Experimental study on the preparation and physical thermal performance of coral sand-based phase change material concrete composites

Abstract

To promote the application of phase change materials (PCMs) in the field of green building, this research prepared coral sand-based PCM composites by vacuum adsorption method with coral sand as the porous carrier and polyethylene glycol 1000 as phase change material. The thermal and physical properties of the material, and its leakage characteristics after cement encapsulation were investigated through scanning electron microscope (SEM), differential scanning calorimetry (DSC), fourier transform infrared spectrometer (FT-IR), x-ray powder diffractometer (XRD), and thermal gravimetric analysis (TGA). The DSC results indicated that the coral sand-PCM composites had a melting point and latent heat capacity of 28.55℃ and 48.57 J/g, respectively. TGA and thermal cycling test demonstrated that coral sand-based PCM composites had good stability in terms of their chemical structure, thermal degradation, and cycling reliability in latent thermal energy capacity properties. The coral sand-based PCM composites were later prepared as coral sand-based PCM concrete composites by replacing coarse aggregates with different proportions. And the compressive strength of the PCM concrete composites was tested. In addition, the thermal insulation properties of coral sand-based PCM concrete composites were verified through model tests. The results of model test showed that the maximum indoor temperature differences between the Oridinary-0 and CS-50 concrete rooms were 7.45℃ during heating and 2.61℃ during cooling. The strength of coral sand-based concrete still could meet the requirements according to the structural design code at a mass substitution ratio of 50%. The CS-50 composite concrete exhibited acceptable mechanical properties and was able to regulate indoor temperatures and reduce energy consumption in buildings. Therefore, it is suitable for engineering applications.