Physico-mechanical properties and thermal monitoring performance of thermal enhanced cement slurry-coated LWAs containing microencapsulated phase change material

Abstract

Over the past decade, phase change materials (PCMs) have emerged as promising solutions for thermal energy storage (TES) systems, aimed at minimizing heating and cooling energy requirements in buildings. Nevertheless, despite their potential, there are some significant challenges in effectively integrating PCMs into building components. As part of this study, lightweight aggregates (LWA) were coated with a cement slurry containing microencapsulated phase change material (MPCM) to produce lightweight concrete (LWC) with the aim of investigating its mechanical and thermal properties. The LWAs were coated with MPCM at proportions of 2.5%, 5%, and 7.5% of their weight, and an LWC-MPCM was produced using these coated aggregates. The LWC-MPCM exhibited a decrease in dry unit weight up to 1248 kg/m3 and a reduction in thermal conductivity up to 0.60 W/mK with negligible loss of strength. SEM examinations revealed that the cement slurry coating provided strong adhesion to the aggregates, resulting in a robust concrete-aggregate interface. The room with the LWC-MPCM experienced a decrease of approximately 0.23 °C in center temperature compared to the reference room during the daytime. Additionally, after sunset, the LWC-MPCM showed an increase of approximately 1 °C in room center temperature. These advantageous physico-mechanical and thermal properties establish LWC-MPCMs as promising and energy-efficient components for producing thermo-regulative building materials.