Effects of Conductive Fillers on the Dynamic Response and Fatigue life of Conductive Asphalt Concrete

It is currently interesting to use thermal or electrical conductive asphalt concrete for snow-melting and maintenance of asphalt pavements in winter. The addition of conductive fillers may have negative effects on the mechanical properties of asphalt concrete. The performance of conductive asphalt concrete is greatly affected by the initial crack and its propagation. Laboratory tests for neat and conductive asphalt concrete include Dynamic Modulus Test (DMT) and Indirect Tensile Fatigue Test (ITFT). DMT tests indicates that the value of dynamic modulus of asphalt concrete decreases with the increasing graphite content. It means that the conductive asphalt concrete achieves lower stiffness. It can be concluded from ITFT tests that the fatigue life (load cycle times) of conductive asphalt concrete is more than neat ones when stress level is under 1.0 MPa. Meanwhile higher fatigue resistance of conductive asphalt concrete is observed when carbon fibers (2 weight % of total aggregate) were added together with 22% graphite, especially at low stress levels.