Effect of Steel Wool and Graphite on the Electrical Conductivity and Pavement Properties of Asphalt Mixture

Electrically conductive asphalt mixtures (ECAM) were fabricated by adding two conductive materials (steel wool and graphite) in this paper. Effects of steel wool and graphite on the electrical conductivity and pavement properties of ECAM were studied. Results showed that steel wool can greatly reduce the electrical resistivity of asphalt mixtures. Meanwhile, ECAM with steel wool has an excellent low-temperature cracking resistance and a good moisture susceptibility and rutting resistance compared with the plain asphalt mixture. However, the aggregation problem of steel wool cannot be avoided at its high content. As a result, there is an upper limit of the content of steel wool. Graphite can not only effectively decrease the electrical resistivity of asphalt mixture but also has a good rutting resistance, and it can be easily dispersed in the mixture. To fabricate a uniform ECAM with better electrical conductivity and pavement properties, the hybrid addition of steel wool and graphite is employed. This method can reduce the steel wool content, thus solving the dispersion problem and further improving the electrical conductivity and pavement properties of asphalt mixture. Therefore, the hybrid addition method is more suitable for fabricating conductive asphalt mixtures.