Thermal performance assessment of PCM incorporated cool concrete pavements using numerical analysis

Abstract

Incorporating Phase Change Materials (PCM) through encapsulation is an effective method to regulate the pavement surface temperature. The present study investigates the effect of the thermal properties of concrete and encapsulating material on the cooling potential of PCM incorporated concrete pavements. An enthalpy-porosity based pore-scale heat transfer model was developed that simulates the melting of PCM in concrete pavements subjected to solar radiation. Two types of PCMs, i.e. Organic Mixture 35 (OM 35) and Organic Mixture 42 (OM 42) were incorporated into concrete slabs with the help of expanded clay aggregates (ECA) as PCM carrier. In the top 0.1 m layer of concrete, a total of 98 numbers of ECA-PCM balls of 1 cm diameter were distributed uniformly. The cooling potential of pavements with OM 35 and OM 42 improved by 82.67 % and 81.70 %, respectively with increase in the porosity of ECA from 0.1 to 0.9. Further, as the thermal conductivity of concrete increased from 1.2 to 2.4 W/mK, the cooling potential of OM 35 and OM 42 incorporated pavements increased by 36.48 % and 38.29 %, respectively. However, the thermal conductivity of the encapsulating material showed marginal influence on the cooling potential and therefore may be neglected.