Solar-to-heat conversion control of pavement through thermochromic coating: Integration of thermal management and visual temperature indication

Amid accelerating climate change and unprecedented global energy crisis, conventional pavement surfaces can reach extremely high temperatures during summer months, absorbing substantial solar radiation and transferring heat to the surrounding environment. Despite advances in pavement cooling technologies, existing solutions exhibit limited thermal regulation during peak conditions and lack intuitive monitoring capabilities, creating a significant gap in urban thermal energy management. This study presents a system-level evaluation of yellow thermochromic hybrid coatings for pavement heat mitigation, introducing a novel dual-functional approach that uniquely combines efficient solar reflection technology with intuitive temperature indication capability, achieving effective solar-to-heat conversion control. Hybrid formulations were developed through the integration of thermochromic and conventional yellow pigments to optimize performance. Optical characterization showed the thermochromic formulation CYC-4 exhibits exceptional solar reflectance (78.95 % overall), with superior performance across visible (75.79 %) and near-infrared (92.64 %) regions. Colorimetric measurements confirmed substantial temperature-dependent color transitions at 45 °C, primarily manifested as a reduction in yellowness (Δb∗ = −32.86). The analysis identified the optimized formulation TCYHP-L as the optimal composition for pavement thermal management, achieving surface temperature reductions of 17–18 °C during peak solar hours. Material testing confirmed high thermal stability and uniform microstructure. The coating transitions from yellow to a lighter shade when pavement temperatures rise, providing both effective heat management and clear visual temperature indication through color change. This innovative solution addresses pavement thermal challenges while supporting energy conservation through reduced cooling demands and enhanced infrastructure resilience to temperature extremes.