Potential applications of phase change materials to mitigate freeze-thaw deteriorations in concrete pavement

A study was performed to evaluate the feasibility of using phase change materials (PCMs) to mitigate freeze-thaw deteriorations in concrete pavements. The approach taken in this paper was to reduce the expected number of freeze-thaw cycles by harnessing the latent heat of fusion of a paraffin-based organic PCM with a phase transition temperature of 4.5 °C (N-Tetradecane). To ensure stable and proper functioning of PCM in mortar, the PCM was coated with tiny melamine-formaldehyde resin shells using a microencapsulation technique. A preliminary study verified successful thermal storage/release functions of the PCM microencapsulated with a melamine-formaldehyde resin. Thermal response tests showed that the low-transition temperature PCM has a promising potential to extend the service life of concrete pavements against freeze-thaw deteriorations even though its effect became minimal with prolonged exposure to ambient temperature far below the transition temperature. A microencapsulated PCM (mPCM) inclusion was found to negatively affect the compressive and flexural strengths or mortar, whereas the volume stability at early ages was rather enhanced in the presence of mPCM.