Heat Propagation Around a Nanothermal Rod in Asphalt Concrete Studied by Multiscale Modeling and Experimental Characterization

Abstract

Ice formation on pavement surfaces near tunnel openings in alpine regions poses significant safety risks. While nanothermal rod offer a promising solution, their heat transfer mechanisms and thermal-affected range in asphalt concrete remain poorly understood, particularly regarding interfacial thermal resistance and heat propagation in heterogeneous materials. This study establishes a multiscale heat transfer model to analyze the spatiotemporal temperature distribution around a nanothermal rod embedded in asphalt concrete. The model incorporates effective thermal conductivity of the composite and boundary conditions reflecting realistic pavement environments. Numerical simulations validate the model’s accuracy, demonstrating a 98% agreement with experimental data under varying power inputs (10 to 40 W/m) and ambient temperatures(−20°C to −5°C). Laboratory experiments using infrared thermography further confirm that the effective heat transfer radius reaches 7cm at −5°C with 30 W/m heating, enabling a recommended rod spacing of 10cm for uniform deicing. This work not only advances the fundamental understanding of nanoscale heat transfer in composite materials but also offers a validated design tool for energy-efficient pavement thermal management systems.

Keywords: nanothermal rod, asphalt concrete, heat mangement, expermential validation