Optimizing Thermal Energy Storage in 3D Printed Concrete with Hollow Ceramsite Composite Phase Change Materials (2025-04)¶

3D printing has revolutionized construction, yet integrating phase change materials (PCMs) into 3D printed concrete (3DPC) to enhance energy efficiency remains a major challenge. This study presents a novel approach by incorporating hollow ceramsite composite phase change materials (HC-PCMs) into 3DPC, achieving an innovative balance between thermal energy storage and mechanical performance in thermal energy storage 3D printed concrete (TES-3DPC). Unlike conventional PCM-integration methods, the use of HC-PCMs overcomes leakage issues and enhances structural integrity due to their robust ceramic shell and high adsorption capacity. The impact of HC-PCMs on printing, mechanical, and thermal properties was evaluated. Results indicate that a 10% HC-PCMs content improves fluidity, while a 30% content increases specific heat capacity from 1.25 J/g·°C at 0% to 1.82 J/g·°C, representing a 45.43% increase, significantly enhancing thermal energy storage. Despite reduced extrudability due to particle interlocking, optimized extrusion speed enables successful printing. The compressive strength of the TES-3DPC with 30% HC-PCMs remains at 48.1 MPa, and the elastic modulus is 29.4 GPa, demonstrating that HC-PCMs do not compromise mechanical integrity. Additionally, internal temperature fluctuations in 3D printed models were reduced by 6.8 °C, and the Overheating degree (OD) decreased from 3.3 °C·h to 1.12 oC·h, effectively improving thermal comfort. This study pioneers the integration of hollow ceramsite-based PCMs into 3DPC, offering a promising strategy for developing energy-efficient, thermally stable 3D printed buildings.