Preparation of Low-Temperature Phase Change Materials Microcapsules and Its Application to Asphalt Pavement

Asphalt pavement cracks easily in low-temperature environments. In order to address the problem, phase-change material (PCM) microcapsules working at 0–10°C are used to replace some of the aggregates in asphalt. In this study, PCM microcapsules with a high-temperature epoxy resin adhesive as reinforcement phase were prepared by using n-tetradecane/tetradecanol as the core material and melamine-urea-formaldehyde as the wall material. The reinforced PCM microcapsules were blended into the asphalt modified by styrene-butadiene-styrene block copolymer (SBS) modified asphalt, the PCM microcapsules were used to replace part of the same amount of the coarse aggregate. The results depict that the reinforced PCM microcapsules can satisfy the requirements of both immersion Marshall test and freeze-thaw splitting test. Above all, asphalt mixtures containing reinforced PCM microcapsules have been proved acceptable via dynamic stability tests. The bending beam rheometer test results imply that asphalt mixture containing PCM microcapsules revealed good crack resistance at low temperatures. Compared with the asphalt mixture sample in the reference experiment, the temperature difference of that containing the reinforced PCM microcapsules could reach 2.1°C, indicating a promising application prospect.