Utilization of micro encapsulated phase change material in asphalt concrete for improving low-temperature properties and delaying black ice

•Mixture additive μPCM could enhance low temperature cracking resistance.•μPCM modified asphalt concrete gained 2 °C higher than that of conventional sample.•Delay freezing time was approximately 1 h 10 min for 1.5% μPCM mixture.•The effectiveness of μPCM remained stable under prolonged service life. Once black ice happens, it strongly reduces the friction of the tire-road surface, resulting in dangerous driving and reducing the performance of asphalt mixture. This study aims to utilize latent heat fusion during phase transition of micro encapsulated phase change material (μPCM) to improve low-temperature performances and delay black ice formation. The properties of asphalt mixture were carried out by several laboratory experiments. Asphalt slabs with μPCM additives were exposed to outdoor winter environment to evaluate the effect of μPCM on temperature regulation. Furthermore, a comparison was studied between fresh and 6-month-old μPCM slabs to investigate the effectivity of μPCM latent heat release. Indirect tensile asphalt cracking results showed that containing 1.5% μPCM (weight of mixture) could increase cracking tolerance index and indirect tensile strength at low temperature (4 °C). Fatigue loading test concluded that all μPCM modified asphalt mixtures are within normally accepted performance, while monotonic loading test indicated that the addition of an appropriate μPCM could improve reflection cracking resistance at low temperature. The presence of μPCM could mitigate low temperature cracking damage by decreasing stiffness and increasing phase angle of asphalt mixture. Besides, the monitored temperature showed that μPCM modified mixture acquired 2 °C higher compared to conventional mixture. The delay freezing was approximately 1 h and 10 min, which may benefit in delay black ice formation. After six months exposed to outdoor conditions, the latent heat fusion of μPCM was still present. Finally, the utilization of μPCM is a promising solution to improve low temperature cracking resistance and delaying black ice formation.