Magnetically responsive asphalt materials for smart infrastructure: Characterization and potential in remote sensing applications

This study investigates the incorporation of magnetically responsive materials into asphalt mixtures to support the development of smart and functional road infrastructure. Asphalt concrete specimens were formulated by progressively replacing conventional calcium carbonate filler with synthetic magnetite at substitution levels ranging from 0% (reference) to 100%, including intermediate steps at 25%, 50%, and 75%. The resulting mixtures were evaluated through standardized mechanical tests, as well as electrical and magnetic measurements designed to assess their interaction with externally applied electromagnetic fields. A key component of the electromagnetic characterization was the evaluation of wireless power transfer (WPT) performance. Experimental testing using coil systems demonstrated that magnetite-modified asphalt mixtures exhibited higher energy transfer efficiency compared to conventional mixtures, indicating their potential to act as functional intermediaries in dynamic charging systems for electric vehicles. Additionally, the research explores the potential feasibility of implementing passive magnetic coding within the pavement by spatially varying the magnetite content. These embedded magnetic patterns can be detected by vehicle-mounted sensors, enabling applications such as vehicle localization, identification of functional zones, and activation of dynamic charging segments. The findings highlight the dual mechanical and electromagnetic functionality of magnetite-enhanced asphalt, supporting its potential integration into wireless power transfer and remote sensing-enabled infrastructure and contributing to the advancement of intelligent transportation systems in both urban and interurban environments.