Experimental investigation on thermal characterization of PCM-modified hollow blocks for passive thermal regulation in buildings

High energy consumption in buildings highlights the need for sustainable thermal management techniques, such as Phase Change Materials (PCMs) for passive temperature control. This study investigates the use of microencapsulated beeswax PCM in hollow concrete blocks, replacing 1.5% of the cement by weight. Three alternative block groups used 1.5% lime and ground granulated blast-furnace slag as controls, which yielded higher compressive strength.

The PCM-modified blocks exhibited 3.60 N/mm² compressive strength, compared to 2.76 N/mm² for standard blocks. These blocks showed the lowest water absorption and moisture movement, along with the lowest thermal conductivity and highest thermal resistivity. X-ray diffraction and scanning electron microscopy confirmed the integrity of the microencapsulation and hydration processes.

The experimental results demonstrate the effectiveness of PCM-modified hollow blocks for renewable energy storage and passive thermal regulation in buildings. The authors acknowledge the support of their respective institutions.