Binary eutectic phase change materials application in cooling asphalt: An assessment for thermal stability and durability

Abstract

Organic eutectic phase change materials (PCM) show great promise as thermal storage agents for regulating the temperature of asphalt pavements. Assessing their aging characteristics and durability when integrated into asphalt is crucial and necessitates further in-depth research. This study evaluates the impact of aging on binders with acid/palmitic acid binary eutectic PCM (SA/PA-PCM). Aging was simulated using the rolling thin film oven (RTFO) and pressure aging vessel (PAV) devices. The current study leads to the conclusion that the use of SA/PA-PCM is promising. Specifically, the incorporation of SA/PA-PCM significantly improves the aging resistance, showcasing notable enhancements in thermal stability, fatigue performance, anti-cracking ability, and thermal regulation of asphalt. Only a 5 % decrease occurred in the melting enthalpy of the binder with 15 % SA/PA-PCM after 60 h of long-term aging (from 32.17 to 25.87 J/g), showing a stable thermal storage ability. The maximum temperature difference and lag is 9.3 °C and 46 min. respectively. To sum up, Asphalt with 15 % SA/PA-PCM surpasses other binders, displaying higher melting latent heat, reduced sulfoxide index, increased long-term aging resistance, and superior stress relaxation capabilities. This research confirms the potential of SA/PA-PCM in asphalt applications, providing a new path for durable and environmentally friendly road infrastructure.