Application and performance evaluation of TMUF-MPCMs in concrete pavement: Mechanical behavior and durability investigation

Concrete pavements in cold regions are highly susceptible to deterioration from freeze-thaw cycles, which challenge durability and maintenance. This study investigates the incorporation of 4% and 6% Tetradecane-Melamine-Urea-Formaldehyde microencapsulated phase-change materials (TMUF-MPCMs) in concrete mixtures to improve durability and thermal regulation. Microstructural analysis confirmed the successful synthesis of spherical, thermally stable microcapsules. While the addition of TMUF-MPCMs reduced workability (approximately 20% slump reduction) and compressive strength (by 26% and 30% for the 4% and 6% mixes, respectively), flexural strength improved significantly, with the 6% mixture exceeding FAA requirements. Most notably, TMUF-MPCMs dramatically enhanced freeze-thaw resistance, retaining over 90% of their relative dynamic modulus of elasticity after 300 cycles compared to 76% for conventional concrete, while exhibiting negligible mass loss and crack formation. Microstructural evidence suggests self-healing behavior through calcite precipitation at the microcapsule interfaces. A composite performance index ranked the 6% TMUF-MPCM mixture as optimal, and multi-objective optimization identified 5.9% as the ideal dosage to balance mechanical performance and durability. Despite some reduction in compressive strength, TMUF–MPCMs offer a promising dual-functional strategy to enhance the durability and sustainability of concrete pavements in cold regions. The self-healing response was confined to the microscale. At the same time, the potential reduction in deicer dependence is inferred from laboratory-based thermal and durability enhancements rather than verified under field conditions. • Using MPCMs to enhance durability and thermal regulation of concrete pavements. • Smart concrete behavior observed through self-healing and thermal regulation. • Optimal MPCM content identified around 6% for balanced performance.