Effect of Phase Change Materials on Optimization of Thermal Properties of Concrete

Abstract

This research investigates the impact of micro-encapsulated phase change materials (micro-PCMs) on the thermal performance and mechanical properties of concrete, specifically focusing on improving energy efficiency in buildings. Four concrete mixtures were studied: one control mix without micro-PCMs and three mixes containing 7.5%, 15%, and 30% micro-PCMs added to the cement content. The slump, density, compressive strength, thermal conductivity, and temperature changes over time were measured. The results show that incorporating micro-PCMs improves workability to 16% for the mix containing 30% PCM. The unit weight of the concrete decreased with an increase of PCM reduction of up to 4.6% at 30% micro-PCM content. However, there was a significant decline in compressive strength, with reductions to 12.2 and 20.1 MPa after 7 and 28 days for the mix of 30% PCM. Adding micro-PCMs significantly reduced thermal conductivity by as much as 49.2%, enhancing the insulation performance of 30% PCM. The heat transfer analysis indicated that integrating PCMs lowers peak temperatures to 25%, delaying the time to reach peak temperature.