied in detail. The main purpose of this study was to investigate, for the first time, the effect of aggregate gradation variation on the electrical resistivity and temperature change of electrically conductive SMA. Samples of conductive SMA were produced using three different aggregate gradations (series 1A, 2A and 8S) and 5 mm long carbon fibres (0.2% by weight) as the conductive component. Marshall mix design was performed on series 1A, 2A and 8S. The samples were tested for volume resistivity, temperature change under constant electrical voltage and ultrasonic pulse velocity and the results were compared. The results showed that a change in aggregate gradation had a significant effect on the electrical conductivity properties of the conductive SMA, with a denser gradation of the SMA mixture leading to higher electrical conductivity.