Development, characterization, and performance analysis of shape-stabilized phase change material included-geopolymer for passive thermal management of buildings

The cooperation between phase change materials (PCMs) and geopolymer (GP) is energy-efficient way for improving the thermal performance of construction materials. This study discusses the effect of PCM combination with GP matrix on obtained concretes' mechanical and thermal properties. Attapulgite/lauric-capric acid eutectic mixture (ATP/LCEM) composite was fabricated as shape-stable composite phase change material (SSPCM) and then integrated with GP concrete (GPC) for improvement of the thermal mass of buildings. Thermal, mechanical, physical, morphological, thermal energy storage (TES) characteristics, and solar thermoregulation performances of the developed GPC-SSPCMs were experimentally characterized. The compressive strength was found over 6 MPa for GPC without aggregates (only SSPCM). The compressive and flexural strengths were relatively low, but above the requirements of the current standards. Other properties as thermal conductivity and solar performance make the produced GPC-SSPCMs promising materials for advanced TES applications in buildings. The apparent porosity was around 45% for GPC-SSPCM-50 and 63% for GPC-SSPCM-100, while water adsorption around 21% for GPC-SSPCM-50 and 30% for GPC-SSPCM-100. Thermal conductivity values of 0.375 W/mK for GPC without aggregates recommended this material as an insulator. The produced SSPCM composite melts at 19.00°C with corresponding latent heat of 73.9 J/g, while the GPC-SSPCM melts at 18.30°C with corresponding latent heat of 6.57 J/g. Based on the obtained outcomes, the energy-saving was determined as 5.56 kWh, which is corresponding to the CO₂ saving of 15 kg-CO₂, 14.68 kg-CO₂, and 2.41 kg-CO₂ in case of using coal, natural gas, or electricity, respectively as energy source.