Design and Application of Concrete Tiles Enhanced with Microencapsulated Phase-Change Material

Phase-change materials (PCMs) have a high heat of fusion compared to that of traditional material, and for this reason, they are able to store and release larger amounts of energy at their transition temperature. The inclusion of PCMs in buildings has attracted much interest worldwide because of their ability to reduce building energy demand and increase indoor comfort. This paper presents the development and testing results of a concrete tile system with microencapsulated PCMs. The concrete tiles were cast for use in a high-performance house built for the Solar Decathlon China 2013 competition. The paper shows that the addition of PCMs reduced the overall compressive and flexural strength properties of the concrete. A more than 25% decrease in compressive strength was observed with the addition of 20% PCM per volume of concrete. However, a significant improvement in the thermal properties of the concrete tile PCMs was measured. The thermal energy storage capability of the PCM-enhanced concrete tiles was determined using the dynamic heat flowmeter apparatus method. It was demonstrated that a 3.8-cm-thick concrete tile with 13.5% PCM had a thermal storage capacity equivalent to a 5.9-cm-thick tile of regular concrete, a 155% increase in thermal storage capability. Finally, the results indicate that the use of PCM in concrete floor tiles can significantly improve their thermal behavior, especially in lightweight buildings, while also keeping the concrete's strength loss within an acceptable range.