Enhancing pavement durability for dynamic electric charging systems: Adhesion characterization of the charging unit housing to pavement layers

Road electrification, a key strategy for reducing fossil fuel dependence and mitigating greenhouse gas emissions, poses challenges in embedding inductive coils in pavements for dynamic electric vehicle (EV) charging. This study assesses adhesion at the CU housing-pavement interface by measuring maximum shear stress (τ SBT,max ) and analyzing the influence of surface morphology and adhesives through experiments and predictive statistical adhesion models. Laboratory tests were carried out on composite specimens in which CU housing materials—including polybutylene terephthalate/polyethylene terephthalate (PBT/PET), polydimethylsiloxane (PDMS), and Portland cement concrete (PCC)—were bonded to asphalt concrete (AC16) in a Top Configuration or to levelling layers of cement mortar (CM) or epoxy resin mortar (ERM) in a Bottom Configuration. The adhesives used included epoxy resin adhesive (ERA), polyurethane resin adhesive (PRA), and asphalt emulsions (Em, Em2). Adhesion was assessed based on maximum shear stress (τ SBT,max ) and surface characteristics. In the Top configuration, the optimal combination, as determined by the highest τ SBT,max , exceeded 0.8 MPa on average with PBT/PET and PRA at 2500 g/m², or PCC and ERA at 500 g/m². In the Bottom configuration, PBT/PET and PCC with ERM at 500 g/m² of PRA reached τ SBT,max ∼ 2.5 MPa in both CU housings. These findings highlight the importance of adhesive selection, application rate, and surface preparation in achieving mechanical interlocking and enhancing pavement durability. This study contributes to optimizing Wireless Power Transfer (WPT)-enabled pavements, supporting adopting sustainable EV infrastructure. • Adhesion was analyzed using maximum shear stress (τ SBT,max ). • Surface texture was characterized with a Laser Texture Scanner (LTS). • ANCOVA models evaluated adhesion based on material, surface, and adhesive type. • Optimal adhesives and levelling layers enhance bonding performance.