Effect of expanded graphite/polyethylene glycol composite phase change material (EP-CPCM) on thermal and pavement performance of asphalt mixture

Abstract

The application of phase change materials (PCMs) to the temperature regulation of asphalt pavements has recently become a hot topic of research. At the same time, studies concerning the influence of PCMs on the thermal and pavement performance of asphalt mixtures are still rarely available. The primary objective of this study was to reveal the effect of an expanded graphite/polyethylene glycol composite phase change material (EP-CPCM) on the thermal and pavement performance of asphalt mixtures. EP-CPCM was incorporated into an AC-13 asphalt mixture at various dosages. First, the thermal performance, including thermal constants and thermal regulation effects of the EP-CPCM-modified asphalt mixtures was evaluated, followed by an investigation of the pavement performance in terms of rutting and cracking resistance, moisture stability, and fatigue resistance. The results indicate that by reducing the heating and cooling rates as well as extending the heating and cooling times, EP-CPCM can regulate the temperature of asphalt pavements. The thermal balance inside the pavement and heat exchange between pavement and the ambient environment also improved. The rutting resistance and cracking resistance of asphalt mixtures were enhanced, mainly when the dosage of EP-CPCM was limited. However, the adverse effects of EP-CPCM on the moisture stability under hot water conditions, freeze-thaw conditions, fatigue life, and stress sensitivity gradually emerged when the dosage of EP-CPCM increased.