The thermoregulation effect of microencapsulated phase-change materials in an asphalt mixture

Abstract

Temperature plays an important role in the long-term performance and service life of pavement. With the large-scale use of asphalt pavement, the paving industry is now more interested in the related pavement distress generated by temperature. Against this background, this paper presents the test results for pure microencapsulated phase change materials (micro-PCMs), as well as asphalt mixtures containing micro-PCMs, with the aim of reducing the temperature difference. The latent heat storage capacity of pure micro-PCMs was evaluated by the T-history method, and Ch was proposed to characterize their latent heat storage capacity. Outdoor experiments were performed to observe the temperature change behavior of seven asphalt mixture specimens manufactured by the wheel-grind method. Two specimens were mixed with −5°C micro-PCMs, with micro-PCM contents of 0.3% and 0.5% respectively, substituting the equivalent amount of mineral filler. Another two specimens were mixed with 0 °C micro-PCMs, with micro-PCM contents of 0.3% and 0.5%. Two other specimens were mixed with 5 °C micro-PCMs, with micro-PCM contents of 0.3% and 0.5%. The results show that the thermoregulation ranges of different micro-PCMs differ. As the micro-PCM content increases, the temperature difference between the ordinary AC-13 asphalt mixture and AC-13 mixed with micro-PCMs increases. The use of 5 °C micro-PCMs in an asphalt mixture can significantly improve its thermal behavior.