Innovative Dual-Function Heated Pavement System Using Hollow Steel Pipe for Sustainable De-Icing

Winter road safety is threatened by black ice, while traditional de-icing methods, such as chemical spreading and electrically heated pavement systems, raise concerns about environmental impact and economic costs. This study proposed a hydronic heated pavement system utilizing geothermal energy (HHPS-G)-integrated concrete pavement that ensures environmental sustainability and structural stability. The design utilizes hollow steel pipes as both reinforcement and heat exchange conduits, thereby eliminating the need for separate high-density polyethylene (HDPE) pipes. To enhance upward heat transfer, bottom-ash concrete was introduced as an alternative to conventional insulation, providing thermal insulation and structural strength. A validated numerical model was developed to compare the de-icing and snow-melting performance of different pipe types. The results show that hollow steel pipes reduced the time to reach 0 °C on the concrete pavement surface by 30.86% and improved heat flux by 10.19% compared to HDPE. The depth of pipe installation significantly influenced performance: positioning the pipes near the surface achieved the fastest heating (up to 70.11% faster), while mid-depth placement, recommended for structural integrity, still provided substantial thermal benefits. Variations in insulation thermal conductivity below 1 W/m·K had little effect, whereas replacing the base layer with bottom-ash concrete provided both insulation and strength without the need for separate insulation layers.