Study on the Workability and Mechanical Properties of Pavement Concrete Modified with Graphite-tetradecane Phase Change Material

In this paper, the effect of graphite-tetradecane phase change material (G-t PCM) on pavement concrete's mechanical properties and frost resistance was investigated. Different dosages of G-t PCM (0%, 4%, 8%, and 12%) were used to prepare modified concrete, and the effects of G-t PCM on the properties of concrete were systematically evaluated by compressive strength, flexural strength, and rapid freeze-thaw tests. The findings demonstrated that as the dosage of G-t PCM increased, concrete's compressive and flexural strengths tended to drop; the most significant loss was seen at a dosage of 12%. However, the introduction of G-t PCM significantly improved the frost resistance of concrete, especially the composite phase change material with 8% dosage (phase change temperatures of 5°C and -5°C, respectively), which showed the best frost resistance. The study showed that precise regulation of the dose of G-t PCM may significantly improve the frost resistance of concrete without considerably compromising its mechanical qualities, offering a novel approach to increase the longevity of pavement concrete.