Lightweight mortar with paraffin/expanded vermiculite-diatomite composite phase change materials: Development, characterization and year-round thermoregulation performance

Abstract

Expanded vermiculite based form stable composite phase change material (EV based FSCPCM) is a promising material to be applied into the field of building energy conservation. However, the thermoregulation performance of building components containing the EV based FSCPCM under real climatic conditions is lacking. In this study, paraffin/expanded vermiculite-diatomite form stable composite phase change material (paraffin/EV-DI FSCPCM) was prepared by a simple method using EV-DI mineral system as the supporting material, and paraffin as the PCM. A new thermal storage light weight cement mortar (TSLCM) was then prepared using it as the aggregate. Subsequently, the year-round applicability of the cement board made from TSLCM was analyzed by using the full-scale testing room built in the outdoor. The results showed that compared with paraffin/EV FSCPCM, the mortar prepared with paraffin/EV-DI FSCPCM had enhanced mechanical properties and thermal stability. In the transition seasons, the use of cement board made from TSLCM in the testing room could continuously regulate the indoor temperature. The fluctuation of the indoor temperature could be reduced by 3.6 °C. For summer, the thermoregulation performance of TSLCM decreases with the increase of temperature at night. In winter, cement board made from TSLCM can reduce the peak temperature of the testing room when the air conditioner is turned off. For the case of using air conditioner for heating, the board can better maintain the indoor temperature.