Thermoregulation effect analysis of microencapsulated phase change thermoregulation agent for asphalt pavement

To analyze the latent heat thermoregulation effect of the microencapsulated phase change material (Micro-PCM) on the pavement asphalt mixture, 300 mm x 300 mm x 300 mm outdoor cubic specimen made up of asphalt mixture with the Micro-PCM was prepared. By arranging a sufficient number of temperature sensors inside the specimen, a real-time monitoring system was established to record the temperature variations of the specimen. Two indices, the latent heat accumulated temperature value (LHATV) and latent heat thermoregulation index (LHTI) were proposed to evaluate the latent heat thermoregulation performance of the Micro-PCM under heating and cooling processes. The results showed that the solar radiation and air flow conditions were the important factors affecting the latent heat effect of the Micro-PCM. The responses of the heat transfer process of the Micro-PCM varied at different locations inside the specimen, which caused a difference in the latent heat efficiency. Meanwhile, under the conditions where the ambient temperature changed rapidly, the phase change response inside the specimen would be relatively lagged, the process of latent heat storage was hindered, and the heat couldn't be completely converted to the latent form. It can be conclude that the excessive heating and cooling rates will affect the process of latent heat, the thermoregulation efficiency of the Micro-PCM can be maintained at a high level under the appropriate variable temperature conditions, a medium temperature range and time span. Under these conditions, the Micro-PCM can exert an effective latent heat thermoregulation function to asphalt mixture. (C) 2019 Elsevier Ltd. All rights reserved.