Microencapsulated Phase Change Material in 3d-Printable Mortars

Abstract

The present study investigates the potential of replacing sand with microencapsulated phase change materials (MEPCM) in 3D printable mortar to provide a promising way to improve printability and thermal performance in 3D-printed buildings. The first part of the paper includes a systematic methodology that involves evaluating the properties of fresh and hardened mortars containing different volumes of MEPCM and evaluating the thermal properties of various mix designs. The findings showed that while the mortar without MEPCM was not printable, adding MEPCM increased the printing time, yield stress, and viscosity. Furthermore, the integration of MEPCM resulted in a significant retardation effect on the setting time by up to 200%. Microstructural analysis via SEM highlighted intact MEPCM in the cementitious matrix, although a decrease in mechanical strength of up to 53% was observed after 28 days. However, all mix designs maintained acceptable mechanical strength according to standards. The second part focuses on the experimental-numerical thermal performance of a printed wall where MEPCM replaced 80% of the sand. In this part, finite element-based (FEM) simulations confirmed the experimental findings and showed a significant energy reduction of 40.4% for this mix design compared to mortar without MEPCM under real weather conditions.

Keywords: Mortar, microencapsulated PCM, 3D printing, Portland cement, Energy reduction